1
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Kubrak O, Jørgensen AF, Koyama T, Lassen M, Nagy S, Hald J, Mazzoni G, Madsen D, Hansen JB, Larsen MR, Texada MJ, Hansen JL, Halberg KV, Rewitz K. LGR signaling mediates muscle-adipose tissue crosstalk and protects against diet-induced insulin resistance. Nat Commun 2024; 15:6126. [PMID: 39033139 PMCID: PMC11271308 DOI: 10.1038/s41467-024-50468-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 07/04/2024] [Indexed: 07/23/2024] Open
Abstract
Obesity impairs tissue insulin sensitivity and signaling, promoting type-2 diabetes. Although improving insulin signaling is key to reversing diabetes, the multi-organ mechanisms regulating this process are poorly defined. Here, we screen the secretome and receptome in Drosophila to identify the hormonal crosstalk affecting diet-induced insulin resistance and obesity. We discover a complex interplay between muscle, neuronal, and adipose tissues, mediated by Bone Morphogenetic Protein (BMP) signaling and the hormone Bursicon, that enhances insulin signaling and sugar tolerance. Muscle-derived BMP signaling, induced by sugar, governs neuronal Bursicon signaling. Bursicon, through its receptor Rickets, a Leucine-rich-repeat-containing G-protein coupled receptor (LGR), improves insulin secretion and insulin sensitivity in adipose tissue, mitigating hyperglycemia. In mouse adipocytes, loss of the Rickets ortholog LGR4 blunts insulin responses, showing an essential role of LGR4 in adipocyte insulin sensitivity. Our findings reveal a muscle-neuronal-fat-tissue axis driving metabolic adaptation to high-sugar conditions, identifying LGR4 as a critical mediator in this regulatory network.
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Affiliation(s)
- Olga Kubrak
- Department of Biology, University of Copenhagen, 2100, Copenhagen O, Denmark
| | - Anne F Jørgensen
- Department of Biology, University of Copenhagen, 2100, Copenhagen O, Denmark
- Novo Nordisk, Novo Nordisk Park, 2760, Maaløv, Denmark
| | - Takashi Koyama
- Department of Biology, University of Copenhagen, 2100, Copenhagen O, Denmark
| | - Mette Lassen
- Department of Biology, University of Copenhagen, 2100, Copenhagen O, Denmark
| | - Stanislav Nagy
- Department of Biology, University of Copenhagen, 2100, Copenhagen O, Denmark
| | - Jacob Hald
- Novo Nordisk, Novo Nordisk Park, 2760, Maaløv, Denmark
| | | | - Dennis Madsen
- Novo Nordisk, Novo Nordisk Park, 2760, Maaløv, Denmark
| | - Jacob B Hansen
- Department of Biology, University of Copenhagen, 2100, Copenhagen O, Denmark
| | - Martin Røssel Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230, Odense, Denmark
| | - Michael J Texada
- Department of Biology, University of Copenhagen, 2100, Copenhagen O, Denmark
| | | | - Kenneth V Halberg
- Department of Biology, University of Copenhagen, 2100, Copenhagen O, Denmark
| | - Kim Rewitz
- Department of Biology, University of Copenhagen, 2100, Copenhagen O, Denmark.
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2
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Diao F, Vasudevan D, Heckscher ES, White BH. Hox gene-specific cellular targeting using split intein Trojan exons. Proc Natl Acad Sci U S A 2024; 121:e2317083121. [PMID: 38602904 PMCID: PMC11047080 DOI: 10.1073/pnas.2317083121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 03/07/2024] [Indexed: 04/13/2024] Open
Abstract
The Trojan exon method, which makes use of intronically inserted T2A-Gal4 cassettes, has been widely used in Drosophila to create thousands of gene-specific Gal4 driver lines. These dual-purpose lines provide genetic access to specific cell types based on their expression of a native gene while simultaneously mutating one allele of the gene to enable loss-of-function analysis in homozygous animals. While this dual use is often an advantage, the truncation mutations produced by Trojan exons are sometimes deleterious in heterozygotes, perhaps by creating translation products with dominant negative effects. Such mutagenic effects can cause developmental lethality as has been observed with genes encoding essential transcription factors. Given the importance of transcription factors in specifying cell type, alternative techniques for generating specific Gal4 lines that target them are required. Here, we introduce a modified Trojan exon method that retains the targeting fidelity and plug-and-play modularity of the original method but mitigates its mutagenic effects by exploiting the self-splicing capabilities of split inteins. "Split Intein Trojan exons" (siTrojans) ensure that the two truncation products generated from the interrupted allele of the native gene are trans-spliced to create a full-length native protein. We demonstrate the efficacy of siTrojans by generating a comprehensive toolkit of Gal4 and Split Gal4 lines for the segmentally expressed Hox transcription factors and illustrate their use in neural circuit mapping by targeting neurons according to their position along the anterior-posterior axis. Both the method and the Hox gene-specific toolkit introduced here should be broadly useful.
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Affiliation(s)
- Fengqiu Diao
- Laboratory of Molecular Biology, Section on Neural Function, National Institute of Mental Health, NIH, Bethesda, MD20892
| | - Deeptha Vasudevan
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL60637
| | - Ellie S. Heckscher
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL60637
| | - Benjamin H. White
- Laboratory of Molecular Biology, Section on Neural Function, National Institute of Mental Health, NIH, Bethesda, MD20892
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3
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Ma M, Zheng Y, Lu S, Pan X, Worley KC, Burrage LC, Blieden LS, Allworth A, Chen WL, Merla G, Mandriani B, Rosenfeld JA, Li-Kroeger D, Dutta D, Yamamoto S, Wangler MF, Glass IA, Strohbehn S, Blue E, Prontera P, Lalani SR, Bellen HJ. De novo variants in PLCG1 are associated with hearing impairment, ocular pathology, and cardiac defects. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.08.23300523. [PMID: 38260438 PMCID: PMC10802640 DOI: 10.1101/2024.01.08.23300523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Phospholipase C isozymes (PLCs) hydrolyze phosphatidylinositol 4,5-bisphosphate into inositol 1,4,5-trisphosphate and diacylglycerol, important signaling molecules involved in many cellular processes. PLCG1 encodes the PLCγ1 isozyme that is broadly expressed. Hyperactive somatic mutations of PLCG1 are observed in multiple cancers, but only one germline variant has been reported. Here we describe three unrelated individuals with de novo heterozygous missense variants in PLCG1 (p.Asp1019Gly, p.His380Arg, and p.Asp1165Gly) who exhibit variable phenotypes including hearing loss, ocular pathology and cardiac septal defects. To model these variants in vivo, we generated the analogous variants in the Drosophila ortholog, small wing (sl). We created a null allele slT2A and assessed the expression pattern. sl is broadly expressed, including in wing discs, eye discs, and a subset of neurons and glia. Loss of sl causes wing size reductions, ectopic wing veins and supernumerary photoreceptors. We document that mutant flies exhibit a reduced lifespan and age-dependent locomotor defects. Expressing wild-type sl in slT2A mutant rescues the loss-of-function phenotypes whereas expressing the variants causes lethality. Ubiquitous overexpression of the variants also reduces viability, suggesting that the variants are toxic. Ectopic expression of an established hyperactive PLCG1 variant (p.Asp1165His) in the wing pouch causes severe wing phenotypes, resembling those observed with overexpression of the p.Asp1019Gly or p.Asp1165Gly variants, further arguing that these two are gain-of-function variants. However, the wing phenotypes associated with p.His380Arg overexpression are mild. Our data suggest that the PLCG1 de novo heterozygous missense variants are pathogenic and contribute to the features observed in the probands.
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Affiliation(s)
- Mengqi Ma
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | - Yiming Zheng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
- Current affiliation: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - Shenzhao Lu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | - Xueyang Pan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | - Kim C. Worley
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lindsay C. Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lauren S. Blieden
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Aimee Allworth
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Wei-Liang Chen
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
- Current affiliation: Children’s National Medical Center and George Washington University, Washington DC 20010, USA
| | - Giuseppe Merla
- Laboratory of Regulatory & Functional Genomics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia 71013, Italy
- Department of Molecular Medicine & Medical Biotechnology, University of Naples Federico II, Naples 80131, Italy
| | - Barbara Mandriani
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, Bari 70121, Italy
| | - Jill A. Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - David Li-Kroeger
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Debdeep Dutta
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | - Michael F. Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | | | - Ian A. Glass
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
- Division of Genetic Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195, USA
- Brotman Baty Institute, Seattle, WA 98195, USA
| | - Sam Strohbehn
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Elizabeth Blue
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
- Brotman Baty Institute, Seattle, WA 98195, USA
- Institute for Public Health Genetics, University of Washington, Seattle, WA 98195, USA
| | - Paolo Prontera
- Medical Genetics Unit, Hospital of Perugia, Perugia 06129, Italy
| | - Seema R. Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hugo J. Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
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4
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Zhang S, Wu S, Yao R, Wei X, Ohlstein B, Guo Z. Eclosion muscles secrete ecdysteroids to initiate asymmetric intestinal stem cell division in Drosophila. Dev Cell 2024; 59:125-140.e12. [PMID: 38096823 DOI: 10.1016/j.devcel.2023.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/05/2023] [Accepted: 11/14/2023] [Indexed: 01/11/2024]
Abstract
During organ development, tissue stem cells first expand via symmetric divisions and then switch to asymmetric divisions to minimize the time to obtain a mature tissue. In the Drosophila midgut, intestinal stem cells switch their divisions from symmetric to asymmetric at midpupal development to produce enteroendocrine cells. However, the signals that initiate this switch are unknown. Here, we identify the signal as ecdysteroids. In the presence of ecdysone, EcR and Usp promote the expression of E93 to suppress Br expression, resulting in asymmetric divisions. Surprisingly, the primary source of pupal ecdysone is not from the prothoracic gland but from dorsal internal oblique muscles (DIOMs), a group of transient skeletal muscles that are required for eclosion. Genetic analysis shows that DIOMs secrete ecdysteroids during mTOR-mediated muscle remodeling. Our findings identify sequential endocrine and mechanical roles for skeletal muscle, which ensure the timely asymmetric divisions of intestinal stem cells.
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Affiliation(s)
- Song Zhang
- Department of Medical Genetics, School of Basic Medicine, Institute for Brain Research, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Song Wu
- Department of Medical Genetics, School of Basic Medicine, Institute for Brain Research, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Ruining Yao
- Department of Medical Genetics, School of Basic Medicine, Institute for Brain Research, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Xueying Wei
- Department of Medical Genetics, School of Basic Medicine, Institute for Brain Research, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Benjamin Ohlstein
- Children's Research Institute and Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Zheng Guo
- Department of Medical Genetics, School of Basic Medicine, Institute for Brain Research, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; Cell Architecture Research Center, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China.
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5
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Palumbo RJ, Yang Y, Feigon J, Hanes SD. Catalytic activity of the Bin3/MePCE methyltransferase domain is dispensable for 7SK snRNP function in Drosophila melanogaster. Genetics 2024; 226:iyad203. [PMID: 37982586 PMCID: PMC10763541 DOI: 10.1093/genetics/iyad203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 10/27/2023] [Accepted: 11/13/2023] [Indexed: 11/21/2023] Open
Abstract
Methylphosphate Capping Enzyme (MePCE) monomethylates the gamma phosphate at the 5' end of the 7SK noncoding RNA, a modification thought to protect 7SK from degradation. 7SK serves as a scaffold for assembly of a snRNP complex that inhibits transcription by sequestering the positive elongation factor P-TEFb. While much is known about the biochemical activity of MePCE in vitro, little is known about its functions in vivo, or what roles-if any-there are for regions outside the conserved methyltransferase domain. Here, we investigated the role of Bin3, the Drosophila ortholog of MePCE, and its conserved functional domains in Drosophila development. We found that bin3 mutant females had strongly reduced rates of egg-laying, which was rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 promotes fecundity by repressing P-TEFb. bin3 mutants also exhibited neuromuscular defects, analogous to a patient with MePCE haploinsufficiency. These defects were also rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 and MePCE have conserved roles in promoting neuromuscular function by repressing P-TEFb. Unexpectedly, we found that a Bin3 catalytic mutant (Bin3Y795A) could still bind and stabilize 7SK and rescue all bin3 mutant phenotypes, indicating that Bin3 catalytic activity is dispensable for 7SK stability and snRNP function in vivo. Finally, we identified a metazoan-specific motif (MSM) outside of the methyltransferase domain and generated mutant flies lacking this motif (Bin3ΔMSM). Bin3ΔMSM mutant flies exhibited some-but not all-bin3 mutant phenotypes, suggesting that the MSM is required for a 7SK-independent, tissue-specific function of Bin3.
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Affiliation(s)
- Ryan J Palumbo
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Yuan Yang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Steven D Hanes
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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6
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Nakato E, Baker S, Kinoshita-Toyoda A, Knudsen C, Lu YS, Takemura M, Toyoda H, Nakato H. In vivo activities of heparan sulfate differentially modified by NDSTs during development. PROTEOGLYCAN RESEARCH 2024; 2:e17. [PMID: 38616954 PMCID: PMC11011245 DOI: 10.1002/pgr2.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 02/02/2024] [Indexed: 04/16/2024]
Abstract
Heparan sulfate proteoglycans (HSPGs) serve as co-receptors for growth factor signaling during development. It is well known that the level and patterns of sulfate groups of heparan sulfate (HS) chains, or HS fine structures, have a major impact on HSPG function. On the other hand, the physiological significance of other structural features of HS, including NS/NA domain organization, remains to be elucidated. A blueprint of the HS domain structures is mainly controlled by HS N-deacetylase/N-sulfotransferases (NDSTs). To analyze in vivo activities of differentially modified HS, we established two knock-in (KI) Drosophila strains with the insertion of mouse Ndst1 (mNdst1) or Ndst2 (mNdst2) in the locus of sulfateless (sfl), the only Drosophila NDST. In these KI lines, mNDSTs are expressed from the sfl locus, in the level and patterns identical to the endogenous sfl gene. Thus, phenotypes of Ndst1 KI and Ndst2KI animals reflect the ability of HS structures made by these enzymes to rescue sfl mutation. Remarkably, we found that mNdst1 completely rescued the loss of sfl. mNdst2 showed a limited rescue ability, despite a higher level of HS sulfation compared to HS in mNdst1 KI. Our study suggests that independent of sulfation levels, additional HS structural features controlled by NDSTs play key roles during tissue patterning.
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Affiliation(s)
- Eriko Nakato
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota, USA
| | - Sarah Baker
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota, USA
| | | | - Collin Knudsen
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota, USA
| | - Yi-Si Lu
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota, USA
| | | | - Hidenao Toyoda
- Faculty of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Hiroshi Nakato
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota, USA
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7
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Cortez CT, Murphy RO, Owens IM, Beckmann JF. Use of Drosophila Transgenics to Identify Functions for Symbiont Effectors. Methods Mol Biol 2024; 2739:301-320. [PMID: 38006559 DOI: 10.1007/978-1-0716-3553-7_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Wolbachia, one of the most successful and studied insect symbionts, and Drosophila, one of the most understood model insects, can be exploited as complementary tools to unravel mechanisms of insect symbiosis. Although Wolbachia itself cannot be grown axenically as clonal isolates or genetically manipulated by standard methods, its reproductive phenotypes, including cytoplasmic incompatibility (CI), have been elucidated using well-developed molecular tools and precise transgenic manipulations available for Drosophila melanogaster. Current research only scratches the surface of how Drosophila can provide a tool for understanding Wolbachia's evolutionary success and the molecular roles of its genetic elements. Here, we briefly outline basic methodologies inherent to transgenic Drosophila systems that have already contributed significant advances in understanding CI, but may be unfamiliar to those who lack experience in Drosophila genetics. In the future, these approaches will continue providing significant insights into Wolbachia that undoubtedly will be extended to other insect symbionts and their biological capabilities.
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Affiliation(s)
- Carai T Cortez
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Richard O Murphy
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Isabella M Owens
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - John F Beckmann
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA.
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Bazzi W, Monticelli S, Delaporte C, Riet C, Giangrande A, Cattenoz PB. Gcm counteracts Toll-induced inflammation and impacts hemocyte number through cholinergic signaling. Front Immunol 2023; 14:1293766. [PMID: 38035083 PMCID: PMC10684909 DOI: 10.3389/fimmu.2023.1293766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 10/26/2023] [Indexed: 12/02/2023] Open
Abstract
Hemocytes, the myeloid-like immune cells of Drosophila, fulfill a variety of functions that are not completely understood, ranging from phagocytosis to transduction of inflammatory signals. We here show that downregulating the hemocyte-specific Glial cell deficient/Glial cell missing (Glide/Gcm) transcription factor enhances the inflammatory response to the constitutive activation of the Toll pathway. This correlates with lower levels of glutathione S-transferase, suggesting an implication of Glide/Gcm in reactive oxygen species (ROS) signaling and calling for a widespread anti-inflammatory potential of Glide/Gcm. In addition, our data reveal the expression of acetylcholine receptors in hemocytes and that Toll activation affects their expressions, disclosing a novel aspect of the inflammatory response mediated by neurotransmitters. Finally, we provide evidence for acetylcholine receptor nicotinic acetylcholine receptor alpha 6 (nAchRalpha6) regulating hemocyte proliferation in a cell autonomous fashion and for non-cell autonomous cholinergic signaling regulating the number of hemocytes. Altogether, this study provides new insights on the molecular pathways involved in the inflammatory response.
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Affiliation(s)
- Wael Bazzi
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Sara Monticelli
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Claude Delaporte
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Céline Riet
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Angela Giangrande
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Pierre B. Cattenoz
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
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9
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Aimino MA, Humenik J, Parisi MJ, Duhart JC, Mosca TJ. SynLight: a bicistronic strategy for simultaneous active zone and cell labeling in the Drosophila nervous system. G3 (BETHESDA, MD.) 2023; 13:jkad221. [PMID: 37757863 PMCID: PMC10627267 DOI: 10.1093/g3journal/jkad221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 07/14/2023] [Accepted: 09/17/2023] [Indexed: 09/29/2023]
Abstract
At synapses, chemical neurotransmission mediates the exchange of information between neurons, leading to complex movement, behaviors, and stimulus processing. The immense number and variety of neurons within the nervous system make discerning individual neuron populations difficult, necessitating the development of advanced neuronal labeling techniques. In Drosophila, Bruchpilot-Short and mCD8-GFP, which label presynaptic active zones and neuronal membranes, respectively, have been widely used to study synapse development and organization. This labeling is often achieved via the expression of 2 independent constructs by a single binary expression system, but expression can weaken when multiple transgenes are expressed by a single driver. Recent work has sought to circumvent these drawbacks by developing methods that encode multiple proteins from a single transcript. Self-cleaving peptides, specifically 2A peptides, have emerged as effective sequences for accomplishing this task. We leveraged 2A ribosomal skipping peptides to engineer a construct that produces both Bruchpilot-Short-mStraw and mCD8-GFP from the same mRNA, which we named SynLight. Using SynLight, we visualized the putative synaptic active zones and membranes of multiple classes of olfactory, visual, and motor neurons and observed the correct separation of signal, confirming that both proteins are being generated separately. Furthermore, we demonstrate proof of principle by quantifying synaptic puncta number and neurite volume in olfactory neurons and finding no difference between the synapse densities of neurons expressing SynLight or neurons expressing both transgenes separately. At the neuromuscular junction, we determined that the synaptic puncta number labeled by SynLight was comparable to the endogenous puncta labeled by antibody staining. Overall, SynLight is a versatile tool for examining synapse density in any nervous system region of interest and allows new questions to be answered about synaptic development and organization.
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Affiliation(s)
- Michael A Aimino
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Jesse Humenik
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Michael J Parisi
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Juan Carlos Duhart
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Timothy J Mosca
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
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10
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Goldner AN, Fessehaye SM, Rodriguez N, Mapes KA, Osterfield M, Doubrovinski K. Evidence that tissue recoil in the early Drosophila embryo is a passive not active process. Mol Biol Cell 2023; 34:br16. [PMID: 37405768 PMCID: PMC10551697 DOI: 10.1091/mbc.e22-09-0409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 07/06/2023] Open
Abstract
Understanding tissue morphogenesis is impossible without knowing the mechanical properties of the tissue being shaped. Although techniques for measuring tissue material properties are continually being developed, methods for determining how individual proteins contribute to mechanical properties are very limited. Here, we developed two complementary techniques for the acute inactivation of spaghetti squash (the Drosophila myosin regulatory light chain), one based on the recently introduced (auxin-inducible degron 2 (AID2) system, and the other based on a novel method for conditional protein aggregation that results in nearly instantaneous protein inactivation. Combining these techniques with rheological measurements, we show that passive material properties of the cellularization-stage Drosophila embryo are essentially unaffected by myosin activity. These results suggest that this tissue is elastic, not predominantly viscous, on the developmentally relevant timescale.
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Affiliation(s)
- Amanda Nicole Goldner
- Department of Biophysics and Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Salena M. Fessehaye
- Department of Biophysics and Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Nataly Rodriguez
- Department of Biophysics and Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Kelly Ann Mapes
- Department of Biophysics and Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Miriam Osterfield
- Department of Biophysics and Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Konstantin Doubrovinski
- Department of Biophysics and Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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11
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Chen YCD, Chen YC, Rajesh R, Shoji N, Jacy M, Lacin H, Erclik T, Desplan C. Using single-cell RNA sequencing to generate predictive cell-type-specific split-GAL4 reagents throughout development. Proc Natl Acad Sci U S A 2023; 120:e2307451120. [PMID: 37523539 PMCID: PMC10410749 DOI: 10.1073/pnas.2307451120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 07/03/2023] [Indexed: 08/02/2023] Open
Abstract
Cell-type-specific tools facilitate the identification and functional characterization of the distinct cell types that form the complexity of neuronal circuits. A large collection of existing genetic tools in Drosophila relies on enhancer activity to label different subsets of cells and has been extremely useful in analyzing functional circuits in adults. However, these enhancer-based GAL4 lines often do not reflect the expression of nearby gene(s) as they only represent a small portion of the full gene regulatory elements. While genetic intersectional techniques such as the split-GAL4 system further improve cell-type-specificity, it requires significant time and resources to screen through combinations of enhancer expression patterns. Here, we use existing developmental single-cell RNA sequencing (scRNAseq) datasets to select gene pairs for split-GAL4 and provide a highly efficient and predictive pipeline (scMarco) to generate cell-type-specific split-GAL4 lines at any time during development, based on the native gene regulatory elements. These gene-specific split-GAL4 lines can be generated from a large collection of coding intronic MiMIC/CRIMIC lines or by CRISPR knock-in. We use the developing Drosophila visual system as a model to demonstrate the high predictive power of scRNAseq-guided gene-specific split-GAL4 lines in targeting known cell types, annotating clusters in scRNAseq datasets as well as in identifying novel cell types. Lastly, the gene-specific split-GAL4 lines are broadly applicable to any other Drosophila tissue. Our work opens new avenues for generating cell-type-specific tools for the targeted manipulation of distinct cell types throughout development and represents a valuable resource for the Drosophila community.
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Affiliation(s)
| | - Yen-Chung Chen
- Department of Biology, New York University, New York,NY10003
| | - Raghuvanshi Rajesh
- Department of Biology, New York University, New York,NY10003
- Center for Genomics and Systems Biology, New York University, Abu Dhabi51133, United Arab Emirates
| | - Nathalie Shoji
- Department of Biology, New York University, New York,NY10003
| | - Maisha Jacy
- Department of Biology, New York University, New York,NY10003
| | - Haluk Lacin
- Division of Biological and Biomedical Systems, University of Missouri - Kansas City, Kansas City, MO64110
| | - Ted Erclik
- Department of Biology and Cell, University of Toronto - Mississauga, Mississauga, ONL5L 1C6, Canada
- Department of Systems Biology, University of Toronto - Mississauga, Mississauga, ONL5L 1C6, Canada
| | - Claude Desplan
- Department of Biology, New York University, New York,NY10003
- Center for Genomics and Systems Biology, New York University, Abu Dhabi51133, United Arab Emirates
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12
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Aimino MA, Humenik J, Parisi MJ, Duhart JC, Mosca TJ. SynLight: a dicistronic strategy for simultaneous active zone and cell labeling in the Drosophila nervous system. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.17.549367. [PMID: 37502901 PMCID: PMC10370149 DOI: 10.1101/2023.07.17.549367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
At synapses, chemical neurotransmission mediates the exchange of information between neurons, leading to complex movement behaviors and stimulus processing. The immense number and variety of neurons within the nervous system makes discerning individual neuron populations difficult, necessitating the development of advanced neuronal labeling techniques. In Drosophila , Bruchpilot-Short and mCD8-GFP, which label presynaptic active zones and neuronal membranes, respectively, have been widely used to study synapse development and organization. This labeling is often achieved via expression of two independent constructs by a single binary expression system, but expression can weaken when multiple transgenes are expressed by a single driver. Ensuring adequate expression of each transgene is essential to enable more complex experiments; as such, work has sought to circumvent these drawbacks by developing methods that encode multiple proteins from a single transcript. Self-cleaving peptides, specifically 2A peptides, have emerged as effective sequences for accomplishing this task. We leveraged 2A ribosomal skipping peptides to engineer a construct that produces both Bruchpilot-Short and mCD8-GFP from the same mRNA, which we named SynLight. Using SynLight, we visualized the putative synaptic active zones and membranes of multiple classes of olfactory, visual, and motor neurons and observed correct separation of signal, confirming that both proteins are being generated separately. Furthermore, we demonstrate proof-of-principle by quantifying synaptic puncta number and neurite volume in olfactory neurons and finding no difference between the synapse densities of neurons expressing SynLight or neurons expressing both transgenes separately. At the neuromuscular junction, we determined that synaptic puncta number labeled by SynLight was comparable to endogenous puncta labeled by antibody staining. Overall, SynLight is a versatile tool for examining synapse density in any nervous system region of interest and allows new questions to be answered about synaptic development and organization.
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Affiliation(s)
- Michael A. Aimino
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107
| | - Jesse Humenik
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107
| | - Michael J. Parisi
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107
| | - Juan Carlos Duhart
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107
| | - Timothy J. Mosca
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107
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13
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Palumbo RJ, Hanes SD. Catalytic activity of the Bin3/MEPCE methyltransferase domain is dispensable for 7SK snRNP function in Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.01.543302. [PMID: 37333392 PMCID: PMC10274667 DOI: 10.1101/2023.06.01.543302] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Methylphosphate Capping Enzyme (MEPCE) monomethylates the gamma phosphate at the 5' end of the 7SK noncoding RNA, a modification thought to protect 7SK from degradation. 7SK serves as a scaffold for assembly of a snRNP complex that inhibits transcription by sequestering the positive elongation factor P-TEFb. While much is known about the biochemical activity of MEPCE in vitro, little is known about its functions in vivo, or what roles- if any-there are for regions outside the conserved methyltransferase domain. Here, we investigated the role of Bin3, the Drosophila ortholog of MEPCE, and its conserved functional domains in Drosophila development. We found that bin3 mutant females had strongly reduced rates of egg-laying, which was rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 promotes fecundity by repressing P-TEFb. bin3 mutants also exhibited neuromuscular defects, analogous to a patient with MEPCE haploinsufficiency. These defects were also rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 and MEPCE have conserved roles in promoting neuromuscular function by repressing P-TEFb. Unexpectedly, we found that a Bin3 catalytic mutant (Bin3Y795A) could still bind and stabilize 7SK and rescue all bin3 mutant phenotypes, indicating that Bin3 catalytic activity is dispensable for 7SK stability and snRNP function in vivo. Finally, we identified a metazoan-specific motif (MSM) outside of the methyltransferase domain and generated mutant flies lacking this motif (Bin3ΔMSM). Bin3ΔMSM mutant flies exhibited some-but not all-bin3 mutant phenotypes, suggesting that the MSM is required for a 7SK-independent, tissue-specific function of Bin3.
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Affiliation(s)
- Ryan J Palumbo
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University 750 East Adams Street, 4283 Weiskotten Hall, Syracuse, New York, 13210
| | - Steven D Hanes
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University 750 East Adams Street, 4283 Weiskotten Hall, Syracuse, New York, 13210
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14
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Teague AG, Quintero M, Karimi Dermani F, Cagan RL, Bangi E. A polycistronic transgene design for combinatorial genetic perturbations from a single transcript in Drosophila. PLoS Genet 2023; 19:e1010792. [PMID: 37267433 DOI: 10.1371/journal.pgen.1010792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 05/18/2023] [Indexed: 06/04/2023] Open
Abstract
Experimental models that capture the genetic complexity of human disease and allow mechanistic explorations of the underlying cell, tissue, and organ interactions are crucial to furthering our understanding of disease biology. Such models require combinatorial manipulations of multiple genes, often in more than one tissue at once. The ability to perform complex genetic manipulations in vivo is a key strength of Drosophila, where many tools for sophisticated and orthogonal genetic perturbations exist. However, combining the large number of transgenes required to establish more representative disease models and conducting mechanistic studies in these already complex genetic backgrounds is challenging. Here we present a design that pushes the limits of Drosophila genetics by allowing targeted combinatorial ectopic expression and knockdown of multiple genes from a single inducible transgene. The polycistronic transcript encoded by this transgene includes a synthetic short hairpin cluster cloned within an intron placed at the 5' end of the transcript, followed by two protein-coding sequences separated by the T2A sequence that mediates ribosome skipping. This technology is particularly useful for modeling genetically complex diseases like cancer, which typically involve concurrent activation of multiple oncogenes and loss of multiple tumor suppressors. Furthermore, consolidating multiple genetic perturbations into a single transgene further streamlines the ability to perform combinatorial genetic manipulations and makes it readily adaptable to a broad palette of transgenic systems. This flexible design for combinatorial genetic perturbations will also be a valuable tool for functionally exploring multigenic gene signatures identified from omics studies of human disease and creating humanized Drosophila models to characterize disease-associated variants in human genes. It can also be adapted for studying biological processes underlying normal tissue homeostasis and development that require simultaneous manipulation of many genes.
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Affiliation(s)
- Alexander G Teague
- Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
| | - Maria Quintero
- Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
| | - Fateme Karimi Dermani
- Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
| | - Ross L Cagan
- Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
| | - Erdem Bangi
- Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
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15
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Genetics tools for corpora allata specific gene expression in Aedes aegypti mosquitoes. Sci Rep 2022; 12:20426. [PMID: 36443489 PMCID: PMC9705396 DOI: 10.1038/s41598-022-25009-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
Juvenile hormone (JH) is synthesized by the corpora allata (CA) and controls development and reproduction in insects. Therefore, achieving tissue-specific expression of transgenes in the CA would be beneficial for mosquito research and control. Different CA promoters have been used to drive transgene expression in Drosophila, but mosquito CA-specific promoters have not been identified. Using the CRISPR/Cas9 system, we integrated transgenes encoding the reporter green fluorescent protein (GFP) close to the transcription start site of juvenile hormone acid methyl transferase (JHAMT), a locus encoding a JH biosynthetic enzyme, specifically and highly expressed in the CA of Aedes aegypti mosquitoes. Transgenic individuals showed specific GFP expression in the CA but failed to reproduce the full pattern of jhamt spatiotemporal expression. In addition, we created GeneSwitch driver and responder mosquito lines expressing an inducible fluorescent marker, enabling the temporal regulation of the transgene via the presence or absence of an inducer drug. The use of the GeneSwitch system has not previously been reported in mosquitoes and provides a new inducible binary system that can control transgene expression in Aedes aegypti.
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16
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Huang Y, Lemire G, Briere LC, Liu F, Wessels MW, Wang X, Osmond M, Kanca O, Lu S, High FA, Walker MA, Rodan LH, Kernohan KD, Sweetser DA, Boycott KM, Bellen HJ. The recurrent de novo c.2011C>T missense variant in MTSS2 causes syndromic intellectual disability. Am J Hum Genet 2022; 109:1923-1931. [PMID: 36067766 PMCID: PMC9606386 DOI: 10.1016/j.ajhg.2022.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/12/2022] [Indexed: 01/25/2023] Open
Abstract
MTSS2, also known as MTSS1L, binds to plasma membranes and modulates their bending. MTSS2 is highly expressed in the central nervous system (CNS) and appears to be involved in activity-dependent synaptic plasticity. Variants in MTSS2 have not yet been associated with a human phenotype in OMIM. Here we report five individuals with the same heterozygous de novo variant in MTSS2 (GenBank: NM_138383.2: c.2011C>T [p.Arg671Trp]) identified by exome sequencing. The individuals present with global developmental delay, mild intellectual disability, ophthalmological anomalies, microcephaly or relative microcephaly, and shared mild facial dysmorphisms. Immunoblots of fibroblasts from two affected individuals revealed that the variant does not significantly alter MTSS2 levels. We modeled the variant in Drosophila and showed that the fly ortholog missing-in-metastasis (mim) was widely expressed in most neurons and a subset of glia of the CNS. Loss of mim led to a reduction in lifespan, impaired locomotor behavior, and reduced synaptic transmission in adult flies. Expression of the human MTSS2 reference cDNA rescued the mim loss-of-function (LoF) phenotypes, whereas the c.2011C>T variant had decreased rescue ability compared to the reference, suggesting it is a partial LoF allele. However, elevated expression of the variant, but not the reference MTSS2 cDNA, led to similar defects as observed by mim LoF, suggesting that the variant is toxic and may act as a dominant-negative allele when expressed in flies. In summary, our findings support that mim is important for appropriate neural function, and that the MTSS2 c.2011C>T variant causes a syndromic form of intellectual disability.
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Affiliation(s)
- Yan Huang
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Gabrielle Lemire
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada; Broad Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Lauren C Briere
- Division of Medical Genetics & Metabolism, Massachusetts General Hospital for Children, Boston, MA 02114, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Fang Liu
- Department of Pediatrics, Bethune International Peace Hospital, Shijiazhuang 050082, Hebei, China
| | - Marja W Wessels
- Department of Clinical Genetics, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Xueqi Wang
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Matthew Osmond
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Shenzhao Lu
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Frances A High
- Division of Medical Genetics & Metabolism, Massachusetts General Hospital for Children, Boston, MA 02114, USA
| | - Melissa A Walker
- Department of Neurology, Division of Neurogenetics, Child Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Lance H Rodan
- Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Kristin D Kernohan
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada; Newborn Screening Ontario, Children's Hospital of Eastern Ontario, Ottawa, ON K1H 8L1, Canada
| | - David A Sweetser
- Division of Medical Genetics & Metabolism, Massachusetts General Hospital for Children, Boston, MA 02114, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Kym M Boycott
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
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17
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Wang L, Lin G, Zuo Z, Li Y, Byeon SK, Pandey A, Bellen HJ. Neuronal activity induces glucosylceramide that is secreted via exosomes for lysosomal degradation in glia. SCIENCE ADVANCES 2022; 8:eabn3326. [PMID: 35857503 PMCID: PMC9278864 DOI: 10.1126/sciadv.abn3326] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Recessive variants in GBA1 cause Gaucher disease, a prevalent form of lysosome storage disease. GBA1 encodes a lysosomal enzyme that hydrolyzes glucosylceramide (GlcCer) into glucose and ceramide. Its loss causes lysosomal dysfunction and increased levels of GlcCer. We generated a null allele of the Drosophila ortholog Gba1b by inserting the Gal4 using CRISPR-Cas9. Here, we show that Gba1b is expressed in glia but not in neurons. Glial-specific knockdown recapitulates the defects found in Gba1b mutants, and these can be rescued by glial expression of human GBA1. We show that GlcCer is synthesized upon neuronal activity, and it is transported from neurons to glia through exosomes. Furthermore, we found that glial TGF-β/BMP induces the transfer of GlcCer from neurons to glia and that the White protein, an ABCG transporter, promotes GlcCer trafficking to glial lysosomes for degradation.
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Affiliation(s)
- Liping Wang
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030, USA
| | - Guang Lin
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zhongyuan Zuo
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yarong Li
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Seul Kee Byeon
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
| | - Akhilesh Pandey
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA
- Manipal Academy of Higher Education, Manipal, Karnataka 576 104, India
| | - Hugo J. Bellen
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Corresponding author.
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18
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Damage-responsive neuro-glial clusters coordinate the recruitment of dormant neural stem cells in Drosophila. Dev Cell 2022; 57:1661-1675.e7. [PMID: 35716661 DOI: 10.1016/j.devcel.2022.05.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/31/2022] [Accepted: 05/18/2022] [Indexed: 11/23/2022]
Abstract
Recruitment of stem cells is crucial for tissue repair. Although stem cell niches can provide important signals, little is known about mechanisms that coordinate the engagement of disseminated stem cells across an injured tissue. In Drosophila, adult brain lesions trigger local recruitment of scattered dormant neural stem cells suggesting a mechanism for creating a transient stem cell activation zone. Here, we find that injury triggers a coordinated response in neuro-glial clusters that promotes the spread of a neuron-derived stem cell factor via glial secretion of the lipocalin-like transporter Swim. Strikingly, swim is induced in a Hif1-α-dependent manner in response to brain hypoxia. Mammalian Swim (Lcn7) is also upregulated in glia of the mouse hippocampus upon brain injury. Our results identify a central role of neuro-glial clusters in promoting neural stem cell activation at a distance, suggesting a conserved function of the HIF1-α/Swim/Wnt module in connecting injury-sensing and regenerative outcomes.
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19
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Ye Z, Liu F, Sun H, Ferguson ST, Baker A, Ochieng SA, Zwiebel LJ. Discrete roles of Ir76b ionotropic coreceptor impact olfaction, blood feeding, and mating in the malaria vector mosquito Anopheles coluzzii. Proc Natl Acad Sci U S A 2022; 119:e2112385119. [PMID: 35648836 PMCID: PMC9191353 DOI: 10.1073/pnas.2112385119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 04/13/2022] [Indexed: 11/18/2022] Open
Abstract
Anopheline mosquitoes rely on their highly sensitive chemosensory apparatus to detect diverse chemical stimuli that drive the host-seeking and blood-feeding behaviors required to vector pathogens for malaria and other diseases. This process incorporates a variety of chemosensory receptors and transduction pathways. We used advanced in vivo gene-editing and -labeling approaches to localize and functionally characterize the ionotropic coreceptor AcIr76b in the malaria mosquito Anopheles coluzzii, where it impacts both olfactory and gustatory systems. AcIr76b has a broad expression pattern in female adult antennal grooved pegs, coeloconic sensilla, and T1 and T2 sensilla on the labellum, stylets, and tarsi, as well as the larval sensory peg. AcIr76b is colocalized with the Orco odorant receptor (OR) coreceptor in a subset of cells across the female antennae and labella. In contrast to Orco and Ir8a, chemosensory coreceptors that appear essential for the activity of their respective sets of chemosensory neurons in mosquitoes, AcIr76b−/− mutants maintain wild-type peripheral responses to volatile amines on the adult palps, labellum, and larval sensory cone. Interestingly, AcIr76b−/− mutants display significantly increased responses to amines in antennal grooved peg sensilla, while coeloconic sensilla reveal significant deficits in responses to several acids and amines. Behaviorally, AcIr76b mutants manifest significantly female-specific insemination deficits, and although AcIr76b−/− mutant females can locate, alight on, and probe artificial blood hosts, they are incapable of blood feeding successfully. Taken together, our findings reveal a multidimensional functionality of Ir76b in anopheline olfactory and gustatory pathways that directly impacts the vectorial capacity of these mosquitoes.
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Affiliation(s)
- Zi Ye
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Feng Liu
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Huahua Sun
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Stephen T. Ferguson
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Adam Baker
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Samuel A. Ochieng
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Laurence J. Zwiebel
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
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20
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Task D, Lin CC, Vulpe A, Afify A, Ballou S, Brbic M, Schlegel P, Raji J, Jefferis GSXE, Li H, Menuz K, Potter CJ. Chemoreceptor co-expression in Drosophila melanogaster olfactory neurons. eLife 2022; 11:e72599. [PMID: 35442190 PMCID: PMC9020824 DOI: 10.7554/elife.72599] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 03/07/2022] [Indexed: 12/20/2022] Open
Abstract
Drosophila melanogaster olfactory neurons have long been thought to express only one chemosensory receptor gene family. There are two main olfactory receptor gene families in Drosophila, the odorant receptors (ORs) and the ionotropic receptors (IRs). The dozens of odorant-binding receptors in each family require at least one co-receptor gene in order to function: Orco for ORs, and Ir25a, Ir8a, and Ir76b for IRs. Using a new genetic knock-in strategy, we targeted the four co-receptors representing the main chemosensory families in D. melanogaster (Orco, Ir8a, Ir76b, Ir25a). Co-receptor knock-in expression patterns were verified as accurate representations of endogenous expression. We find extensive overlap in expression among the different co-receptors. As defined by innervation into antennal lobe glomeruli, Ir25a is broadly expressed in 88% of all olfactory sensory neuron classes and is co-expressed in 82% of Orco+ neuron classes, including all neuron classes in the maxillary palp. Orco, Ir8a, and Ir76b expression patterns are also more expansive than previously assumed. Single sensillum recordings from Orco-expressing Ir25a mutant antennal and palpal neurons identify changes in olfactory responses. We also find co-expression of Orco and Ir25a in Drosophila sechellia and Anopheles coluzzii olfactory neurons. These results suggest that co-expression of chemosensory receptors is common in insect olfactory neurons. Together, our data present the first comprehensive map of chemosensory co-receptor expression and reveal their unexpected widespread co-expression in the fly olfactory system.
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Affiliation(s)
- Darya Task
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Chun-Chieh Lin
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
- Mortimer B. Zuckermann Mind Brain Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Alina Vulpe
- Physiology & Neurobiology Department, University of ConnecticutMansfieldUnited States
| | - Ali Afify
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Sydney Ballou
- Physiology & Neurobiology Department, University of ConnecticutMansfieldUnited States
| | - Maria Brbic
- Department of Computer Science, Stanford UniversityStanfordUnited States
| | - Philipp Schlegel
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Joshua Raji
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Gregory SXE Jefferis
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Hongjie Li
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Karen Menuz
- Physiology & Neurobiology Department, University of ConnecticutMansfieldUnited States
| | - Christopher J Potter
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
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21
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Lu S, Hernan R, Marcogliese PC, Huang Y, Gertler TS, Akcaboy M, Liu S, Chung HL, Pan X, Sun X, Oguz MM, Oztoprak U, de Baaij JH, Ivanisevic J, McGinnis E, Guillen Sacoto MJ, Chung WK, Bellen HJ. Loss-of-function variants in TIAM1 are associated with developmental delay, intellectual disability, and seizures. Am J Hum Genet 2022; 109:571-586. [PMID: 35240055 DOI: 10.1016/j.ajhg.2022.01.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/27/2022] [Indexed: 12/13/2022] Open
Abstract
TIAM Rac1-associated GEF 1 (TIAM1) regulates RAC1 signaling pathways that affect the control of neuronal morphogenesis and neurite outgrowth by modulating the actin cytoskeletal network. To date, TIAM1 has not been associated with a Mendelian disorder. Here, we describe five individuals with bi-allelic TIAM1 missense variants who have developmental delay, intellectual disability, speech delay, and seizures. Bioinformatic analyses demonstrate that these variants are rare and likely pathogenic. We found that the Drosophila ortholog of TIAM1, still life (sif), is expressed in larval and adult central nervous system (CNS) and is mainly expressed in a subset of neurons, but not in glia. Loss of sif reduces the survival rate, and the surviving adults exhibit climbing defects, are prone to severe seizures, and have a short lifespan. The TIAM1 reference (Ref) cDNA partially rescues the sif loss-of-function (LoF) phenotypes. We also assessed the function associated with three TIAM1 variants carried by two of the probands and compared them to the TIAM1 Ref cDNA function in vivo. TIAM1 p.Arg23Cys has reduced rescue ability when compared to TIAM1 Ref, suggesting that it is a partial LoF variant. In ectopic expression studies, both wild-type sif and TIAM1 Ref are toxic, whereas the three variants (p.Leu862Phe, p.Arg23Cys, and p.Gly328Val) show reduced toxicity, suggesting that they are partial LoF variants. In summary, we provide evidence that sif is important for appropriate neural function and that TIAM1 variants observed in the probands are disruptive, thus implicating loss of TIAM1 in neurological phenotypes in humans.
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22
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Sun L, Zhang C, Yan L, Wang X, Wang Z, Cao C. Bursicon receptor gene HLGR2 as a potential RNA interference target for control of the fall webworm Hyphantria cunea. PEST MANAGEMENT SCIENCE 2022; 78:1492-1499. [PMID: 34962063 DOI: 10.1002/ps.6767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 12/22/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Insect G protein-coupled receptors (GPCRs) have been identified as a new generation of attractive targets for RNA interference (RNAi)-based pest control. A functional study of the leucine-rich repeat-containing (LGR2) gene in Hyphantria cunea (HLGR2) was performed to examine whether it can be used in the molecular control of this notorious pest. RESULTS The complementary DNA (cDNA) sequence and deduced amino acids of HLGR2 were obtained and analyzed in the present study. HLGR2 is a typical GPCR and shows high structural and sequence similarity with other insect LGR2 proteins. The spatiotemporal expression profiles of HLGR2 showed that HLGR2 was highly expressed at the egg stage and tissues of head and silk gland. After RNAi of HLGR2, distinct phenotypes were observed when HLGR2 expression was suppressed, indicating that HLGR2 is essential in pupation and eclosion. HLGR2 RNAi led to a low pupation rate (45.00%), body malformation, abnormal wing expansion, failed cuticle melanization (63.33%), and high mortality rate (48.33%). Furthermore, we identified eight genes that are regulated by HLGR2. The expression of these eight genes was induced by the HLGR2 signaling pathway and correlated well with cuticle sclerotization. Unlike LGR2 in other insect species, HLGR2 was found to play a crucial role in the control of H. cunea during ecdysis and postecdysial stages. CONCLUSION HLGR2 is essential for the growth and development and wing expansion and maturation in H. cunea, suggesting HLGR2 is a promising candidate for application in RNAi-based control of this notorious agriculture-forest pest. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Lili Sun
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin, P. R. China
| | - Chenshu Zhang
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin, P. R. China
| | - Liqiong Yan
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin, P. R. China
| | - Xiaoqi Wang
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin, P. R. China
| | - Zhiying Wang
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin, P. R. China
| | - Chuanwang Cao
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin, P. R. China
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23
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The CinB Nuclease from wNo Wolbachia Is Sufficient for Induction of Cytoplasmic Incompatibility in Drosophila. mBio 2022; 13:e0317721. [PMID: 35073749 PMCID: PMC8787490 DOI: 10.1128/mbio.03177-21] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Wolbachia is an obligate intracellular bacterium that can alter reproduction of its arthropod hosts, often through a mechanism called cytoplasmic incompatibility (CI). In CI, uninfected females fertilized by infected males yield few offspring, but if both are similarly infected, normal embryo viability results (called "rescue"). CI factors (Cifs) responsible for CI are pairs of proteins encoded by linked genes. The downstream gene in each pair encodes either a deubiquitylase (CidB) or a nuclease (CinB). The upstream gene products, CidA and CinA, bind their cognate enzymes with high specificity. Expression of CidB or CinB in yeast inhibits growth, but growth is rescued by expression of the cognate CifA protein. By contrast, transgenic Drosophila male germ line expression of both cifA and cifB was reported to be necessary to induce CI-like embryonic arrest; cifA expression alone in females is sufficient for rescue. This pattern, seen with genes from several Wolbachia strains, has been called the "2-by-1" model. Here, we show that male germ line expression of the cinB gene alone, from a distinct clade of cif genes from wNo Wolbachia, is sufficient to induce nearly complete loss of embryo viability. This male sterility is fully rescued by cognate cinAwNo expression in the female germ line. The proteins behave similarly in yeast. CinBwNo toxicity depends on its nuclease active site. These results demonstrate that highly divergent CinB nucleases can induce CI, that rescue by cognate CifA factors is a general feature of Wolbachia CI systems, and that CifA is not strictly required in males for CI induction. IMPORTANCE Wolbachia bacteria live within the cells of many insects. Like mitochondria, they are only inherited from females. Wolbachia often increases the number of infected females to promote spread of infection using a type of male sterility called cytoplasmic incompatibility (CI): when uninfected females mate with infected males, most embryos die; if both are similarly infected, embryos develop normally, giving infected females an advantage in producing offspring. CI is being used against disease-carrying mosquitoes and agricultural pests. Wolbachia proteins called CifA and CifB, which bind one another, cause CI, but how they work has been unclear. Here, we show that a CifB protein singly produced in fruit fly males causes sterility in crosses to normal females, but this is rescued if the females produce the CifA partner. These findings clarify a broad range of observations on CI and will allow more rational approaches to using it for insect control.
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24
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Horard B, Terretaz K, Gosselin-Grenet AS, Sobry H, Sicard M, Landmann F, Loppin B. Paternal transmission of the Wolbachia CidB toxin underlies cytoplasmic incompatibility. Curr Biol 2022; 32:1319-1331.e5. [DOI: 10.1016/j.cub.2022.01.052] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/18/2021] [Accepted: 01/19/2022] [Indexed: 02/09/2023]
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25
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Li Z, You L, Zhang Q, Yu Y, Tan A. A Targeted In-Fusion Expression System for Recombinant Protein Production in Bombyx mori. Front Genet 2022; 12:816075. [PMID: 35058975 PMCID: PMC8763709 DOI: 10.3389/fgene.2021.816075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 11/30/2021] [Indexed: 11/25/2022] Open
Abstract
The domesticated silkworm, Bombyx mori, is an economically important insect that synthesizes large amounts of silk proteins in its silk gland to make cocoons. In recent years, germline transformation strategies advanced the bioengineering of the silk gland as an ideal bioreactor for mass production of recombinant proteins. However, the yield of exogenous proteins varied largely due to the random insertion and gene drift caused by canonical transposon-based transformation, calling for site-specific and stable expression systems. In the current study, we established a targeted in-fusion expression system by using the transcription activator-like effector nuclease (TALEN)-mediated targeted insertion to target genomic locus of sericin, one of the major silk proteins. We successfully generated chimeric Sericin1-EGFP (Ser-2A-EGFP) transformant, producing up to 3.1% (w/w) of EGFP protein in the cocoon shell. With this strategy, we further expressed the medically important human epidermal growth factor (hEGF) and the protein yield in both middle silk glands, and cocoon shells reached to more than 15-fold higher than the canonical piggyBac-based transgenesis. This natural Sericin1 expression system provides a new strategy for producing recombinant proteins by using the silkworm silk gland as the bioreactor.
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Affiliation(s)
- Zhiqian Li
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China.,Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Lang You
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Qichao Zhang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Ye Yu
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Anjiang Tan
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
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26
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Fölsz O, Lin CC, Task D, Riabinina O, Potter CJ. The Q-system: A Versatile Repressible Binary Expression System. Methods Mol Biol 2022; 2540:35-78. [PMID: 35980572 DOI: 10.1007/978-1-0716-2541-5_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Binary expression systems are useful genetic tools for experimentally labeling or manipulating the function of defined cells. The Q-system is a repressible binary expression system that consists of a transcription factor QF (and the recently improved QF2/QF2w), the inhibitor QS, a QUAS-geneX effector, and a drug that inhibits QS (quinic acid). The Q-system can be used alone or in combination with other binary expression systems, such as GAL4/UAS and LexA/LexAop. In this review chapter, we discuss the past, present, and future of the Q-system for applications in Drosophila and other organisms. We discuss the in vivo application of the Q-system for transgenic labeling, the modular nature of QF that allows chimeric or split transcriptional activators to be developed, its temporal control by quinic acid, new methods to generate QF2 reagents, intersectional expression labeling, and its recent adoption into many emerging experimental species.
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Affiliation(s)
- Orsolya Fölsz
- Department of Biosciences, Durham University, Durham, UK
| | - Chun-Chieh Lin
- Department of Pathology and Laboratory Medicine, Giesel School of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | - Darya Task
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | | | - Christopher J Potter
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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27
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Abstract
CRISPR-mediated genome engineering technologies have been adapted to a wide variety of organisms with high efficiency and specificity. The yellow fever mosquito, Aedes aegypti , is one such organism. It is also responsible for transmitting a wide variety of deadly viruses including Dengue, Zika, Yellow fever, and Chikungunya. The key to successful CRISPR-mediated gene editing applications is the delivery of both Cas9 ribonuclease and single-guide RNA (sgRNA ) to the nucleus of desired cells. Various methods have been developed for supplying the Cas9 endonuclease, sgRNA , and donor DNA to Ae. aegypti. In this chapter, we focus on methods of direct embryo delivery of editing components, presenting detailed step-by-step CRISPR/Cas9-based genome-editing protocols for inducing desired heritable edits in mosquitoes as well as insights into successful application of these protocols. We also highlight potential opportunities for customizing these protocols to manipulate the mosquito genome for innovative in vivo gene function studies.
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Affiliation(s)
- Ruichen Sun
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Ming Li
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Conor J McMeniman
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Omar S Akbari
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA.
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28
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Chen J, Luo J, Gurav AS, Chen Z, Wang Y, Montell C. A DREaMR system to simplify combining mutations with rescue transgenes in Aedes aegypti. Genetics 2021; 219:6368066. [PMID: 34740249 DOI: 10.1093/genetics/iyab146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/01/2021] [Indexed: 11/14/2022] Open
Abstract
In most experimental animals, it is challenging to combine mutations and rescue transgenes and to use bipartite systems to assess gene expression. To circumvent the difficulties in combining multiple genetic elements, we developed the DREaMR (Drug-on, REporter, Mutant, Rescue) system. Using Drosophila white as the initial model, we demonstrated that introduction of a single insertion by CRISPR/Cas9 created a null mutation, a tagged rescue construct, which could be induced with doxycycline, and which allowed assessment of protein expression. To create a DREaMR in an organism in which combining multiple genetic elements is more problematic than in Drosophila, we tested the mosquito, Aedes aegypti-the insect vector for dengue, yellow fever, Zika, and other viral diseases. We generated a DREaMR allele in the kh gene, which permitted us to induce expression of the rescue construct, and detect expression of Kh. Thus, this system avoids the need to perform genetic crosses to introduce an inducible rescue transgene in a mutant background, or to combine driver and reporter lines to examine expression of the targeted protein. We propose that DREaMR provides a system that can be applied to additional mosquito vectors as well as other organisms in which CRISPR/Cas9 is effective.
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Affiliation(s)
- Jieyan Chen
- Department of Molecular, Cellular, and Developmental Biology and the Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Junjie Luo
- Department of Molecular, Cellular, and Developmental Biology and the Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Adishthi S Gurav
- Department of Molecular, Cellular, and Developmental Biology and the Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Zijing Chen
- Department of Molecular, Cellular, and Developmental Biology and the Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | | | - Craig Montell
- Department of Molecular, Cellular, and Developmental Biology and the Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
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29
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Slo2/K Na Channels in Drosophila Protect against Spontaneous and Induced Seizure-like Behavior Associated with an Increased Persistent Na + Current. J Neurosci 2021; 41:9047-9063. [PMID: 34544836 DOI: 10.1523/jneurosci.0290-21.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/20/2021] [Accepted: 09/13/2021] [Indexed: 11/21/2022] Open
Abstract
Na+ sensitivity is a unique feature of Na+-activated K+ (KNa) channels, making them naturally suited to counter a sudden influx in Na+ ions. As such, it has long been suggested that KNa channels may serve a protective function against excessive excitation associated with neuronal injury and disease. This hypothesis, however, has remained largely untested. Here, we examine KNa channels encoded by the Drosophila Slo2 (dSlo2) gene in males and females. We show that dSlo2/KNa channels are selectively expressed in cholinergic neurons in the adult brain, as well as in glutamatergic motor neurons, where dampening excitation may function to inhibit global hyperactivity and seizure-like behavior. Indeed, we show that effects of feeding Drosophila a cholinergic agonist are exacerbated by the loss of dSlo2/KNa channels. Similar to mammalian Slo2/KNa channels, we show that dSlo2/KNa channels encode a TTX-sensitive K+ conductance, indicating that dSlo2/KNa channels can be activated by Na+ carried by voltage-dependent Na+ channels. We then tested the role of dSlo2/KNa channels in established genetic seizure models in which the voltage-dependent persistent Na+ current (INap) is elevated. We show that the absence of dSlo2/KNa channels increased susceptibility to mechanically induced seizure-like behavior. Similar results were observed in WT flies treated with veratridine, an enhancer of INap Finally, we show that loss of dSlo2/KNa channels in both genetic and pharmacologically primed seizure models resulted in the appearance of spontaneous seizures. Together, our results support a model in which dSlo2/KNa channels, activated by neuronal overexcitation, contribute to a protective threshold to suppress the induction of seizure-like activity.SIGNIFICANCE STATEMENT Slo2/KNa channels are unique in that they constitute a repolarizing K+ pore that is activated by the depolarizing Na+ ion, making them naturally suited to function as a protective "brake" against overexcitation and Na+ overload. Here, we test this hypothesis in vivo by examining how a null mutation of the Drosophila Slo2 (dSlo2)/KNa gene affects seizure-like behavior in genetic and pharmacological models of epilepsy. We show that indeed the loss of dSlo2/KNa channels results in increased incidence and severity of induced seizure behavior, as well as the appearance of spontaneous seizure activity. Our results advance our understanding of neuronal excitability and protective mechanisms that preserve normal physiology and the suppression of seizure susceptibility.
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30
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Structural and mechanistic insights into the complexes formed by Wolbachia cytoplasmic incompatibility factors. Proc Natl Acad Sci U S A 2021; 118:2107699118. [PMID: 34620712 DOI: 10.1073/pnas.2107699118] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2021] [Indexed: 11/18/2022] Open
Abstract
Wolbachia bacteria, inherited through the female germ line, infect a large fraction of arthropod species. Many Wolbachia strains manipulate host reproduction, most commonly through cytoplasmic incompatibility (CI). CI, a conditional male sterility, results when Wolbachia-infected male insects mate with uninfected females; viability is restored if the female is similarly infected (called "rescue"). CI is used to help control mosquito-borne viruses such as dengue and Zika, but its mechanisms remain unknown. The coexpressed CI factors CifA and CifB form stable complexes in vitro, but the timing and function of this interaction in the insect are unresolved. CifA expression in the female germ line is sufficient for rescue. We report high-resolution structures of a CI-factor complex, CinA-CinB, which utilizes a unique binding mode between the CinA rescue factor and the CinB nuclease; the structures were validated by biochemical and yeast growth analyses. Importantly, transgenic expression in Drosophila of a nonbinding CinA mutant, designed based on the CinA-CinB structure, suggests CinA expressed in females must bind CinB imported by sperm in order to rescue embryonic viability. Binding between cognate factors is conserved in an enzymatically distinct CI system, CidA-CidB, suggesting universal features in Wolbachia CI induction and rescue.
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31
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Beckmann JF, Van Vaerenberghe K, Akwa DE, Cooper BS. A single mutation weakens symbiont-induced reproductive manipulation through reductions in deubiquitylation efficiency. Proc Natl Acad Sci U S A 2021; 118:e2113271118. [PMID: 34548405 PMCID: PMC8488622 DOI: 10.1073/pnas.2113271118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 11/18/2022] Open
Abstract
Animals interact with microbes that affect their performance and fitness, including endosymbionts that reside inside their cells. Maternally transmitted Wolbachia bacteria are the most common known endosymbionts, in large part because of their manipulation of host reproduction. For example, many Wolbachia cause cytoplasmic incompatibility (CI) that reduces host embryonic viability when Wolbachia-modified sperm fertilize uninfected eggs. Operons termed cifs control CI, and a single factor (cifA) rescues it, providing Wolbachia-infected females a fitness advantage. Despite CI's prevalence in nature, theory indicates that natural selection does not act to maintain CI, which varies widely in strength. Here, we investigate the genetic and functional basis of CI-strength variation observed among sister Wolbachia that infect Drosophila melanogaster subgroup hosts. We cloned, Sanger sequenced, and expressed cif repertoires from weak CI-causing wYak in Drosophila yakuba, revealing mutations suspected to weaken CI relative to model wMel in D. melanogaster A single valine-to-leucine mutation within the deubiquitylating (DUB) domain of the wYak cifB homolog (cidB) ablates a CI-like phenotype in yeast. The same mutation reduces both DUB efficiency in vitro and transgenic CI strength in the fly, each by about twofold. Our results map hypomorphic transgenic CI to reduced DUB activity and indicate that deubiquitylation is central to CI induction in cid systems. We also characterize effects of other genetic variation distinguishing wMel-like cifs Importantly, CI strength determines Wolbachia prevalence in natural systems and directly influences the efficacy of Wolbachia biocontrol strategies in transinfected mosquito systems. These approaches rely on strong CI to reduce human disease.
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Affiliation(s)
- John F Beckmann
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849;
| | | | - Daniel E Akwa
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849
| | - Brandon S Cooper
- Division of Biological Sciences, University of Montana, Missoula, MT 59801
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32
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Christesen D, Yang YT, Chen W, Batterham P, Perry T. Loss of the Dβ1 nicotinic acetylcholine receptor subunit disrupts bursicon-driven wing expansion and diminishes adult viability in Drosophila melanogaster. Genetics 2021; 219:iyab112. [PMID: 34849910 PMCID: PMC8633089 DOI: 10.1093/genetics/iyab112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 07/03/2021] [Indexed: 01/15/2023] Open
Abstract
Cholinergic signaling dominates the insect central nervous system, contributing to numerous fundamental pathways and behavioral circuits. However, we are only just beginning to uncover the diverse roles different cholinergic receptors may play. Historically, insect nicotinic acetylcholine receptors have received attention due to several subunits being key insecticide targets. More recently, there has been a focus on teasing apart the roles of these receptors, and their constituent subunits, in native signaling pathways. In this study, we use CRISPR-Cas9 genome editing to generate germline and somatic deletions of the Dβ1 nicotinic acetylcholine receptor subunit and investigate the consequences of loss of function in Drosophila melanogaster. Severe impacts on movement, male courtship, longevity, and wing expansion were found. Loss of Dβ1 was also associated with a reduction in transcript levels for the wing expansion hormone bursicon. Neuron-specific somatic deletion of Dβ1 in bursicon-producing neurons (CCAP-GAL4) was sufficient to disrupt wing expansion. Furthermore, CCAP-GAL4-specific expression of Dβ1 in a germline deletion background was sufficient to rescue the wing phenotype, pinpointing CCAP neurons as the neuronal subset requiring Dβ1 for the wing expansion pathway. Dβ1 is a known target of multiple commercially important insecticides, and the fitness costs exposed here explain why field-isolated target-site resistance has only been reported for amino acid replacements and not loss of function. This work reveals the importance of Dβ1-containing nicotinic acetylcholine receptors in CCAP neurons for robust bursicon-driven wing expansion.
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Affiliation(s)
- Danielle Christesen
- School of Biosciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Ying Ting Yang
- School of Biosciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Wei Chen
- School of Biosciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Philip Batterham
- School of Biosciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Trent Perry
- School of Biosciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
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33
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Yoshinari Y, Kosakamoto H, Kamiyama T, Hoshino R, Matsuoka R, Kondo S, Tanimoto H, Nakamura A, Obata F, Niwa R. The sugar-responsive enteroendocrine neuropeptide F regulates lipid metabolism through glucagon-like and insulin-like hormones in Drosophila melanogaster. Nat Commun 2021; 12:4818. [PMID: 34376687 PMCID: PMC8355161 DOI: 10.1038/s41467-021-25146-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 07/24/2021] [Indexed: 02/08/2023] Open
Abstract
The enteroendocrine cell (EEC)-derived incretins play a pivotal role in regulating the secretion of glucagon and insulins in mammals. Although glucagon-like and insulin-like hormones have been found across animal phyla, incretin-like EEC-derived hormones have not yet been characterised in invertebrates. Here, we show that the midgut-derived hormone, neuropeptide F (NPF), acts as the sugar-responsive, incretin-like hormone in the fruit fly, Drosophila melanogaster. Secreted NPF is received by NPF receptor in the corpora cardiaca and in insulin-producing cells. NPF-NPFR signalling resulted in the suppression of the glucagon-like hormone production and the enhancement of the insulin-like peptide secretion, eventually promoting lipid anabolism. Similar to the loss of incretin function in mammals, loss of midgut NPF led to significant metabolic dysfunction, accompanied by lipodystrophy, hyperphagia, and hypoglycaemia. These results suggest that enteroendocrine hormones regulate sugar-dependent metabolism through glucagon-like and insulin-like hormones not only in mammals but also in insects.
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Affiliation(s)
- Yuto Yoshinari
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki, Japan
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Hina Kosakamoto
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory for Nutritional Biology, RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo, Japan
| | - Takumi Kamiyama
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Ryo Hoshino
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Rena Matsuoka
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Shu Kondo
- Genetic Strains Research Center, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Hiromu Tanimoto
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Akira Nakamura
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
- Laboratory of Germline Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Fumiaki Obata
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki, Japan
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory for Nutritional Biology, RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo, Japan
- Laboratory of Molecular Cell Biology and Development, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- AMED-PRIME, Japan Agency for Medical Research and Development Chiyoda-ku, Tokyo, Japan
| | - Ryusuke Niwa
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki, Japan.
- AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo, Japan.
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34
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Abstract
The ability to express a gene in all neurons is a crucial tool for studying the nervous system. Zhao et al., 2021 unlock genetic access to all neurons in mosquitoes by generating the first pan-neuronal transgenes in this non-model insect.
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Affiliation(s)
- Christopher J. Potter
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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35
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Zhao Z, Tian D, McBride CS. Development of a pan-neuronal genetic driver in Aedes aegypti mosquitoes. CELL REPORTS METHODS 2021; 1:100042. [PMID: 34590074 PMCID: PMC8478256 DOI: 10.1016/j.crmeth.2021.100042] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 05/10/2021] [Accepted: 06/07/2021] [Indexed: 01/19/2023]
Abstract
The recent development of neurogenetic tools in Aedes aegypti mosquitoes is beginning to shed light on the neural basis of behaviors that make this species a major vector of human disease. However, we still lack a pan-neuronal expression driver-a key tool that provides genetic access to all neurons. Here, we describe our efforts to fill this gap via CRISPR/Cas9-mediated knock-in of reporters to broadly expressed neural genes and report on the generation of two strains, a Syt1:GCaMP6s strain that expresses synaptically localized GCaMP and a brp-T2A-QF2w driver strain that can be used to drive and amplify expression of any effector via the Q binary system. Both manipulations broadly and uniformly label the nervous system with only modest effects on behavior. We expect these strains to facilitate neurobiological research in Ae. aegypti mosquitoes and document both successful and failed manipulations as a roadmap for similar tool development in other non-model species.
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Affiliation(s)
- Zhilei Zhao
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - David Tian
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Carolyn S. McBride
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
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36
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Tissue-specific dynamic codon redefinition in Drosophila. Proc Natl Acad Sci U S A 2021; 118:2012793118. [PMID: 33500350 DOI: 10.1073/pnas.2012793118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Translational stop codon readthrough occurs in organisms ranging from viruses to mammals and is especially prevalent in decoding Drosophila and viral mRNAs. Recoding of UGA, UAG, or UAA to specify an amino acid allows a proportion of the protein encoded by a single gene to be C-terminally extended. The extended product from Drosophila kelch mRNA is 160 kDa, whereas unextended Kelch protein, a subunit of a Cullin3-RING ubiquitin ligase, is 76 kDa. Previously we reported tissue-specific regulation of readthrough of the first kelch stop codon. Here, we characterize major efficiency differences in a variety of cell types. Immunoblotting revealed low levels of readthrough in malpighian tubules, ovary, and testis but abundant readthrough product in lysates of larval and adult central nervous system (CNS) tissue. Reporters of readthrough demonstrated greater than 30% readthrough in adult brains, and imaging in larval and adult brains showed that readthrough occurred in neurons but not glia. The extent of readthrough stimulatory sequences flanking the readthrough stop codon was assessed in transgenic Drosophila and in human tissue culture cells where inefficient readthrough occurs. A 99-nucleotide sequence with potential to form an mRNA stem-loop 3' of the readthrough stop codon stimulated readthrough efficiency. However, even with just six nucleotides of kelch mRNA sequence 3' of the stop codon, readthrough efficiency only dropped to 6% in adult neurons. Finally, we show that high-efficiency readthrough in the Drosophila CNS is common; for many neuronal proteins, C-terminal extended forms of individual proteins are likely relatively abundant.
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Yamagata N, Ezaki T, Takahashi T, Wu H, Tanimoto H. Presynaptic inhibition of dopamine neurons controls optimistic bias. eLife 2021; 10:64907. [PMID: 34061730 PMCID: PMC8169112 DOI: 10.7554/elife.64907] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 05/16/2021] [Indexed: 01/04/2023] Open
Abstract
Regulation of reward signaling in the brain is critical for appropriate judgement of the environment and self. In Drosophila, the protocerebral anterior medial (PAM) cluster dopamine neurons mediate reward signals. Here, we show that localized inhibitory input to the presynaptic terminals of the PAM neurons titrates olfactory reward memory and controls memory specificity. The inhibitory regulation was mediated by metabotropic gamma-aminobutyric acid (GABA) receptors clustered in presynaptic microdomain of the PAM boutons. Cell type-specific silencing the GABA receptors enhanced memory by augmenting internal reward signals. Strikingly, the disruption of GABA signaling reduced memory specificity to the rewarded odor by changing local odor representations in the presynaptic terminals of the PAM neurons. The inhibitory microcircuit of the dopamine neurons is thus crucial for both reward values and memory specificity. Maladaptive presynaptic regulation causes optimistic cognitive bias.
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Affiliation(s)
| | - Takahiro Ezaki
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | | | - Hongyang Wu
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Hiromu Tanimoto
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
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A selectable, plasmid-based system to generate CRISPR/Cas9 gene edited and knock-in mosquito cell lines. Sci Rep 2021; 11:736. [PMID: 33436886 PMCID: PMC7804293 DOI: 10.1038/s41598-020-80436-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/20/2020] [Indexed: 12/15/2022] Open
Abstract
Aedes (Ae.) aegypti and Ae. albopictus mosquitoes transmit arthropod-borne diseases around the globe, causing ~ 700,000 deaths each year. Genetic mutants are valuable tools to interrogate both fundamental vector biology and mosquito host factors important for viral infection. However, very few genetic mutants have been described in mosquitoes in comparison to model organisms. The relative ease of applying CRISPR/Cas9-based gene editing has transformed genome engineering and has rapidly increased the number of available gene mutants in mosquitoes. Yet, in vivo studies may not be practical for screening large sets of mutants or possible for laboratories that lack insectaries. Thus, it would be useful to adapt CRISPR/Cas9 systems to common mosquito cell lines. In this study, we generated and characterized a mosquito optimized, plasmid-based CRISPR/Cas9 system for use in U4.4 (Ae. albopictus) and Aag2 (Ae. aegypti) cell lines. We demonstrated highly efficient editing of the AGO1 locus and isolated U4.4 and Aag2 cell lines with reduced AGO1 expression. Further, we used homology-directed repair to establish knock-in Aag2 cell lines with a 3xFLAG-tag at the N-terminus of endogenous AGO1. These experimentally verified plasmids are versatile, cost-effective, and efficiently edit immune competent mosquito cell lines that are widely used in arbovirus studies.
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Luan H, Diao F, Scott RL, White BH. The Drosophila Split Gal4 System for Neural Circuit Mapping. Front Neural Circuits 2020; 14:603397. [PMID: 33240047 PMCID: PMC7680822 DOI: 10.3389/fncir.2020.603397] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 10/06/2020] [Indexed: 12/22/2022] Open
Abstract
The diversity and dense interconnectivity of cells in the nervous system present a huge challenge to understanding how brains work. Recent progress toward such understanding, however, has been fuelled by the development of techniques for selectively monitoring and manipulating the function of distinct cell types-and even individual neurons-in the brains of living animals. These sophisticated techniques are fundamentally genetic and have found their greatest application in genetic model organisms, such as the fruit fly Drosophila melanogaster. Drosophila combines genetic tractability with a compact, but cell-type rich, nervous system and has been the incubator for a variety of methods of neuronal targeting. One such method, called Split Gal4, is playing an increasingly important role in mapping neural circuits in the fly. In conjunction with functional perturbations and behavioral screens, Split Gal4 has been used to characterize circuits governing such activities as grooming, aggression, and mating. It has also been leveraged to comprehensively map and functionally characterize cells composing important brain regions, such as the central complex, lateral horn, and the mushroom body-the latter being the insect seat of learning and memory. With connectomics data emerging for both the larval and adult brains of Drosophila, Split Gal4 is also poised to play an important role in characterizing neurons of interest based on their connectivity. We summarize the history and current state of the Split Gal4 method and indicate promising areas for further development or future application.
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Affiliation(s)
| | | | | | - Benjamin H. White
- Laboratory of Molecular Biology, National Institute of Mental Health, NIH, Bethesda, MD, United States
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40
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Cofactor-enabled functional expression of fruit fly, honeybee, and bumblebee nicotinic receptors reveals picomolar neonicotinoid actions. Proc Natl Acad Sci U S A 2020; 117:16283-16291. [PMID: 32611810 PMCID: PMC7368294 DOI: 10.1073/pnas.2003667117] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neonicotinoids acting on insect nicotinic acetylcholine receptors (nAChRs) are deployed for crop protection, but growing evidence for adverse effects on insect pollinators has led to restricted use of some neonicotinoids in the EU. It is therefore vital to understand the target site actions of neonicotinoids in pollinators, but to date the difficulties of heterologous expression of insect nAChRs have hampered progress. We have found that a thioredoxin (TMX3) enables robust functional expression of honeybee, bumblebee, and fruit fly nAChRs in Xenopus laevis oocytes. With this advance, we show that expressed bee nAChRs are more neonicotinoid-sensitive than those of fruit fly, and clothianidin can modulate both honeybee and bumblebee nAChRs at a concentration below that commonly observed in agricultural fields. The difficulty of achieving robust functional expression of insect nicotinic acetylcholine receptors (nAChRs) has hampered our understanding of these important molecular targets of globally deployed neonicotinoid insecticides at a time when concerns have grown regarding the toxicity of this chemotype to insect pollinators. We show that thioredoxin-related transmembrane protein 3 (TMX3) is essential to enable robust expression in Xenopus laevis oocytes of honeybee (Apis mellifera) and bumblebee (Bombus terrestris) as well as fruit fly (Drosophila melanogaster) nAChR heteromers targeted by neonicotinoids and not hitherto robustly expressed. This has enabled the characterization of picomolar target site actions of neonicotinoids, findings important in understanding their toxicity.
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41
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Xie J, Sang M, Song X, Zhang S, Kim D, Veenstra JA, Park Y, Li B. A new neuropeptide insect parathyroid hormone iPTH in the red flour beetle Tribolium castaneum. PLoS Genet 2020; 16:e1008772. [PMID: 32365064 PMCID: PMC7224569 DOI: 10.1371/journal.pgen.1008772] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 05/14/2020] [Accepted: 04/09/2020] [Indexed: 12/15/2022] Open
Abstract
In the postgenomics era, comparative genomics have advanced the understanding of evolutionary processes of neuropeptidergic signaling systems. The evolutionary origin of many neuropeptidergic signaling systems can be traced date back to early metazoan evolution based on the conserved sequences. Insect parathyroid hormone receptor (iPTHR) was previously described as an ortholog of vertebrate PTHR that has a well-known function in controlling bone remodeling. However, there was no sequence homologous to PTH sequence in insect genomes, leaving the iPTHR as an orphan receptor. Here, we identified the authentic ligand insect PTH (iPTH) for the iPTHR. The taxonomic distribution of iPTHR, which is lacking in Diptera and Lepidoptera, provided a lead for identifying the authentic ligand. We found that a previously described orphan ligand known as PXXXamide (where X is any amino acid) described in the cuttlefish Sepia officinalis has a similar taxonomic distribution pattern as iPTHR. Tests of this peptide, iPTH, in functional reporter assays confirmed the interaction of the ligand-receptor pair. Study of a model beetle, Tribolium castaneum, was used to investigate the function of the iPTH signaling system by RNA interference followed by RNA sequencing and phenotyping. The results suggested that the iPTH system is likely involved in the regulation of cuticle formation that culminates with a phenotype of defects in wing exoskeleton maturation at the time of adult eclosion. Moreover, RNAi of iPTHRs also led to significant reductions in egg numbers and hatching rates after parental RNAi. Vertebrate parathyroid hormone (PTH) and its receptors have been extensively studied with respect to their function in bone remodeling and calcium metabolism. Insect parathyroid hormone receptors (iPTHRs) have been previously described as counterparts of vertebrate PTHRs, however, they are still orphan receptors for which the authentic ligands and biological functions remain unknown. We describe an insect form of parathyroid hormone (iPTH) by analyzing its interactions with iPTHRs. Identification of this new insect peptidergic system proved that the PTH system is an ancestral signaling system dating back to the evolutionary time before the divergence of protostomes and deuterostomes. We also investigated the functions of the iPTH system in a model beetle Tribolium castaneum by using RNA interference. RNA interference of iPTHR resulted in defects in wing exoskeleton maturation and fecundity. Based on the differential gene expression patterns and the phenotype induced by RNAi, we propose that the iPTH system is likely involved in the regulation of exoskeletal cuticle formation and fecundity in insects.
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Affiliation(s)
- Jia Xie
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
- Department of Entomology, Kansas State University, Manhattan, KS, United States of America
| | - Ming Sang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Xiaowen Song
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Sisi Zhang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Donghun Kim
- Department of Entomology, Kansas State University, Manhattan, KS, United States of America
- Department of Applied Biology, Kyungpook National University, Sangju, Korea
| | - Jan A. Veenstra
- INCIA UMR 5287 CNRS, University of Bordeaux, Pessac, France
- * E-mail: (JAV); (YP); (BL)
| | - Yoonseong Park
- Department of Entomology, Kansas State University, Manhattan, KS, United States of America
- * E-mail: (JAV); (YP); (BL)
| | - Bin Li
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
- * E-mail: (JAV); (YP); (BL)
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42
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Luan H, Kuzin A, Odenwald WF, White BH. Cre-assisted fine-mapping of neural circuits using orthogonal split inteins. eLife 2020; 9:e53041. [PMID: 32286225 PMCID: PMC7217698 DOI: 10.7554/elife.53041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 04/11/2020] [Indexed: 01/18/2023] Open
Abstract
Existing genetic methods of neuronal targeting do not routinely achieve the resolution required for mapping brain circuits. New approaches are thus necessary. Here, we introduce a method for refined neuronal targeting that can be applied iteratively. Restriction achieved at the first step can be further refined in a second step, if necessary. The method relies on first isolating neurons within a targeted group (i.e. Gal4 pattern) according to their developmental lineages, and then intersectionally limiting the number of lineages by selecting only those in which two distinct neuroblast enhancers are active. The neuroblast enhancers drive expression of split Cre recombinase fragments. These are fused to non-interacting pairs of split inteins, which ensure reconstitution of active Cre when all fragments are expressed in the same neuroblast. Active Cre renders all neuroblast-derived cells in a lineage permissive for Gal4 activity. We demonstrate how this system can facilitate neural circuit-mapping in Drosophila.
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Affiliation(s)
- Haojiang Luan
- Laboratory of Molecular Biology, National Institute of Mental Health, NIHBethesdaUnited States
| | - Alexander Kuzin
- Neural Cell-Fate Determinants Section, National Institute of Neurological Disorders and Stroke, NIHBethesdaUnited States
| | - Ward F Odenwald
- Neural Cell-Fate Determinants Section, National Institute of Neurological Disorders and Stroke, NIHBethesdaUnited States
| | - Benjamin H White
- Laboratory of Molecular Biology, National Institute of Mental Health, NIHBethesdaUnited States
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43
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Flaven-Pouchon J, Alvarez JV, Rojas C, Ewer J. The tanning hormone, bursicon, does not act directly on the epidermis to tan the Drosophila exoskeleton. BMC Biol 2020; 18:17. [PMID: 32075655 PMCID: PMC7029472 DOI: 10.1186/s12915-020-0742-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/24/2020] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND In insects, continuous growth requires the periodic replacement of the exoskeleton. Once the remains of the exoskeleton from the previous stage have been shed during ecdysis, the new one is rapidly sclerotized (hardened) and melanized (pigmented), a process collectively known as tanning. The rapid tanning that occurs after ecdysis is critical for insect survival, as it reduces desiccation, and gives the exoskeleton the rigidity needed to support the internal organs and to provide a solid anchor for the muscles. This rapid postecdysial tanning is triggered by the "tanning hormone", bursicon. Since bursicon is released into the hemolymph, it has naturally been assumed that it would act on the epidermal cells to cause the tanning of the overlying exoskeleton. RESULTS Here we investigated the site of bursicon action in Drosophila by examining the consequences on tanning of disabling the bursicon receptor (encoded by the rickets gene) in different tissues. To our surprise, we found that rapid tanning does not require rickets function in the epidermis but requires it instead in peptidergic neurons of the ventral nervous system (VNS). Although we were unable to identify the signal that is transmitted from the VNS to the epidermis, we show that neurons that express the Drosophila insulin-like peptide ILP7, but not the ILP7 peptide itself, are involved. In addition, we found that some of the bursicon targets involved in melanization are different from those that cause sclerotization. CONCLUSIONS Our findings show that bursicon does not act directly on the epidermis to cause the tanning of the overlying exoskeleton but instead requires an intermediary messenger produced by peptidergic neurons within the central nervous system. Thus, this work has uncovered an unexpected layer of control in a process that is critical for insect survival, which will significantly alter the direction of future research aimed at understanding how rapid postecdysial tanning occurs.
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Affiliation(s)
| | - Javier V Alvarez
- Instituto de Neurociencia, Universidad de Valparaíso, Valparaiso, Chile
| | - Candy Rojas
- Instituto de Neurociencia, Universidad de Valparaíso, Valparaiso, Chile
| | - John Ewer
- Instituto de Neurociencia, Universidad de Valparaíso, Valparaiso, Chile.
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44
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Bosch JA, Colbeth R, Zirin J, Perrimon N. Gene Knock-Ins in Drosophila Using Homology-Independent Insertion of Universal Donor Plasmids. Genetics 2020; 214:75-89. [PMID: 31685521 PMCID: PMC6944404 DOI: 10.1534/genetics.119.302819] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 10/25/2019] [Indexed: 11/18/2022] Open
Abstract
Targeted genomic knock-ins are a valuable tool to probe gene function. However, knock-in methods involving homology-directed repair (HDR) can be laborious. Here, we adapt the mammalian CRISPaint [clustered regularly interspaced short palindromic repeat (CRISPR)-assisted insertion tagging] homology-independent knock-in method for Drosophila melanogaster, which uses CRISPR/Cas9 and nonhomologous end joining to insert "universal" donor plasmids into the genome. Using this method in cultured S2R+ cells, we efficiently tagged four endogenous proteins with the bright fluorescent protein mNeonGreen, thereby demonstrating that an existing collection of CRISPaint universal donor plasmids is compatible with insect cells. In addition, we inserted the transgenesis marker 3xP3-red fluorescent protein into seven genes in the fly germ line, producing heritable loss-of-function alleles that were isolated by simple fluorescence screening. Unlike in cultured cells, insertions/deletions always occurred at the genomic insertion site, which prevents predictably matching the insert coding frame to the target gene. Despite this effect, we were able to isolate T2A-Gal4 insertions in four genes that serve as in vivo expression reporters. Therefore, homology-independent insertion in Drosophila is a fast and simple alternative to HDR that will enable researchers to dissect gene function.
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Affiliation(s)
- Justin A Bosch
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115
| | - Ryan Colbeth
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115
| | - Jonathan Zirin
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115
- Howard Hughes Medical Institute, Boston, Massachusetts 02115
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45
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Neurochemical Organization of the Drosophila Brain Visualized by Endogenously Tagged Neurotransmitter Receptors. Cell Rep 2020; 30:284-297.e5. [DOI: 10.1016/j.celrep.2019.12.018] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 10/19/2019] [Accepted: 12/06/2019] [Indexed: 02/08/2023] Open
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46
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Wang J, Rousseau J, Kim E, Ehresmann S, Cheng YT, Duraine L, Zuo Z, Park YJ, Li-Kroeger D, Bi W, Wong LJ, Rosenfeld J, Gleeson J, Faqeih E, Alkuraya FS, Wierenga KJ, Chen J, Afenjar A, Nava C, Doummar D, Keren B, Juusola J, Grompe M, Bellen HJ, Campeau PM. Loss of Oxidation Resistance 1, OXR1, Is Associated with an Autosomal-Recessive Neurological Disease with Cerebellar Atrophy and Lysosomal Dysfunction. Am J Hum Genet 2019; 105:1237-1253. [PMID: 31785787 PMCID: PMC6904826 DOI: 10.1016/j.ajhg.2019.11.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Accepted: 11/01/2019] [Indexed: 12/28/2022] Open
Abstract
We report an early-onset autosomal-recessive neurological disease with cerebellar atrophy and lysosomal dysfunction. We identified bi-allelic loss-of-function (LoF) variants in Oxidative Resistance 1 (OXR1) in five individuals from three families; these individuals presented with a history of severe global developmental delay, current intellectual disability, language delay, cerebellar atrophy, and seizures. While OXR1 is known to play a role in oxidative stress resistance, its molecular functions are not well established. OXR1 contains three conserved domains: LysM, GRAM, and TLDc. The gene encodes at least six transcripts, including some that only consist of the C-terminal TLDc domain. We utilized Drosophila to assess the phenotypes associated with loss of mustard (mtd), the fly homolog of OXR1. Strong LoF mutants exhibit late pupal lethality or pupal eclosion defects. Interestingly, although mtd encodes 26 transcripts, severe LoF and null mutations can be rescued by a single short human OXR1 cDNA that only contains the TLDc domain. Similar rescue is observed with the TLDc domain of NCOA7, another human homolog of mtd. Loss of mtd in neurons leads to massive cell loss, early death, and an accumulation of aberrant lysosomal structures, similar to what we observe in fibroblasts of affected individuals. Our data indicate that mtd and OXR1 are required for proper lysosomal function; this is consistent with observations that NCOA7 is required for lysosomal acidification.
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Affiliation(s)
- Julia Wang
- Program in Developmental Biology, Medical Scientist Training Program, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Justine Rousseau
- Centre Hospitalier Universitaire Saint-Justine Research Center, CHU Sainte-Justine, Montreal, QC H3T 1J4, Canada
| | - Emily Kim
- Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA
| | - Sophie Ehresmann
- Centre Hospitalier Universitaire Saint-Justine Research Center, CHU Sainte-Justine, Montreal, QC H3T 1J4, Canada
| | - Yi-Ting Cheng
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lita Duraine
- Jan and Dan Duncan Neurological Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zhongyuan Zuo
- Jan and Dan Duncan Neurological Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ye-Jin Park
- Jan and Dan Duncan Neurological Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - David Li-Kroeger
- Jan and Dan Duncan Neurological Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Weimin Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lee-Jun Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jill Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Joseph Gleeson
- Rady Institute of Genomic Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Eissa Faqeih
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, 11525, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, 11525, Saudi Arabia
| | - Klaas J Wierenga
- Department of Pediatrics, Oklahoma University Health Sciences Center (OUHSC), Oklahoma City, OK 26901, USA; Department of Clinical Genomics, Mayo Clinic Florida, Jacksonville, FL 32224, USA
| | - Jiani Chen
- Department of Pediatrics, Oklahoma University Health Sciences Center (OUHSC), Oklahoma City, OK 26901, USA; Division of Genomic Diagnostics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Alexandra Afenjar
- Assistance Publique des Hôpitaux de Paris, Unité de Génétique Clinique, Hôpital Armand Trousseau, Groupe Hospitalier Universitaire Paris, 75012, France; Département de Génétique et Embryologie Médicale, CRMR des Malformations et Maladies Congénitales du Cervelet, GRC ConCer-LD, Sorbonne Universités, Hôpital Trousseau, Paris, 75012 France
| | - Caroline Nava
- Assistance Publique des Hôpitaux de Paris, Unité de Génétique Clinique, Hôpital Armand Trousseau, Groupe Hospitalier Universitaire Paris, 75012, France
| | - Diane Doummar
- Assistance Publique des Hôpitaux de Paris, Service de Neuropédiatrie, Hôpital Armand Trousseau, Groupe Hospitalier Universitaire Paris, 75012 France
| | - Boris Keren
- Assistance Publique des Hôpitaux de Paris, Unité de Génétique Clinique, Hôpital Armand Trousseau, Groupe Hospitalier Universitaire Paris, 75012, France
| | | | - Markus Grompe
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon 97201, USA; Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon 97201, USA
| | - Hugo J Bellen
- Jan and Dan Duncan Neurological Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Howard Hughes Medical Institute and Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Philippe M Campeau
- Centre Hospitalier Universitaire Saint-Justine Research Center, CHU Sainte-Justine, Montreal, QC H3T 1J4, Canada.
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Bellen HJ, Wangler MF, Yamamoto S. The fruit fly at the interface of diagnosis and pathogenic mechanisms of rare and common human diseases. Hum Mol Genet 2019; 28:R207-R214. [PMID: 31227826 PMCID: PMC6872428 DOI: 10.1093/hmg/ddz135] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 05/31/2019] [Accepted: 06/07/2019] [Indexed: 12/12/2022] Open
Abstract
Drosophila melanogaster is a unique, powerful genetic model organism for studying a broad range of biological questions. Human studies that probe the genetic causes of rare and undiagnosed diseases using massive-parallel sequencing often require complementary gene function studies to determine if and how rare variants affect gene function. These studies also provide inroads to disease mechanisms and therapeutic targets. In this review we discuss strategies for functional studies of rare human variants in Drosophila. We focus on our experience in establishing a Drosophila core of the Model Organisms Screening Center for the Undiagnosed Diseases Network (UDN) and concurrent fly studies with other large genomic rare disease research efforts such as the Centers for Mendelian Genomics. We outline four major strategies that use the latest technology in fly genetics to understand the impact of human variants on gene function. We also mention general concepts in probing disease mechanisms, therapeutics and using rare disease to understand common diseases. Drosophila is and will continue to be a fundamental genetic model to identify new disease-causing variants, pathogenic mechanisms and drugs that will impact medicine.
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Affiliation(s)
- Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine (BCM), Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX , USA
- Howard Hughes Medical Institute, Houston, TX, USA
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX , USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine (BCM), Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX , USA
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Gu P, Gong J, Shang Y, Wang F, Ruppell KT, Ma Z, Sheehan AE, Freeman MR, Xiang Y. Polymodal Nociception in Drosophila Requires Alternative Splicing of TrpA1. Curr Biol 2019; 29:3961-3973.e6. [PMID: 31735672 DOI: 10.1016/j.cub.2019.09.070] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 09/25/2019] [Accepted: 09/27/2019] [Indexed: 12/29/2022]
Abstract
Transcripts of noxious stimulus-detecting TrpA1 channels are alternatively spliced. Despite the importance of nociception for survival, the in vivo significance of expressing different TrpA1 isoforms is largely unknown. Here, we develop a novel genetic approach to generate Drosophila knockin strains expressing single TrpA1 isoforms. Drosophila TrpA1 mediates heat and UVC-triggered nociception. We show that TrpA1-C and TrpA1-D, two alternative isoforms, are co-expressed in nociceptors. When examined in heterologous cells, both TrpA1-C and TrpA1-D are activated by heat and UVC. By contrast, analysis of knockin flies reveals the striking functional specificity; TrpA1-C mediates UVC-nociception, whereas TrpA1-D mediates heat-nociception. Therefore, in vivo functions of TrpA1-C and TrpA1-D are different from each other and are different from their in vitro properties. Our results indicate that a given sensory stimulus preferentially activates a single TrpA1 isoform in vivo and that polymodal nociception requires co-expression of TrpA1 isoforms, providing novel insights of how alternative splicing regulates nociception.
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Affiliation(s)
- Pengyu Gu
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jiaxin Gong
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ye Shang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Fei Wang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Kendra T Ruppell
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Zhiguo Ma
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Amy E Sheehan
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Marc R Freeman
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Yang Xiang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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Wu L, Jia Q, Zhang X, Zhang X, Liu S, Park Y, Feyereisen R, Zhu KY, Ma E, Zhang J, Li S. CYP303A1 has a conserved function in adult eclosion in Locusta migratoria and Drosophila melanogaster. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 113:103210. [PMID: 31422152 DOI: 10.1016/j.ibmb.2019.103210] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/15/2019] [Accepted: 07/15/2019] [Indexed: 06/10/2023]
Abstract
Insect cytochrome P450 monooxygenases (CYPs) play essential roles in both xenobiotic metabolism and developmental processes. However, the exact physiological function of many CYP genes remains largely unknown. Screening the expression of the CYP genes from the CYP2 and mitochondrial CYP clans of Drosophila melanogaster revealed that Cyp303a1 is highly expressed in the pupal stage. Knockdown of CYP303A1 transcripts by RNAi using the Gal4/UAS system with a ubiquitous driver (tubulin-Gal4) in Drosophila or by dsRNA injection in the last nymph stage of Locusta migratoria resulted in severe defects in eclosion and lethality during and after adult emergence. In Drosophila, tissue-specific RNAi of Cyp303a1 with a wing-specific driver (MS1096-Gal4) revealed that Cyp303a1 was essential for wing extension. Stage-specific RNAi of Cyp303a1 using Gal80ts for thermal-dependent-suppression found that the expression of Cyp303a1 at the middle pupal stage was absolutely required. Meanwhile, Cyp303a1 mutants exhibited more than 80% lethality at the late embryonic development stages. Embryonic lethality of the Cyp303a1 mutants was fully rescued by the ubiquitous overexpression of exogenous Cyp303a1. Taken together, we conclude that Cyp303a1 is indispensable for embryonic development and adult eclosion in D. melanogaster, the latter role being conserved over 400 million years of insect evolution.
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Affiliation(s)
- Lixian Wu
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China; College of Life Science, Shanxi University, Taiyuan, Shanxi 030006, China; Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Qiangqiang Jia
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Xubo Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Xueyao Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Suning Liu
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Yoonseong Park
- Department of Entomology, Kansas State University, Manhattan, KS 66506, USA
| | - René Feyereisen
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen 1017, Denmark; Department of Plant and Crops, Ghent University, B-9000 Ghent, Belgium
| | - Kun Yan Zhu
- Department of Entomology, Kansas State University, Manhattan, KS 66506, USA
| | - Enbo Ma
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Jianzhen Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China.
| | - Sheng Li
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China.
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50
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Harnish JM, Deal SL, Chao HT, Wangler MF, Yamamoto S. In Vivo Functional Study of Disease-associated Rare Human Variants Using Drosophila. J Vis Exp 2019:10.3791/59658. [PMID: 31498321 PMCID: PMC7418855 DOI: 10.3791/59658] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Advances in sequencing technology have made whole-genome and whole-exome datasets more accessible for both clinical diagnosis and cutting-edge human genetics research. Although a number of in silico algorithms have been developed to predict the pathogenicity of variants identified in these datasets, functional studies are critical to determining how specific genomic variants affect protein function, especially for missense variants. In the Undiagnosed Diseases Network (UDN) and other rare disease research consortia, model organisms (MO) including Drosophila, C. elegans, zebrafish, and mice are actively used to assess the function of putative human disease-causing variants. This protocol describes a method for the functional assessment of rare human variants used in the Model Organisms Screening Center Drosophila Core of the UDN. The workflow begins with gathering human and MO information from multiple public databases, using the MARRVEL web resource to assess whether the variant is likely to contribute to a patient's condition as well as design effective experiments based on available knowledge and resources. Next, genetic tools (e.g., T2A-GAL4 and UAS-human cDNA lines) are generated to assess the functions of variants of interest in Drosophila. Upon development of these reagents, two-pronged functional assays based on rescue and overexpression experiments can be performed to assess variant function. In the rescue branch, the endogenous fly genes are "humanized" by replacing the orthologous Drosophila gene with reference or variant human transgenes. In the overexpression branch, the reference and variant human proteins are exogenously driven in a variety of tissues. In both cases, any scorable phenotype (e.g., lethality, eye morphology, electrophysiology) can be used as a read-out, irrespective of the disease of interest. Differences observed between reference and variant alleles suggest a variant-specific effect, and thus likely pathogenicity. This protocol allows rapid, in vivo assessments of putative human disease-causing variants of genes with known and unknown functions.
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Affiliation(s)
- J Michael Harnish
- Department of Molecular and Human Genetics, Baylor College of Medicine
| | - Samantha L Deal
- Program in Developmental Biology, Baylor College of Medicine
| | - Hsiao-Tuan Chao
- Department of Molecular and Human Genetics, Baylor College of Medicine; Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital; Department of Neuroscience, Baylor College of Medicine
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine; Program in Developmental Biology, Baylor College of Medicine; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine; Program in Developmental Biology, Baylor College of Medicine; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital; Department of Neuroscience, Baylor College of Medicine;
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