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Malin J, Rosa-Birriel C, Hatini V. Pten, PI3K, and PtdIns(3,4,5)P 3 dynamics control pulsatile actin branching in Drosophila retina morphogenesis. Dev Cell 2024; 59:1593-1608.e6. [PMID: 38640926 DOI: 10.1016/j.devcel.2024.03.035] [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] [Received: 04/12/2023] [Revised: 11/28/2023] [Accepted: 03/25/2024] [Indexed: 04/21/2024]
Abstract
Epithelial remodeling of the Drosophila retina depends on the pulsatile contraction and expansion of apical contacts between the cells that form its hexagonal lattice. Phosphoinositide PI(3,4,5)P3 (PIP3) accumulates around tricellular adherens junctions (tAJs) during contact expansion and dissipates during contraction, but with unknown function. Here, we found that manipulations of Pten or PI3-kinase (PI3K) that either decreased or increased PIP3 resulted in shortened contacts and a disordered lattice, indicating a requirement for PIP3 dynamics and turnover. These phenotypes are caused by a loss of branched actin, resulting from impaired activity of the Rac1 Rho GTPase and the WAVE regulatory complex (WRC). We additionally found that during contact expansion, PI3K moves into tAJs to promote the cyclical increase of PIP3 in a spatially and temporally precise manner. Thus, dynamic control of PIP3 by Pten and PI3K governs the protrusive phase of junctional remodeling, which is essential for planar epithelial morphogenesis.
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Affiliation(s)
- Jacob Malin
- Tufts University School of Medicine, Department of Developmental, Molecular & Chemical Biology, Program in Genetics, Molecular and Cellular Biology, and Program in Pharmacology and Experimental Therapeutics, 150 Harrison Avenue, Boston, MA 02111, USA
| | - Christian Rosa-Birriel
- Tufts University School of Medicine, Department of Developmental, Molecular & Chemical Biology, Program in Genetics, Molecular and Cellular Biology, and Program in Pharmacology and Experimental Therapeutics, 150 Harrison Avenue, Boston, MA 02111, USA
| | - Victor Hatini
- Tufts University School of Medicine, Department of Developmental, Molecular & Chemical Biology, Program in Genetics, Molecular and Cellular Biology, and Program in Pharmacology and Experimental Therapeutics, 150 Harrison Avenue, Boston, MA 02111, USA.
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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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Rodante DE, Papávero EB, Ingratta AV, Gorrini A, Ralli E, Rodante ED, Arismendi M, Lowry N, Ryan P, Jian-Ping H, Bridge JA, Horowitz L, Daray FM. Validation of the Spanish ASQ translation: Screening pediatric patients for suicide-risk in Argentina. Gen Hosp Psychiatry 2023; 85:191-198. [PMID: 37952326 DOI: 10.1016/j.genhosppsych.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 11/14/2023]
Abstract
BACKGROUND The high frequency of suicide risk in adolescents necessitates the development and validation of specific tools for systematic screening. To date, there are translated, but not validated suicide risk screening tools in Spanish. OBJECTIVE To validate the Spanish version of the Ask Suicide-Screening Questions (ASQ) for suicide risk screening in pediatric patients in Argentina. METHOD Using a cross-sectional multicenter design, a convenience sample of pediatric patients aged 10 to 18 years old were recruited from outpatient/inpatient medical settings and private psychiatric clinics. The Spanish version of the Suicidal Ideation Questionnaire (SIQ) assessment tool was used as a standard criterion to validate the ASQ. RESULTS A total of 301/380 pediatric patients were screened for suicide risk. Twentyeight percent of the entire sample (83/301) of youth screened positive on the ASQ, and 21% (62/301) screened positive on the SIQ/SIQ-JR and were considered "at risk" for suicide. Compared with the SIQ, the Spanish ASQ yielded a sensitivity of 96.8% (95% Confidence Interval [CI]: 88.8-99.6%), specificity of 90.4% (95% CI: 85.9-93.8%), positive predictive value of 72.3% (95 CI: 61.4-81.6%), and negative predictive value of 99.1% (95% CI: 96.7-99.9%). The positive Likelihood Ratio (LR) was 10.1 (95% CI: 6.1-14.0), and the negative LR was 0.03 (95% CI: -0.01-0.09). Kappa was 0.77 (95% CI: 0.69-0.86), and the Area Under the Curve was 0.94 (95% CI: 0.91-0.97). CONCLUSION The Spanish language ASQ demonstrated strong psychometric properties, providing initial evidence that it is a valid tool for identifying Spanish-speaking youth at risk for suicide.
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Affiliation(s)
- Demian Emanuel Rodante
- Universidad de Buenos Aires, Facultad de Medicina, Instituto de Farmacología, Argentina; Hospital Neuropsiquiátrico Braulio A. Moyano, Ciudad de Buenos Aires, Argentina
| | - Eliana Belén Papávero
- Universidad de Buenos Aires, Facultad de Medicina, Instituto de Farmacología, Argentina; Hospital General de Niños Pedro de Elizalde, Ciudad de Buenos Aires, Argentina
| | | | - Antonio Gorrini
- Hospital Federico Falcon, Pilar, Provincia de Buenos Aires, Argentina
| | - Eugenia Ralli
- Clinica Santa Rosa, Ciudad de Buenos Aires, Argentina
| | | | - Mariana Arismendi
- Hospital Federico Falcon, Pilar, Provincia de Buenos Aires, Argentina
| | - Nathan Lowry
- Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Patrick Ryan
- Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - He Jian-Ping
- Genetic Epidemiology Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Jeffrey A Bridge
- Center for Suicide Prevention Research, Nationwide Children's Hospital, Ohio State University, Columbus, OH, USA
| | - Lisa Horowitz
- Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Federico Manuel Daray
- Universidad de Buenos Aires, Facultad de Medicina, Instituto de Farmacología, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
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Doll RM, Boutros M, Port F. A temperature-tolerant CRISPR base editor mediates highly efficient and precise gene editing in Drosophila. SCIENCE ADVANCES 2023; 9:eadj1568. [PMID: 37647411 PMCID: PMC10468138 DOI: 10.1126/sciadv.adj1568] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/28/2023] [Indexed: 09/01/2023]
Abstract
CRISPR nucleases generate a broad spectrum of mutations that includes undesired editing outcomes. Here, we develop optimized C-to-T base editing systems for the generation of precise loss- or gain-of-function alleles in Drosophila and identify temperature as a crucial parameter for efficiency. We find that a variant of the widely used APOBEC1 deaminase has attenuated activity at 18° to 29°C and shows considerable dose-dependent toxicity. In contrast, the temperature-tolerant evoCDA1 domain mediates editing of typically more than 90% of alleles and is substantially better tolerated. Furthermore, formation of undesired mutations is exceptionally rare in Drosophila compared to other species. The predictable editing outcome, high efficiency, and product purity enables near homogeneous induction of STOP codons or alleles encoding protein variants in vivo. Last, we demonstrate how optimized expression enables conditional base editing in marked cell populations. This work substantially facilitates creation of precise alleles in Drosophila and provides key design parameters for developing efficient base editing systems in other ectothermic species.
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Affiliation(s)
- Roman M. Doll
- German Cancer Research Center (DKFZ), Division of Signaling and Functional Genomics and BioQuant & Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
- Molecular Biosciences/Cancer Biology Program, Heidelberg University and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Boutros
- German Cancer Research Center (DKFZ), Division of Signaling and Functional Genomics and BioQuant & Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Fillip Port
- German Cancer Research Center (DKFZ), Division of Signaling and Functional Genomics and BioQuant & Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
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Malin J, Rosa Birriel C, Hatini V. Pten, Pi3K and PtdIns(3,4,5)P 3 dynamics modulate pulsatile actin branching in Drosophila retina morphogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.533017. [PMID: 36993510 PMCID: PMC10055149 DOI: 10.1101/2023.03.17.533017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Epithelial remodeling of the Drosophila retina depends on the pulsatile contraction and expansion of apical contacts between the cells that form its hexagonal lattice. Phosphoinositide PI(3,4,5)P 3 (PIP 3 ) accumulates around tricellular adherens junctions (tAJs) during contact expansion and dissipates during contraction, but with unknown function. Here we found that manipulations of Pten or Pi3K that either decreased or increased PIP 3 resulted in shortened contacts and a disordered lattice, indicating a requirement for PIP 3 dynamics and turnover. These phenotypes are caused by a loss of protrusive branched actin, resulting from impaired activity of the Rac1 Rho GTPase and the WAVE regulatory complex (WRC). We additionally found that during contact expansion, Pi3K moves into tAJs to promote the cyclical increase of PIP 3 in a spatially and temporally precise manner. Thus, dynamic regulation of PIP 3 by Pten and Pi3K controls the protrusive phase of junctional remodeling, which is essential for planar epithelial morphogenesis.
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6
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Pacheco ID, Walling LL, Atkinson PW. Gene Editing and Genetic Control of Hemipteran Pests: Progress, Challenges and Perspectives. Front Bioeng Biotechnol 2022; 10:900785. [PMID: 35747496 PMCID: PMC9209771 DOI: 10.3389/fbioe.2022.900785] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 05/09/2022] [Indexed: 12/16/2022] Open
Abstract
The origin of the order Hemiptera can be traced to the late Permian Period more than 230 MYA, well before the origin of flowering plants 100 MY later in during the Cretaceous period. Hemipteran species consume their liquid diets using a sucking proboscis; for phytophagous hemipterans their mouthparts (stylets) are elegant structures that enable voracious feeding from plant xylem or phloem. This adaptation has resulted in some hemipteran species becoming globally significant pests of agriculture resulting in significant annual crop losses. Due to the reliance on chemical insecticides for the control of insect pests in agricultural settings, many hemipteran pests have evolved resistance to insecticides resulting in an urgent need to develop new, species-specific and environmentally friendly methods of pest control. The rapid advances in CRISPR/Cas9 technologies in model insects such as Drosophila melanogaster, Tribolium castaneum, Bombyx mori, and Aedes aegypti has spurred a new round of innovative genetic control strategies in the Diptera and Lepidoptera and an increased interest in assessing genetic control technologies for the Hemiptera. Genetic control approaches in the Hemiptera have, to date, been largely overlooked due to the problems of introducing genetic material into the germline of these insects. The high frequency of CRISPR-mediated mutagenesis in model insect species suggest that, if the delivery problem for Hemiptera could be solved, then gene editing in the Hemiptera might be quickly achieved. Significant advances in CRISPR/Cas9 editing have been realized in nine species of Hemiptera over the past 4 years. Here we review progress in the Hemiptera and discuss the challenges and opportunities for extending contemporary genetic control strategies into species in this agriculturally important insect orderr.
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Affiliation(s)
- Inaiara D. Pacheco
- Department of Entomology, University of California, Riverside, Riverside, CA, United States
| | - Linda L. Walling
- Department of Botany & Plant Sciences, University of California, Riverside, Riverside, CA, United States
- Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
| | - Peter W. Atkinson
- Department of Entomology, University of California, Riverside, Riverside, CA, United States
- Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
- *Correspondence: Peter W. Atkinson,
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Lewerentz J, Johansson AM, Larsson J, Stenberg P. Transposon activity, local duplications and propagation of structural variants across haplotypes drive the evolution of the Drosophila S2 cell line. BMC Genomics 2022; 23:276. [PMID: 35392795 PMCID: PMC8991648 DOI: 10.1186/s12864-022-08472-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 03/15/2022] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Immortalized cell lines are widely used model systems whose genomes are often highly rearranged and polyploid. However, their genome structure is seldom deciphered and is thus not accounted for during analyses. We therefore used linked short- and long-read sequencing to perform haplotype-level reconstruction of the genome of a Drosophila melanogaster cell line (S2-DRSC) with a complex genome structure. RESULTS Using a custom implementation (that is designed to use ultra-long reads in complex genomes with nested rearrangements) to call structural variants (SVs), we found that the most common SV was repetitive sequence insertion or deletion (> 80% of SVs), with Gypsy retrotransposon insertions dominating. The second most common SV was local sequence duplication. SNPs and other SVs were rarer, but several large chromosomal translocations and mitochondrial genome insertions were observed. Haplotypes were highly similar at the nucleotide level but structurally very different. Insertion SVs existed at various haplotype frequencies and were unlinked on chromosomes, demonstrating that haplotypes have different structures and suggesting the existence of a mechanism that allows SVs to propagate across haplotypes. Finally, using public short-read data, we found that transposable element insertions and local duplications are common in other D. melanogaster cell lines. CONCLUSIONS The S2-DRSC cell line evolved through retrotransposon activity and vast local sequence duplications, that we hypothesize were the products of DNA re-replication events. Additionally, mutations can propagate across haplotypes (possibly explained by mitotic recombination), which enables fine-tuning of mutational impact and prevents accumulation of deleterious events, an inherent problem of clonal reproduction. We conclude that traditional linear homozygous genome representation conceals the complexity when dealing with rearranged and heterozygous clonal cells.
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Affiliation(s)
- Jacob Lewerentz
- Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Västerbotten, Sweden.
| | - Anna-Mia Johansson
- Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Västerbotten, Sweden
| | - Jan Larsson
- Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Västerbotten, Sweden.
| | - Per Stenberg
- Department of Ecology and Environmental Sciences, Umeå University, SE-901 87, Umeå, Västerbotten, Sweden.
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8
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Port F, Boutros M. Tissue-Specific CRISPR-Cas9 Screening in Drosophila. Methods Mol Biol 2022; 2540:157-176. [PMID: 35980577 DOI: 10.1007/978-1-0716-2541-5_7] [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: 06/15/2023]
Abstract
Over the last century research in Drosophila has resulted in many fundamental contributions to our understanding of the biology of multicellular organisms. Many of these breakthroughs have been based on the identification of novel gene functions in large-scale genetic screens. However, conventional forward-genetic screens have been limited by the random nature of mutagenesis and difficulties in mapping causal mutations, while reverse-genetic RNAi screens suffer from incomplete knockdown of gene expression. Recently developed large-scale CRISPR-Cas9 libraries promise to address these limitations by allowing the induction of targeted mutations in genes with spatial and temporal control. Here, we provide a guide for tissue-specific CRISPR screening in Drosophila, including the characterization of Gal4 UAS-Cas9 lines, selection of sgRNA libraries, and various quality control measures. We also discuss confounding factors that can give rise to false-positive and false-negative results in such experiments and suggest strategies on how to detect and avoid them. Conditional CRISPR screening represents an exciting new approach for functional genomics in vivo and is set to further expand our knowledge of the molecular underpinning of development, homeostasis, and disease.
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Affiliation(s)
- Fillip Port
- Division Signaling and Functional Genomics, German Cancer Research Center (DKFZ) and Heidelberg University, Heidelberg, Germany
| | - Michael Boutros
- Division Signaling and Functional Genomics, German Cancer Research Center (DKFZ) and Heidelberg University, Heidelberg, Germany.
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9
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Raghu P, Basak B, Krishnan H. Emerging perspectives on multidomain phosphatidylinositol transfer proteins. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158984. [PMID: 34098114 PMCID: PMC7611342 DOI: 10.1016/j.bbalip.2021.158984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 05/23/2021] [Accepted: 05/25/2021] [Indexed: 12/09/2022]
Abstract
The phosphatidylinositol transfer protein domain (PITPd) is an evolutionarily conserved protein that is able to transfer phosphatidylinositol between membranes in vitro and in vivo. However some animal genomes also include genes that encode proteins where the PITPd is found in cis with a number of additional domains and recent large scale genome sequencing efforts indicate that this type of multidomain architecture is widespread in the animal kingdom. In Drosophila photoreceptors, the multidomain phosphatidylinositol transfer protein RDGB is required to regulate phosphoinositide turnover during G-protein activated phospholipase C signalling. Recent studies in flies and mammalian cell culture models have begun to elucidate functions for the non-PITPd of RDGB and its vertebrate orthologs. We review emerging evidence on the genomics, functional and cell biological perspectives of these multi-domain PITPd containing proteins.
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Affiliation(s)
- Padinjat Raghu
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India.
| | - Bishal Basak
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India
| | - Harini Krishnan
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India
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10
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Smylla TK, Wagner K, Huber A. Application of Fluorescent Proteins for Functional Dissection of the Drosophila Visual System. Int J Mol Sci 2021; 22:8930. [PMID: 34445636 PMCID: PMC8396179 DOI: 10.3390/ijms22168930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/13/2021] [Accepted: 08/14/2021] [Indexed: 11/22/2022] Open
Abstract
The Drosophila eye has been used extensively to study numerous aspects of biological systems, for example, spatio-temporal regulation of differentiation, visual signal transduction, protein trafficking and neurodegeneration. Right from the advent of fluorescent proteins (FPs) near the end of the millennium, heterologously expressed fusion proteins comprising FPs have been applied in Drosophila vision research not only for subcellular localization of proteins but also for genetic screens and analysis of photoreceptor function. Here, we summarize applications for FPs used in the Drosophila eye as part of genetic screens, to study rhodopsin expression patterns, subcellular protein localization, membrane protein transport or as genetically encoded biosensors for Ca2+ and phospholipids in vivo. We also discuss recently developed FPs that are suitable for super-resolution or correlative light and electron microscopy (CLEM) approaches. Illustrating the possibilities provided by using FPs in Drosophila photoreceptors may aid research in other sensory or neuronal systems that have not yet been studied as well as the Drosophila eye.
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Affiliation(s)
- Thomas K. Smylla
- Department of Biochemistry, Institute of Biology, University of Hohenheim, 70599 Stuttgart, Germany; (K.W.); (A.H.)
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11
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Trivedi D. Using CRISPR-Cas9-based genome engineering tools in Drosophila melanogaster. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2021; 180:85-121. [PMID: 33934839 DOI: 10.1016/bs.pmbts.2021.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Drosophila melanogaster has been used as a model organism for over a century. Mutant-based analyses have been used extensively to understand the genetic basis of different cellular processes, including development, neuronal function and diseases. Most of the earlier genetic mutants and specific tools were generated by random insertions and deletion strategies and then mapped to specific genomic loci. Since all genomic regions are not equally accessible to random mutations and insertions, many genes still remain uncharacterized. Low efficiency of targeted genomic manipulation approaches that rely on homologous recombination, and difficulty in generating resources for sequence-specific endonucleases, such as ZFNs (Zinc Finger Nucleases) and TALENs (Transcription Activator-Like Effector Nucleases), could not make these gene targeting techniques very popular. However, recently RNA directed DNA endonucleases, such as CRISPR-Cas, have transformed genome engineering owing to their comparative ease, versatility, and low expense. With the added advantage of preexisting genetic tools, CRISPR-Cas-based manipulations are being extensively used in Drosophila melanogaster and simultaneously being fine-tuned for specific experimental requirements. In this chapter, I will discuss various uses of CRISPR-Cas-based genetic engineering and specific design methods in Drosophila melanogaster. I will summarize various already available tools that are being utilized in conjunction with CRISPR-Cas technology to generate specific genetic manipulation and are being optimized to address specific questions. Finally, I will discuss the future directions of Drosophila genetics research and how CRISPR-Cas can be utilized to target specific questions, addressing which has not been possible thus far.
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Affiliation(s)
- Deepti Trivedi
- National Centre for Biological Sciences-TIFR, Bengaluru, India.
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12
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Trivedi D, CM V, Bisht K, Janardan V, Pandit A, Basak B, H S, Ramesh N, Raghu P. A genome engineering resource to uncover principles of cellular organization and tissue architecture by lipid signaling. eLife 2020; 9:e55793. [PMID: 33320085 PMCID: PMC7771963 DOI: 10.7554/elife.55793] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 12/14/2020] [Indexed: 12/14/2022] Open
Abstract
Phosphoinositides (PI) are key regulators of cellular organization in eukaryotes and genes that tune PI signaling are implicated in human disease mechanisms. Biochemical analyses and studies in cultured cells have identified a large number of proteins that can mediate PI signaling. However, the role of such proteins in regulating cellular processes in vivo and development in metazoans remains to be understood. Here, we describe a set of CRISPR-based genome engineering tools that allow the manipulation of each of these proteins with spatial and temporal control during metazoan development. We demonstrate the use of these reagents to deplete a set of 103 proteins individually in the Drosophila eye and identify several new molecules that control eye development. Our work demonstrates the power of this resource in uncovering the molecular basis of tissue homeostasis during normal development and in human disease biology.
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Affiliation(s)
- Deepti Trivedi
- National Centre for Biological Sciences-TIFR, GKVK CampusBangaloreIndia
| | - Vinitha CM
- National Centre for Biological Sciences-TIFR, GKVK CampusBangaloreIndia
| | - Karishma Bisht
- National Centre for Biological Sciences-TIFR, GKVK CampusBangaloreIndia
| | - Vishnu Janardan
- National Centre for Biological Sciences-TIFR, GKVK CampusBangaloreIndia
| | - Awadhesh Pandit
- National Centre for Biological Sciences-TIFR, GKVK CampusBangaloreIndia
| | - Bishal Basak
- National Centre for Biological Sciences-TIFR, GKVK CampusBangaloreIndia
| | - Shwetha H
- National Centre for Biological Sciences-TIFR, GKVK CampusBangaloreIndia
| | - Navyashree Ramesh
- National Centre for Biological Sciences-TIFR, GKVK CampusBangaloreIndia
| | - Padinjat Raghu
- National Centre for Biological Sciences-TIFR, GKVK CampusBangaloreIndia
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