1
|
Qin J, Yang T, Li K, Liu T, Zhang W. Pharyngeal mechanosensory neurons control food swallow in Drosophila melanogaster. eLife 2024; 12:RP88614. [PMID: 39630079 PMCID: PMC11616994 DOI: 10.7554/elife.88614] [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: 12/07/2024] Open
Abstract
As the early step of food ingestion, the swallow is under rigorous sensorimotor control. Nevertheless, the mechanisms underlying swallow control at a molecular and circuitry level remain largely unknown. Here, we find that mutation of the mechanotransduction channel genes nompC, Tmc, or piezo impairs the regular pumping rhythm of the cibarium during feeding of the fruit fly Drosophila melanogaster. A group of multi-dendritic mechanosensory neurons, which co-express the three channels, wrap the cibarium and are crucial for coordinating the filling and emptying of the cibarium. Inhibition of them causes difficulty in food emptying in the cibarium, while their activation leads to difficulty in cibarium filling. Synaptic and functional connections are detected between the pharyngeal mechanosensory neurons and the motor circuit that controls swallow. This study elucidates the role of mechanosensation in swallow, and provides insights for a better understanding of the neural basis of food swallow.
Collapse
Affiliation(s)
- Jierui Qin
- School of Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua UniversityBeijingChina
- Tsinghua-Peking Center for Life ScienceBeijingChina
| | - Tingting Yang
- School of Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua UniversityBeijingChina
- Tsinghua-Peking Center for Life ScienceBeijingChina
| | - Kexin Li
- School of Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua UniversityBeijingChina
- Tsinghua-Peking Center for Life ScienceBeijingChina
| | - Ting Liu
- School of Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua UniversityBeijingChina
| | - Wei Zhang
- Tsinghua-Peking Center for Life ScienceBeijingChina
| |
Collapse
|
2
|
Vincow ES, Thomas RE, Milstein G, Pareek G, Bammler TK, MacDonald J, Pallanck LJ. Glucocerebrosidase deficiency leads to neuropathology via cellular immune activation. PLoS Genet 2024; 20:e1011105. [PMID: 39527642 PMCID: PMC11581407 DOI: 10.1371/journal.pgen.1011105] [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: 12/12/2023] [Revised: 11/21/2024] [Accepted: 10/21/2024] [Indexed: 11/16/2024] Open
Abstract
Mutations in GBA (glucosylceramidase beta), which encodes the lysosomal enzyme glucocerebrosidase (GCase), are the strongest genetic risk factor for the neurodegenerative disorders Parkinson's disease (PD) and Lewy body dementia. Recent work has suggested that neuroinflammation may be an important factor in the risk conferred by GBA mutations. We therefore systematically tested the contributions of immune-related genes to neuropathology in a Drosophila model of GCase deficiency. We identified target immune factors via RNA-Seq and proteomics on heads from GCase-deficient flies, which revealed both increased abundance of humoral factors and increased macrophage activation. We then manipulated the identified immune factors and measured their effect on head protein aggregates, a hallmark of neurodegenerative disease. Genetic ablation of humoral (secreted) immune factors did not suppress the development of protein aggregation. By contrast, re-expressing Gba1b in activated macrophages suppressed head protein aggregation in Gba1b mutants and rescued their lifespan and behavioral deficits. Moreover, reducing the GCase substrate glucosylceramide in activated macrophages also ameliorated Gba1b mutant phenotypes. Taken together, our findings show that glucosylceramide accumulation due to GCase deficiency leads to macrophage activation, which in turn promotes the development of neuropathology.
Collapse
Affiliation(s)
- Evelyn S. Vincow
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Ruth E. Thomas
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Gillian Milstein
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Gautam Pareek
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Theo K. Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - James MacDonald
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Leo J. Pallanck
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| |
Collapse
|
3
|
Bankapalli K, Thomas RE, Vincow ES, Milstein G, Fisher LV, Pallanck LJ. A Drosophila model for mechanistic investigation of tau protein spread. Dis Model Mech 2024; 17:dmm050858. [PMID: 39350752 PMCID: PMC11463956 DOI: 10.1242/dmm.050858] [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: 04/22/2024] [Accepted: 08/09/2024] [Indexed: 10/09/2024] Open
Abstract
Brain protein aggregates are a hallmark of neurodegenerative disease. Previous work indicates that specific protein components of these aggregates are toxic, including tau (encoded by MAPT) in Alzheimer's disease and related tauopathies. Increasing evidence also indicates that these toxic proteins traffic between cells in a prion-like fashion, thereby spreading pathology from one brain region to another. However, the mechanisms involved in trafficking are poorly understood. We therefore developed a transgenic Drosophila model to facilitate rapid evaluation of candidate tau trafficking modifiers. Our model uses the bipartite Q system to drive co-expression of tau and GFP in the fly eye. We found age-dependent spread of tau into the brain, represented by detection of tau, but not of GFP. We also found that tau trafficking was attenuated upon inhibition of the endocytic factor dynamin (encoded by shi) or knockdown of glycogen synthase kinase-3β (GSK-3β, encoded by sgg). Further work revealed that dynamin promoted tau uptake in recipient tissues, whereas GSK-3β appeared to promote tau spread via direct phosphorylation of tau. Our robust and flexible system will promote the identification of tau-trafficking components involved in the pathogenesis of neurodegenerative diseases.
Collapse
Affiliation(s)
- Kondalarao Bankapalli
- Department of Genome Sciences, University of Washington, 3720 15th Avenue NE, Seattle, WA98195, USA
| | - Ruth E. Thomas
- Department of Genome Sciences, University of Washington, 3720 15th Avenue NE, Seattle, WA98195, USA
| | - Evelyn S. Vincow
- Department of Genome Sciences, University of Washington, 3720 15th Avenue NE, Seattle, WA98195, USA
| | - Gillian Milstein
- Department of Genome Sciences, University of Washington, 3720 15th Avenue NE, Seattle, WA98195, USA
| | - Laura V. Fisher
- Department of Genome Sciences, University of Washington, 3720 15th Avenue NE, Seattle, WA98195, USA
| | - Leo J. Pallanck
- Department of Genome Sciences, University of Washington, 3720 15th Avenue NE, Seattle, WA98195, USA
| |
Collapse
|
4
|
Bankapalli K, Thomas RE, Vincow ES, Milstein G, Fisher LV, Pallanck LJ. A Drosophila model for mechanistic investigation of tau protein spread. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.21.590466. [PMID: 38712083 PMCID: PMC11071371 DOI: 10.1101/2024.04.21.590466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Brain protein aggregates are a hallmark of neurodegenerative disease. Previous work indicates that specific protein components of these aggregates are toxic, including tau in Alzheimer's disease and related tauopathies. Increasing evidence also indicates that these toxic proteins traffic between cells in a prion-like fashion, thereby spreading pathology from one brain region to another. However, the mechanisms involved in trafficking are poorly understood. We therefore developed a transgenic Drosophila model to facilitate rapid evaluation of candidate tau trafficking modifiers. Our model uses the bipartite Q system to drive co-expression of tau and GFP in the fly eye. We find age-dependent tau spread into the brain, represented by detection of tau, but not GFP in the brain. We also found that tau trafficking was attenuated upon inhibition of the endocytic factor dynamin or the kinase glycogen synthase kinase-3β ( GSK-3β ). Further work revealed that dynamin promotes tau uptake in recipient tissues, whereas GSK-3β appears to promote tau spread via direct phosphorylation of tau. Our robust and flexible system will promote the identification of tau trafficking components involved in the pathogenesis of neurodegenerative diseases. SUMMARY STATEMENT The trafficking of toxic proteins in neurodegenerative disease is well-known but poorly understood. Our model will allow rapid and new insight into molecular mechanisms underlying this process.
Collapse
|
5
|
Zirin J, Jusiak B, Lopes R, Ewen-Campen B, Bosch JA, Risbeck A, Forman C, Villalta C, Hu Y, Perrimon N. Expanding the Drosophila toolkit for dual control of gene expression. eLife 2024; 12:RP94073. [PMID: 38569007 PMCID: PMC10990484 DOI: 10.7554/elife.94073] [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: 04/05/2024] Open
Abstract
The ability to independently control gene expression in two different tissues in the same animal is emerging as a major need, especially in the context of inter-organ communication studies. This type of study is made possible by technologies combining the GAL4/UAS and a second binary expression system such as the LexA system or QF system. Here, we describe a resource of reagents that facilitate combined use of the GAL4/UAS and a second binary system in various Drosophila tissues. Focusing on genes with well-characterized GAL4 expression patterns, we generated a set of more than 40 LexA-GAD and QF2 insertions by CRISPR knock-in and verified their tissue specificity in larvae. We also built constructs that encode QF2 and LexA-GAD transcription factors in a single vector. Following successful integration of this construct into the fly genome, FLP/FRT recombination is used to isolate fly lines that express only QF2 or LexA-GAD. Finally, using new compatible shRNA vectors, we evaluated both LexA and QF systems for in vivo gene knockdown and are generating a library of such RNAi fly lines as a community resource. Together, these LexA and QF system vectors and fly lines will provide a new set of tools for researchers who need to activate or repress two different genes in an orthogonal manner in the same animal.
Collapse
Affiliation(s)
- Jonathan Zirin
- Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Barbara Jusiak
- Department of Physiology and Biophysics, University of California, IrvineIrvineUnited States
| | - Raphael Lopes
- Department of Genetics, Harvard Medical SchoolBostonUnited States
| | | | - Justin A Bosch
- Department of Genetics, Harvard Medical SchoolBostonUnited States
| | | | - Corey Forman
- Department of Genetics, Harvard Medical SchoolBostonUnited States
| | | | - Yanhui Hu
- Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Norbert Perrimon
- Department of Genetics, Harvard Medical SchoolBostonUnited States
- Howard Hughes Medical InstituteBostonUnited States
| |
Collapse
|
6
|
Kockel L, Zhang V, Wang J, Gulick C, Laws ME, Rajan A, Lantz N, Asgarova A, Dai L, Garcia K, Kim C, Li M, Ordonez-Acosta P, Peng D, Shull H, Tse L, Wang Y, Yu W, Zhou Z, Rankin A, Park S, Kim SK. CRISPR/Cas9 gene editing in Drosophila via visual selection in a summer classroom. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.28.587232. [PMID: 38585736 PMCID: PMC10996655 DOI: 10.1101/2024.03.28.587232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
CRISPR/Cas9 methods are a powerful in vivo approach to edit the genome of Drosophila melanogaster. To convert existing Drosophila GAL4 lines to LexA driver lines in a secondary school classroom setting, we applied the CRISPR-based genetic approach to a collection of Gal4 'driver' lines. The integration of the yellow+ coat color marker into homology-assisted CRISPR knock-in (HACK) enabled visual selection of Gal4-to-LexA conversions using brightfield stereo-microscopy available in a broader set of standard classrooms. Here, we report the successful conversion of eleven Gal4 lines with expression in neuropeptide-expressing cells into corresponding, novel LexA drivers. The conversion was confirmed by LexA- and Gal4-specific GFP reporter gene expression. This curriculum was successfully implemented in a summer course running 16 hours/week for seven weeks. The modularity, flexibility, and compactness of this course should enable development of similar classes in secondary schools and undergraduate curricula, to provide opportunities for experience-based science instruction, and university-secondary school collaborations that simultaneously fulfill research needs in the community of science.
Collapse
Affiliation(s)
- Lutz Kockel
- Stanford University, Stanford, CA 94305, USA
- Dept. of Developmental Biology, Stanford University SOM, Stanford, CA 94305, USA
| | | | - Jenna Wang
- Phillips Exeter Academy, Exeter, NH 03833, USA
| | | | | | - Arjun Rajan
- Stanford University, Stanford, CA 94305, USA
- Dept. of Developmental Biology, Stanford University SOM, Stanford, CA 94305, USA
| | - Nicole Lantz
- The Lawrenceville School, Lawrenceville, NJ 08648, USA
| | | | - Lillian Dai
- Lexington High School, Lexington, MA 02421, USA
| | | | - Charlene Kim
- Busan International High School, Busan, South Korea
| | - Michelle Li
- Shenzhen Foreign Language School, Shenzhen, China
| | | | - Dongshen Peng
- University of North Carolina, Chapel Hill, NC 27599, USA
| | - Henry Shull
- Harvard University, Cambridge, MA 02138, USA
| | - Lauren Tse
- Hong Kong International School, Hong Kong, China
| | | | - Wenxin Yu
- Guangdong Country Garden School, Guangdong, China
| | - Zee Zhou
- Thomas Jefferson High School for Science and Technology, Alexandria, VA 22312, USA
| | - Anne Rankin
- Phillips Exeter Academy, Exeter, NH 03833, USA
| | - Sangbin Park
- Grier School, Tyrone, PA 16686, USA
- Dept. of Developmental Biology, Stanford University SOM, Stanford, CA 94305, USA
| | - Seung K Kim
- Stanford University, Stanford, CA 94305, USA
- Dept. of Developmental Biology, Stanford University SOM, Stanford, CA 94305, USA
- Lexington High School, Lexington, MA 02421, USA
- Stanford Diabetes Research Center, Stanford, CA 94305, USA
| |
Collapse
|
7
|
Zirin J, Jusiak B, Lopes R, Ewen-Campen B, Bosch JA, Risbeck A, Forman C, Villalta C, Hu Y, Perrimon N. Expanding the Drosophila toolkit for dual control of gene expression. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.15.553399. [PMID: 37645802 PMCID: PMC10461983 DOI: 10.1101/2023.08.15.553399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
The ability to independently control gene expression in two different tissues in the same animal is emerging as a major need, especially in the context of inter-organ communication studies. This type of study is made possible by technologies combining the GAL4/UAS and a second binary expression system such as the LexA-system or QF-system. Here, we describe a resource of reagents that facilitate combined use of the GAL4/UAS and a second binary system in various Drosophila tissues. Focusing on genes with well-characterizsed GAL4 expression patterns, we generated a set of more than 40 LexA-GAD and QF2 insertions by CRISPR knock-in and verified their tissue-specificity in larvae. We also built constructs that encode QF2 and LexA-GAD transcription factors in a single vector. Following successful integration of this construct into the fly genome, FLP/FRT recombination is used to isolate fly lines that express only QF2 or LexA-GAD. Finally, using new compatible shRNA vectors, we evaluated both LexA and QF systems for in vivo gene knockdown and are generating a library of such RNAi fly lines as a community resource. Together, these LexA and QF system vectors and fly lines will provide a new set of tools for researchers who need to activate or repress two different genes in an orthogonal manner in the same animal.
Collapse
|
8
|
Rankin AE, Fox E, Chisholm T, Lantz N, Rajan A, Phillips W, Griffin E, Harper J, Suhr C, Tan M, Wang J, Yang A, Kim ES, Ankrah NKA, Chakraborty P, Lam ACK, Laws ME, Lee J, Park KK, Wesel E, Covert PH, Kockel L, Park S, Kim SK. Simplified homology-assisted CRISPR for gene editing in Drosophila. G3 (BETHESDA, MD.) 2024; 14:jkad277. [PMID: 38058125 PMCID: PMC10849607 DOI: 10.1093/g3journal/jkad277] [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: 08/28/2023] [Revised: 08/28/2023] [Accepted: 10/29/2023] [Indexed: 12/08/2023]
Abstract
In vivo genome editing with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 generates powerful tools to study gene regulation and function. We revised the homology-assisted CRISPR knock-in method to convert Drosophila GAL4 lines to LexA lines using a new universal knock-in donor strain. A balancer chromosome-linked donor strain with both body color (yellow) and eye red fluorescent protein (RFP) expression markers simplified the identification of LexA knock-in using light or fluorescence microscopy. A second balancer chromosome-linked donor strain readily converted the second chromosome-linked GAL4 lines regardless of target location in the cis-chromosome but showed limited success for the third chromosome-linked GAL4 lines. We observed a consistent and robust expression of the yellow transgene in progeny harboring a LexA knock-in at diverse genomic locations. Unexpectedly, the expression of the 3xP3-RFP transgene in the "dual transgene" cassette was significantly increased compared with that of the original single 3xP3-RFP transgene cassette in all tested genomic locations. Using this improved screening approach, we generated 16 novel LexA lines; tissue expression by the derived LexA and originating GAL4 lines was similar or indistinguishable. In collaboration with 2 secondary school classes, we also established a systematic workflow to generate a collection of LexA lines from frequently used GAL4 lines.
Collapse
Affiliation(s)
| | - Elizabeth Fox
- The Lawrenceville School, Lawrenceville, NJ 08648, USA
| | | | - Nicole Lantz
- The Lawrenceville School, Lawrenceville, NJ 08648, USA
| | - Arjun Rajan
- Phillips Exeter Academy, Exeter, NH 03833, USA
| | | | | | | | | | - Max Tan
- Phillips Exeter Academy, Exeter, NH 03833, USA
| | - Jason Wang
- Phillips Exeter Academy, Exeter, NH 03833, USA
| | - Alana Yang
- Phillips Exeter Academy, Exeter, NH 03833, USA
| | - Ella S Kim
- Phillips Exeter Academy, Exeter, NH 03833, USA
| | | | | | | | | | - Jackson Lee
- The Lawrenceville School, Lawrenceville, NJ 08648, USA
| | - Kyle K Park
- The Lawrenceville School, Lawrenceville, NJ 08648, USA
| | - Emily Wesel
- Stanford University, Stanford, CA 94305, USA
| | | | - Lutz Kockel
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sangbin Park
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Seung K Kim
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
- Stanford Diabetes Research Center, Stanford, CA 94305, USA
| |
Collapse
|
9
|
Vincow ES, Thomas RE, Milstein G, Pareek G, Bammler T, MacDonald J, Pallanck L. Glucocerebrosidase deficiency leads to neuropathology via cellular immune activation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.13.571406. [PMID: 38168223 PMCID: PMC10760128 DOI: 10.1101/2023.12.13.571406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Mutations in GBA (glucosylceramidase beta), which encodes the lysosomal enzyme glucocerebrosidase (GCase), are the strongest genetic risk factor for the neurodegenerative disorders Parkinson's disease (PD) and Lewy body dementia. Recent work has suggested that neuroinflammation may be an important factor in the risk conferred by GBA mutations. We therefore systematically tested the contributions of immune-related genes to neuropathology in a Drosophila model of GCase deficiency. We identified target immune factors via RNA-Seq and proteomics on heads from GCase-deficient flies, which revealed both increased abundance of humoral factors and increased macrophage activation. We then manipulated the identified immune factors and measured their effect on head protein aggregates, a hallmark of neurodegenerative disease. Genetic ablation of humoral (secreted) immune factors did not suppress the development of protein aggregation. By contrast, re-expressing Gba1b in activated macrophages suppressed head protein aggregation in Gba1b mutants and rescued their lifespan and behavioral deficits. Moreover, reducing the GCase substrate glucosylceramide in activated macrophages also ameliorated Gba1b mutant phenotypes. Taken together, our findings show that glucosylceramide accumulation due to GCase deficiency leads to macrophage activation, which in turn promotes the development of neuropathology.
Collapse
Affiliation(s)
- Evelyn S. Vincow
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Ruth E. Thomas
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Gillian Milstein
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Gautam Pareek
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Theo Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - James MacDonald
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Leo Pallanck
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| |
Collapse
|
10
|
Weiner AT, Cho B, Suyama K, Axelrod JD. Cell autonomous polarization by the planar cell polarity signaling pathway. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.26.559449. [PMID: 37808631 PMCID: PMC10557733 DOI: 10.1101/2023.09.26.559449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Planar Cell Polarity (PCP) signaling polarizes epithelial cells in a plane orthogonal to their apical-basal axis. A core PCP signaling module both generates molecular asymmetry within cells and coordinates the direction of polarization between neighboring cells. Two subcomplexes of core proteins segregate to opposite sides of the cell, defining a polarity axis. Homodimers of the atypical cadherin Flamingo are thought to be the scaffold upon which these subcomplexes assemble and are required for intercellular polarity signaling. The central role for Flamingo homodimers in scaffolding and intercellular communication suggests that cells in which intercellular signaling via Flamingo is disabled should fail to polarize. We show that cells lacking Flamingo, or bearing a truncated Flamingo that cannot homodimerize do in fact polarize. Cell polarization requires both positive and negative feedback, and in a multicellular tissue, feedback might involve both intracellular and intercellular pathways. We identify positive and negative feedback pathways that operate cell autonomously to drive polarization.
Collapse
Affiliation(s)
- Alexis T Weiner
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Bomsoo Cho
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kaye Suyama
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jeffrey D Axelrod
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| |
Collapse
|
11
|
Nagai H, Nagai LAE, Tasaki S, Nakato R, Umetsu D, Kuranaga E, Miura M, Nakajima Y. Nutrient-driven dedifferentiation of enteroendocrine cells promotes adaptive intestinal growth in Drosophila. Dev Cell 2023; 58:1764-1781.e10. [PMID: 37689060 DOI: 10.1016/j.devcel.2023.08.022] [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: 07/22/2022] [Revised: 05/05/2023] [Accepted: 08/16/2023] [Indexed: 09/11/2023]
Abstract
Post-developmental organ resizing improves organismal fitness under constantly changing nutrient environments. Although stem cell abundance is a fundamental determinant of adaptive resizing, our understanding of its underlying mechanisms remains primarily limited to the regulation of stem cell division. Here, we demonstrate that nutrient fluctuation induces dedifferentiation in the Drosophila adult midgut to drive adaptive intestinal growth. From lineage tracing and single-cell RNA sequencing, we identify a subpopulation of enteroendocrine (EE) cells that convert into functional intestinal stem cells (ISCs) in response to dietary glucose and amino acids by activating the JAK-STAT pathway. Genetic ablation of EE-derived ISCs severely impairs ISC expansion and midgut growth despite the retention of resident ISCs, and in silico modeling further indicates that EE dedifferentiation enables an efficient increase in the midgut cell number while maintaining epithelial cell composition. Our findings identify a physiologically induced dedifferentiation that ensures ISC expansion during adaptive organ growth in concert with nutrient conditions.
Collapse
Affiliation(s)
- Hiroki Nagai
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan; Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Miyagi 980-0845, Japan.
| | | | - Sohei Tasaki
- Graduate School of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Ryuichiro Nakato
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Daiki Umetsu
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-0845, Japan; Graduate School of Science, Osaka University, Osaka 560-0043, Japan
| | - Erina Kuranaga
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-0845, Japan
| | - Masayuki Miura
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yuichiro Nakajima
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan; Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Miyagi 980-0845, Japan; Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-0845, Japan.
| |
Collapse
|
12
|
Parisi MJ, Aimino MA, Mosca TJ. A conditional strategy for cell-type-specific labeling of endogenous excitatory synapses in Drosophila. CELL REPORTS METHODS 2023; 3:100477. [PMID: 37323572 PMCID: PMC10261928 DOI: 10.1016/j.crmeth.2023.100477] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 02/28/2023] [Accepted: 04/19/2023] [Indexed: 06/17/2023]
Abstract
Chemical neurotransmission occurs at specialized contacts where neurotransmitter release machinery apposes neurotransmitter receptors to underlie circuit function. A series of complex events underlies pre- and postsynaptic protein recruitment to neuronal connections. To better study synaptic development in individual neurons, we need cell-type-specific strategies to visualize endogenous synaptic proteins. Although presynaptic strategies exist, postsynaptic proteins remain less studied because of a paucity of cell-type-specific reagents. To study excitatory postsynapses with cell-type specificity, we engineered dlg1[4K], a conditionally labeled marker of Drosophila excitatory postsynaptic densities. With binary expression systems, dlg1[4K] labels central and peripheral postsynapses in larvae and adults. Using dlg1[4K], we find that distinct rules govern postsynaptic organization in adult neurons, multiple binary expression systems can concurrently label pre- and postsynapse in a cell-type-specific manner, and neuronal DLG1 can sometimes localize presynaptically. These results validate our strategy for conditional postsynaptic labeling and demonstrate principles of synaptic organization.
Collapse
Affiliation(s)
- Michael J. Parisi
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Michael A. Aimino
- 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
| |
Collapse
|
13
|
Konopka JK, Task D, Poinapen D, Potter CJ. Neurogenetic identification of mosquito sensory neurons. iScience 2023; 26:106690. [PMID: 37182106 PMCID: PMC10172775 DOI: 10.1016/j.isci.2023.106690] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 03/06/2023] [Accepted: 04/13/2023] [Indexed: 05/16/2023] Open
Abstract
Anopheles mosquitoes, as vectors for the malaria parasite, are a global threat to human health. To find and bite a human, they utilize neurons within their sensory appendages. However, the identity and quantification of sensory appendage neurons are lacking. Here we use a neurogenetic approach to label all neurons in Anopheles coluzzii mosquitoes. We utilize the homology assisted CRISPR knock-in (HACK) approach to generate a T2A-QF2w knock-in of the synaptic gene bruchpilot. We use a membrane-targeted GFP reporter to visualize the neurons in the brain and to quantify neurons in all major chemosensory appendages (antenna, maxillary palp, labella, tarsi, and ovipositor). By comparing labeling of brp>GFP and Orco>GFP mosquitoes, we predict the extent of neurons expressing ionotropic receptors (IRs) or other chemosensory receptors. This work introduces a valuable genetic tool for the functional analysis of Anopheles mosquito neurobiology and initiates characterization of the sensory neurons that guide mosquito behavior.
Collapse
Affiliation(s)
- Joanna K. Konopka
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Darya Task
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Danny Poinapen
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Christopher J. Potter
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Corresponding author
| |
Collapse
|
14
|
Karuparti S, Yeung AT, Wang B, Guicardi PF, Han C. A toolkit for converting Gal4 into LexA and Flippase transgenes in Drosophila. G3 (BETHESDA, MD.) 2023; 13:jkad003. [PMID: 36617215 PMCID: PMC9997562 DOI: 10.1093/g3journal/jkad003] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/01/2022] [Accepted: 01/02/2023] [Indexed: 01/09/2023]
Abstract
Drosophila has been a powerful model system for biological studies due to the wide range of genetic tools established for it. Among these tools, Gal4 is the most abundant, offering unparalleled tissue and developmental stage specificity for gene manipulation. In comparison, other genetic reagents are far fewer in choices. Here we present a genetic toolkit for converting Gal4 strains into LexA and Flippase transgenes through simple genetic crosses and fluorescence screening. We demonstrate the proof-of-principle by converting ten Gal4 lines that exhibit diverse tissue specificities and examined the activity patterns of the converted LexA and Flippase lines. Gal4-to-LexA and Flp conversion is fast and convenient and should greatly expand the choices of LexA and Flp for binary expression and FRT-based mosaic analysis, respectively, in Drosophila.
Collapse
Affiliation(s)
- Sasidhar Karuparti
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Ann T Yeung
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Bei Wang
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Pedro F Guicardi
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Chun Han
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
15
|
Raji JI, Konopka JK, Potter CJ. A spatial map of antennal-expressed ionotropic receptors in the malaria mosquito. Cell Rep 2023; 42:112101. [PMID: 36773296 PMCID: PMC10412736 DOI: 10.1016/j.celrep.2023.112101] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/22/2022] [Accepted: 01/26/2023] [Indexed: 02/12/2023] Open
Abstract
The mosquito's antenna represents its main olfactory appendage for detecting volatile chemical cues from the environment. Whole-mount fluorescence in situ hybridization of ionotropic receptors (IRs) expressed in the antennae reveals that the antenna might be divisible into proximal and distal functional domains. The number of IR-positive cells appear stereotyped within each antennal segment (flagellomere). Highly expressed odor-tuning IRs exhibit distinct co-localization patterns with the IR coreceptors Ir8a, Ir25a, and Ir76b that might predict their functional properties. Genetic knockin and in vivo functional imaging of IR41c-expressing neurons indicate both odor-induced activation and inhibition in response to select amine compounds. Targeted mutagenesis of IR41c does not abolish behavioral responses to the amine compounds. Our study provides a comprehensive map of IR-expressing neurons in the main olfactory appendage of mosquitoes. These findings show organizing principles of Anopheles IR-expressing neurons, which might underlie their functional contribution to the detection of behaviorally relevant odors.
Collapse
Affiliation(s)
- Joshua I Raji
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Joanna K Konopka
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Christopher J Potter
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
16
|
Marmor-Kollet N, Berkun V, Cummings G, Keren-Shaul H, David E, Addadi Y, Schuldiner O. Actin-dependent astrocytic infiltration is a key step for axon defasciculation during remodeling. Cell Rep 2023; 42:112117. [PMID: 36790930 PMCID: PMC9989824 DOI: 10.1016/j.celrep.2023.112117] [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: 12/15/2021] [Revised: 10/17/2022] [Accepted: 01/28/2023] [Indexed: 02/16/2023] Open
Abstract
Astrocytes are essential for synapse formation, maturation, and plasticity; however, their function during developmental neuronal remodeling is largely unknown. To identify astrocytic molecules required for axon pruning of mushroom body (MB) γ neurons in Drosophila, we profiled astrocytes before (larva) and after (adult) remodeling. Focusing on genes enriched in larval astrocytes, we identified 12 astrocytic genes that are required for axon pruning, including the F-actin regulators Actin-related protein 2/3 complex, subunit 1 (Arpc1) and formin3 (form3). Interestingly, perturbing astrocytic actin dynamics does not affect their gross morphology, migration, or transforming growth factor β (TGF-β) secretion. In contrast, actin dynamics is required for astrocyte infiltration into the axon bundle at the onset of pruning. Remarkably, decreasing axonal adhesion facilitates infiltration by Arpc1 knockdown (KD) astrocytes and promotes axon pruning. Conversely, increased axonal adhesion reduces lobe infiltration by wild-type (WT) astrocytes. Together, our findings suggest that actin-dependent astrocytic infiltration is a key step in axon pruning, thus promoting our understanding of neuron-glia interactions during remodeling.
Collapse
Affiliation(s)
- Neta Marmor-Kollet
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Victoria Berkun
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Gideon Cummings
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Hadas Keren-Shaul
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Eyal David
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yoseph Addadi
- Weizmann Institute of Science, Life Sciences Core Facilities, Rehovot 7610001, Israel
| | - Oren Schuldiner
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel.
| |
Collapse
|
17
|
Hedgehog is relayed through dynamic heparan sulfate interactions to shape its gradient. Nat Commun 2023; 14:758. [PMID: 36765094 PMCID: PMC9918555 DOI: 10.1038/s41467-023-36450-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 01/27/2023] [Indexed: 02/12/2023] Open
Abstract
Cellular differentiation is directly determined by concentration gradients of morphogens. As a central model for gradient formation during development, Hedgehog (Hh) morphogens spread away from their source to direct growth and pattern formation in Drosophila wing and eye discs. What is not known is how extracellular Hh spread is achieved and how it translates into precise gradients. Here we show that two separate binding areas located on opposite sides of the Hh molecule can interact directly and simultaneously with two heparan sulfate (HS) chains to temporarily cross-link the chains. Mutated Hh lacking one fully functional binding site still binds HS but shows reduced HS cross-linking. This, in turn, impairs Hhs ability to switch between both chains in vitro and results in striking Hh gradient hypomorphs in vivo. The speed and propensity of direct Hh switching between HS therefore shapes the Hh gradient, revealing a scalable design principle in morphogen-patterned tissues.
Collapse
|
18
|
Terradas G, Bennett JB, Li Z, Marshall JM, Bier E. Genetic conversion of a split-drive into a full-drive element. Nat Commun 2023; 14:191. [PMID: 36635291 PMCID: PMC9837192 DOI: 10.1038/s41467-022-35044-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 11/16/2022] [Indexed: 01/13/2023] Open
Abstract
The core components of CRISPR-based gene drives, Cas9 and guide RNA (gRNA), either can be linked within a self-contained single cassette (full gene-drive, fGD) or be provided in two separate elements (split gene-drive, sGD), the latter offering greater control options. We previously engineered split systems that could be converted genetically into autonomous full drives. Here, we examine such dual systems inserted at the spo11 locus that are recoded to restore gene function and thus organismic fertility. Despite minimal differences in transmission efficiency of the sGD or fGD drive elements in single generation crosses, the reconstituted spo11 fGD cassette surprisingly exhibits slower initial drive kinetics than the unlinked sGD element in multigenerational cage studies, but then eventually catches up to achieve a similar level of final introduction. These unexpected kinetic behaviors most likely reflect differing transient fitness costs associated with individuals co-inheriting Cas9 and gRNA transgenes during the drive process.
Collapse
Affiliation(s)
- Gerard Terradas
- Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093, USA.,Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, 92093, USA.,Department of Entomology, The Center for Infectious Disease Dynamics, and the Huck Institutes for the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Jared B Bennett
- Biophysics Graduate Group, Division of Biological Sciences, College of Letters and Science, University of California, Berkeley, CA, 94720, USA
| | - Zhiqian Li
- Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093, USA.,Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, 92093, USA
| | - John M Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA, 94720, USA.,Innovative Genomics Institute, Berkeley, CA, 94720, USA
| | - Ethan Bier
- Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093, USA. .,Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, 92093, USA.
| |
Collapse
|
19
|
Jiao W, Spreemann G, Ruchti E, Banerjee S, Vernon S, Shi Y, Stowers RS, Hess K, McCabe BD. Intact Drosophila central nervous system cellular quantitation reveals sexual dimorphism. eLife 2022; 11:74968. [PMID: 35801638 PMCID: PMC9270032 DOI: 10.7554/elife.74968] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 06/09/2022] [Indexed: 12/15/2022] Open
Abstract
Establishing with precision the quantity and identity of the cell types of the brain is a prerequisite for a detailed compendium of gene and protein expression in the central nervous system (CNS). Currently, however, strict quantitation of cell numbers has been achieved only for the nervous system of Caenorhabditis elegans. Here, we describe the development of a synergistic pipeline of molecular genetic, imaging, and computational technologies designed to allow high-throughput, precise quantitation with cellular resolution of reporters of gene expression in intact whole tissues with complex cellular constitutions such as the brain. We have deployed the approach to determine with exactitude the number of functional neurons and glia in the entire intact larval Drosophila CNS, revealing fewer neurons and more glial cells than previously predicted. We also discover an unexpected divergence between the sexes at this juvenile developmental stage, with the female CNS having significantly more neurons than that of males. Topological analysis of our data establishes that this sexual dimorphism extends to deeper features of CNS organisation. We additionally extended our analysis to quantitate the expression of voltage-gated potassium channel family genes throughout the CNS and uncover substantial differences in abundance. Our methodology enables robust and accurate quantification of the number and positioning of cells within intact organs, facilitating sophisticated analysis of cellular identity, diversity, and gene expression characteristics.
Collapse
Affiliation(s)
- Wei Jiao
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Gard Spreemann
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Evelyne Ruchti
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Soumya Banerjee
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Samuel Vernon
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Ying Shi
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - R Steven Stowers
- Department of Microbiology and Cell Biology, Montana State University
| | - Kathryn Hess
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Brian D McCabe
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| |
Collapse
|
20
|
Roy S, Juste SS, Sneider M, Auradkar A, Klanseck C, Li Z, Julio AHF, Lopez del Amo V, Bier E, Guichard A. Cas9/Nickase-induced allelic conversion by homologous chromosome-templated repair in Drosophila somatic cells. SCIENCE ADVANCES 2022; 8:eabo0721. [PMID: 35776792 PMCID: PMC10883370 DOI: 10.1126/sciadv.abo0721] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Repair of double-strand breaks (DSBs) in somatic cells is primarily accomplished by error-prone nonhomologous end joining and less frequently by precise homology-directed repair preferentially using the sister chromatid as a template. Here, a Drosophila system performs efficient somatic repair of both DSBs and single-strand breaks (SSBs) using intact sequences from the homologous chromosome in a process we refer to as homologous chromosome-templated repair (HTR). Unexpectedly, HTR-mediated allelic conversion at the white locus was more efficient (40 to 65%) in response to SSBs induced by Cas9-derived nickases D10A or H840A than to DSBs induced by fully active Cas9 (20 to 30%). Repair phenotypes elicited by Nickase versus Cas9 differ in both developmental timing (late versus early stages, respectively) and the production of undesired mutagenic events (rare versus frequent). Nickase-mediated HTR represents an efficient and unanticipated mechanism for allelic correction, with far-reaching potential applications in the field of gene editing.
Collapse
Affiliation(s)
- Sitara Roy
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Sara Sanz Juste
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Marketta Sneider
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Ankush Auradkar
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Carissa Klanseck
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Zhiqian Li
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Alison Henrique Ferreira Julio
- Instituto de Ciências Biomédicas (ICB), Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-902 RJ, Brazil
| | - Victor Lopez del Amo
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Ethan Bier
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
- Tata Institute for Genetics and Society-UCSD, La Jolla, CA 92093-0335, USA
| | - Annabel Guichard
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| |
Collapse
|
21
|
Sainz de la Maza D, Hof-Michel S, Phillimore L, Bökel C, Amoyel M. Cell-cycle exit and stem cell differentiation are coupled through regulation of mitochondrial activity in the Drosophila testis. Cell Rep 2022; 39:110774. [PMID: 35545055 PMCID: PMC9350557 DOI: 10.1016/j.celrep.2022.110774] [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: 02/22/2021] [Revised: 02/21/2022] [Accepted: 04/12/2022] [Indexed: 11/27/2022] Open
Abstract
Whereas stem and progenitor cells proliferate to maintain tissue homeostasis, fully differentiated cells exit the cell cycle. How cell identity and cell-cycle state are coordinated during differentiation is still poorly understood. The Drosophila testis niche supports germline stem cells and somatic cyst stem cells (CySCs). CySCs give rise to post-mitotic cyst cells, providing a tractable model to study the links between stem cell identity and proliferation. We show that, while cell-cycle progression is required for CySC self-renewal, the E2f1/Dp transcription factor is dispensable for self-renewal but instead must be silenced by the Drosophila retinoblastoma homolog, Rbf, to permit differentiation. Continued E2f1/Dp activity inhibits the expression of genes important for mitochondrial activity. Furthermore, promoting mitochondrial biogenesis rescues the differentiation of CySCs with ectopic E2f1/Dp activity but not their cell-cycle exit. In sum, E2f1/Dp coordinates cell-cycle progression with stem cell identity by regulating the metabolic state of CySCs. CycE is critical for CySC self-renewal E2f/Dp does not act in self-renewal but must be silenced for differentiation E2f/Dp inhibits increases in oxidative metabolism involved in normal differentiation Increased mitochondrial biogenesis rescues differentiation of E2f/Dp-active cells
Collapse
Affiliation(s)
- Diego Sainz de la Maza
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Silvana Hof-Michel
- Department of Developmental Genetics, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
| | - Lee Phillimore
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Christian Bökel
- Department of Developmental Genetics, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany.
| | - Marc Amoyel
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK.
| |
Collapse
|
22
|
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: 60] [Impact Index Per Article: 30.0] [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.
Collapse
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
| |
Collapse
|
23
|
Xu DC, Wang L, Yamada KM, Baena-Lopez LA. Non-apoptotic activation of Drosophila caspase-2/9 modulates JNK signaling, the tumor microenvironment, and growth of wound-like tumors. Cell Rep 2022; 39:110718. [PMID: 35443185 PMCID: PMC9082238 DOI: 10.1016/j.celrep.2022.110718] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 02/15/2022] [Accepted: 03/31/2022] [Indexed: 11/23/2022] Open
Abstract
Resistance to apoptosis due to caspase deregulation is considered one of the main hallmarks of cancer. However, the discovery of novel non-apoptotic caspase functions has revealed unknown intricacies about the interplay between these enzymes and tumor progression. To investigate this biological problem, we capitalized on a Drosophila tumor model with human relevance based on the simultaneous overactivation of the EGFR and the JAK/STAT signaling pathways. Our data indicate that widespread non-apoptotic activation of initiator caspases limits JNK signaling and facilitates cell fate commitment in these tumors, thus preventing the overgrowth and exacerbation of malignant features of transformed cells. Intriguingly, caspase activity also reduces the presence of macrophage-like cells with tumor-promoting properties in the tumor microenvironment. These findings assign tumor-suppressing activities to caspases independent of apoptosis, while providing molecular details to better understand the contribution of these enzymes to tumor progression.
Collapse
Affiliation(s)
- Derek Cui Xu
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4370, USA; Sir William Dunn School of Pathology, University of Oxford, Oxford, Oxfordshire OX1 3RE, UK
| | - Li Wang
- Sir William Dunn School of Pathology, University of Oxford, Oxford, Oxfordshire OX1 3RE, UK
| | - Kenneth M Yamada
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4370, USA.
| | | |
Collapse
|
24
|
Verkuijl SAN, Ang JXD, Alphey L, Bonsall MB, Anderson MAE. The Challenges in Developing Efficient and Robust Synthetic Homing Endonuclease Gene Drives. Front Bioeng Biotechnol 2022; 10:856981. [PMID: 35419354 PMCID: PMC8996256 DOI: 10.3389/fbioe.2022.856981] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/04/2022] [Indexed: 11/13/2022] Open
Abstract
Making discrete and precise genetic changes to wild populations has been proposed as a means of addressing some of the world's most pressing ecological and public health challenges caused by insect pests. Technologies that would allow this, such as synthetic gene drives, have been under development for many decades. Recently, a new generation of programmable nucleases has dramatically accelerated technological development. CRISPR-Cas9 has improved the efficiency of genetic engineering and has been used as the principal effector nuclease in different gene drive inheritance biasing mechanisms. Of these nuclease-based gene drives, homing endonuclease gene drives have been the subject of the bulk of research efforts (particularly in insects), with many different iterations having been developed upon similar core designs. We chart the history of homing gene drive development, highlighting the emergence of challenges such as unintended repair outcomes, "leaky" expression, and parental deposition. We conclude by discussing the progress made in developing strategies to increase the efficiency of homing endonuclease gene drives and mitigate or prevent unintended outcomes.
Collapse
Affiliation(s)
- Sebald A. N. Verkuijl
- Arthropod Genetics, The Pirbright Institute, Pirbright, United Kingdom
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Joshua X. D. Ang
- Arthropod Genetics, The Pirbright Institute, Pirbright, United Kingdom
| | - Luke Alphey
- Arthropod Genetics, The Pirbright Institute, Pirbright, United Kingdom
| | | | | |
Collapse
|
25
|
Chang KR, Tsao DD, Bennett C, Wang E, Floyd JF, Tay ASY, Greenwald E, Kim ES, Griffin C, Morse E, Chisholm T, Rankin AE, Baena-Lopez LA, Lantz N, Fox E, Kockel L, Kim SK, Park S. Transgenic Drosophila lines for LexA-dependent gene and growth regulation. G3 (BETHESDA, MD.) 2022; 12:jkac018. [PMID: 35100369 PMCID: PMC8895989 DOI: 10.1093/g3journal/jkac018] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 01/05/2022] [Indexed: 11/12/2022]
Abstract
Conditional expression of short hairpin RNAs with binary genetic systems is an indispensable tool for studying gene function. Addressing mechanisms underlying cell-cell communication in vivo benefits from simultaneous use of 2 independent gene expression systems. To complement the abundance of existing Gal4/UAS-based resources in Drosophila, we and others have developed LexA/LexAop-based genetic tools. Here, we describe experimental and pedagogical advances that promote the efficient conversion of Drosophila Gal4 lines to LexA lines, and the generation of LexAop-short hairpin RNA lines to suppress gene function. We developed a CRISPR/Cas9-based knock-in system to replace Gal4 coding sequences with LexA, and a LexAop-based short hairpin RNA expression vector to achieve short hairpin RNA-mediated gene silencing. We demonstrate the use of these approaches to achieve targeted genetic loss-of-function in multiple tissues. We also detail our development of secondary school curricula that enable students to create transgenic flies, thereby magnifying the production of well-characterized LexA/LexAop lines for the scientific community. The genetic tools and teaching methods presented here provide LexA/LexAop resources that complement existing resources to study intercellular communication coordinating metazoan physiology and development.
Collapse
Affiliation(s)
- Kathleen R Chang
- Stanford University, Stanford, CA 94305, USA
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Deborah D Tsao
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Celine Bennett
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Elaine Wang
- The Lawrenceville School, Lawrenceville, NJ 08648, USA
| | - Jax F Floyd
- The Lawrenceville School, Lawrenceville, NJ 08648, USA
| | | | - Emily Greenwald
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ella S Kim
- Phillips Exeter Academy, Exeter, NH 03833, USA
| | | | | | | | | | | | - Nicole Lantz
- The Lawrenceville School, Lawrenceville, NJ 08648, USA
| | - Elizabeth Fox
- The Lawrenceville School, Lawrenceville, NJ 08648, USA
| | - Lutz Kockel
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Seung K Kim
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Departments of Medicine and of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
- Stanford Diabetes Research Center, Stanford, CA 94305, USA
| | - Sangbin Park
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| |
Collapse
|
26
|
Stachowski K, Norris A, Potter D, Wysocki V, Foster M. Mechanisms of Cre recombinase synaptic complex assembly and activation illuminated by Cryo-EM. Nucleic Acids Res 2022; 50:1753-1769. [PMID: 35104890 PMCID: PMC8860596 DOI: 10.1093/nar/gkac032] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 01/04/2022] [Accepted: 01/12/2022] [Indexed: 12/15/2022] Open
Abstract
Cre recombinase selectively recognizes DNA and prevents non-specific DNA cleavage through an orchestrated series of assembly intermediates. Cre recombines two loxP DNA sequences featuring a pair of palindromic recombinase binding elements and an asymmetric spacer region, by assembly of a tetrameric synaptic complex, cleavage of an opposing pair of strands, and formation of a Holliday junction intermediate. We used Cre and loxP variants to isolate the monomeric Cre-loxP (54 kDa), dimeric Cre2-loxP (110 kDa), and tetrameric Cre4-loxP2 assembly intermediates, and determined their structures using cryo-EM to resolutions of 3.9, 4.5 and 3.2 Å, respectively. Progressive and asymmetric bending of the spacer region along the assembly pathway enables formation of increasingly intimate interfaces between Cre protomers and illuminates the structural bases of biased loxP strand cleavage order and half-the-sites activity. Application of 3D variability analysis to the tetramer data reveals constrained conformational sampling along the pathway between protomer activation and Holliday junction isomerization. These findings underscore the importance of protein and DNA flexibility in Cre-mediated site selection, controlled activation of alternating protomers, the basis for biased strand cleavage order, and recombination efficiency. Such considerations may advance development of site-specific recombinases for use in gene editing applications.
Collapse
Affiliation(s)
- Kye Stachowski
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Andrew S Norris
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Devante Potter
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Vicki H Wysocki
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Mark P Foster
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| |
Collapse
|
27
|
Chou YH, Yang CJ, Huang HW, Liou NF, Panganiban MR, Luginbuhl D, Yin Y, Taisz I, Liang L, Jefferis GSXE, Luo L. Mating-driven variability in olfactory local interneuron wiring. SCIENCE ADVANCES 2022; 8:eabm7723. [PMID: 35179957 PMCID: PMC8856614 DOI: 10.1126/sciadv.abm7723] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Variations in neuronal connectivity occur widely in nervous systems from invertebrates to mammals. Yet, it is unclear how neuronal variability originates, to what extent and at what time scales it exists, and what functional consequences it might carry. To assess inter- and intraindividual neuronal variability, it would be ideal to analyze the same identified neuron across different brain hemispheres and individuals. Here, using genetic labeling and electron microscopy connectomics, we show that an identified inhibitory olfactory local interneuron, TC-LN, exhibits extraordinary variability in its glomerular innervation patterns. Moreover, TC-LN's innervation of the VL2a glomerulus, which processes food signals and modulates mating behavior, is sexually dimorphic, is influenced by female's courtship experience, and correlates with food intake in mated females. Mating also affects output connectivity of TC-LN to specific local interneurons. We propose that mating-associated variability of TC-LNs regulates how food odor is interpreted by an inhibitory network to modulate feeding.
Collapse
Affiliation(s)
- Ya-Hui Chou
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
- Neuroscience Program of Academia Sinica, Academia Sinica, Taipei 11529, Taiwan
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei 10617, Taiwan
| | - Chi-Jen Yang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Hao-Wei Huang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Nan-Fu Liou
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | | | - David Luginbuhl
- Howard Hughes Medical Institute and Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Yijie Yin
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - Istvan Taisz
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Liang Liang
- Howard Hughes Medical Institute and Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Gregory S. X. E. Jefferis
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Liqun Luo
- Howard Hughes Medical Institute and Department of Biology, Stanford University, Stanford, CA 94305, USA
| |
Collapse
|
28
|
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.
Collapse
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.
| |
Collapse
|
29
|
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.
Collapse
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.
| |
Collapse
|
30
|
Marr E, Potter CJ. Base Editing of Somatic Cells Using CRISPR-Cas9 in Drosophila. CRISPR J 2021; 4:836-845. [PMID: 34813372 PMCID: PMC8744452 DOI: 10.1089/crispr.2021.0062] [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] [Indexed: 11/13/2022] Open
Abstract
Cas9 and a guide RNA (gRNA) function to target specific genomic loci for generation of a double-stranded break. Catalytic dead versions of Cas9 (dCas9) no longer cause double-stranded breaks and instead can serve as molecular scaffolds to target additional enzymatic proteins to specific genomic loci. To generate mutations in selected genomic residues, dCas9 can be used for genomic base editing by fusing a cytidine deaminase (CD) to induce C > T (or G>A) mutations at targeted sites. In this study, we test base editing in Drosophila by expressing a transgenic Drosophila base editor (based on the mammalian BE2) that consists of a fusion protein of CD, dCas9, and uracil glycosylase inhibitor. We utilized transgenic lines expressing gRNAs along with pan-tissue expression of the Drosophila base editor (Actin5C-BE2) and found high rates of base editing at multiple targeted loci in the 20 bp target sequence. Highest rates of conversion of C > T were found in positions 3-9 of the gRNA-targeted site, with conversion reaching ∼100% of targeted DNA in somatic tissues. Surprisingly, the simultaneous use of two gRNAs targeting a genomic region spaced ∼50 bp apart led to mutations between the two gRNA targets, implicating a method to broaden the available sites accessible to targeting. These results indicate base editing is efficient in Drosophila, and could be used to induce point mutations at select loci.
Collapse
Affiliation(s)
- Elizabeth Marr
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Christopher J. Potter
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
31
|
Yang T, Yuan Z, Liu C, Liu T, Zhang W. A neural circuit integrates pharyngeal sensation to control feeding. Cell Rep 2021; 37:109983. [PMID: 34758309 DOI: 10.1016/j.celrep.2021.109983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 08/20/2021] [Accepted: 10/20/2021] [Indexed: 11/18/2022] Open
Abstract
Swallowing is an essential step of eating and drinking. However, how the quality of a food bolus is sensed by pharyngeal neurons is largely unknown. Here we find that mechanical receptors along the Drosophila pharynx are required for control of meal size, especially for food of high viscosity. The mechanical force exerted by the bolus passing across the pharynx is detected by neurons expressing the mechanotransduction channel NOMPC (no mechanoreceptor potential C) and is relayed, together with gustatory information, to IN1 neurons in the subesophageal zone (SEZ) of the brain. IN1 (ingestion neurons) neurons act directly upstream of a group of peptidergic neurons that encode satiety. Prolonged activation of IN1 neurons suppresses feeding. IN1 neurons receive inhibition from DSOG1 (descending subesophageal neurons) neurons, a group of GABAergic neurons that non-selectively suppress feeding. Our results reveal the function of pharyngeal mechanoreceptors and their downstream neural circuits in the control of food ingestion.
Collapse
Affiliation(s)
- Tingting Yang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Zixuan Yuan
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Chenxi Liu
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Ting Liu
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Wei Zhang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
| |
Collapse
|
32
|
Girard JR, Goins LM, Vuu DM, Sharpley MS, Spratford CM, Mantri SR, Banerjee U. Paths and pathways that generate cell-type heterogeneity and developmental progression in hematopoiesis. eLife 2021; 10:e67516. [PMID: 34713801 PMCID: PMC8610493 DOI: 10.7554/elife.67516] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 10/22/2021] [Indexed: 12/29/2022] Open
Abstract
Mechanistic studies of Drosophila lymph gland hematopoiesis are limited by the availability of cell-type-specific markers. Using a combination of bulk RNA-Seq of FACS-sorted cells, single-cell RNA-Seq, and genetic dissection, we identify new blood cell subpopulations along a developmental trajectory with multiple paths to mature cell types. This provides functional insights into key developmental processes and signaling pathways. We highlight metabolism as a driver of development, show that graded Pointed expression allows distinct roles in successive developmental steps, and that mature crystal cells specifically express an alternate isoform of Hypoxia-inducible factor (Hif/Sima). Mechanistically, the Musashi-regulated protein Numb facilitates Sima-dependent non-canonical, and inhibits canonical, Notch signaling. Broadly, we find that prior to making a fate choice, a progenitor selects between alternative, biologically relevant, transitory states allowing smooth transitions reflective of combinatorial expressions rather than stepwise binary decisions. Increasingly, this view is gaining support in mammalian hematopoiesis.
Collapse
Affiliation(s)
- Juliet R Girard
- Department of Molecular, Cell and Developmental Biology, University of California, Los AngelesLos AngelesUnited States
| | - Lauren M Goins
- Department of Molecular, Cell and Developmental Biology, University of California, Los AngelesLos AngelesUnited States
| | - Dung M Vuu
- Department of Molecular, Cell and Developmental Biology, University of California, Los AngelesLos AngelesUnited States
| | - Mark S Sharpley
- Department of Molecular, Cell and Developmental Biology, University of California, Los AngelesLos AngelesUnited States
| | - Carrie M Spratford
- Department of Molecular, Cell and Developmental Biology, University of California, Los AngelesLos AngelesUnited States
| | - Shreya R Mantri
- Department of Molecular, Cell and Developmental Biology, University of California, Los AngelesLos AngelesUnited States
| | - Utpal Banerjee
- Department of Molecular, Cell and Developmental Biology, University of California, Los AngelesLos AngelesUnited States
- Molecular Biology Institute, University of California, Los AngelesLos AngelesUnited States
- Department of Biological Chemistry, University of California, Los AngelesLos AngelesUnited States
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los AngelesLos AngelesUnited States
| |
Collapse
|
33
|
Intravital imaging strategy FlyVAB reveals the dependence of Drosophila enteroblast differentiation on the local physiology. Commun Biol 2021; 4:1223. [PMID: 34697396 PMCID: PMC8546075 DOI: 10.1038/s42003-021-02757-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 10/06/2021] [Indexed: 02/05/2023] Open
Abstract
Aging or injury in Drosophila intestine promotes intestinal stem cell (ISC) proliferation and enteroblast (EB) differentiation. However, the manner the local physiology couples with dynamic EB differentiation assessed by traditional lineage tracing method is still vague. Therefore, we developed a 3D-printed platform “FlyVAB” for intravital imaging strategy that enables the visualization of the Drosophila posterior midgut at a single cell level across the ventral abdomen cuticle. Using ISCs in young and healthy midgut and enteroendocrine cells in age-associated hyperplastic midgut as reference coordinates, we traced ISC-EB-enterocyte lineages with Notch signaling reporter for multiple days. Our results reveal a “differentiation-poised” EB status correlated with slow ISC divisions and a “differentiation-activated” EB status correlated with ISC hyperplasia and rapid EB to enterocyte differentiation. Our FlyVAB imaging strategy opens the door to long-time intravital imaging of intestinal epithelium. Tang et. al. demonstrate a 3Dprinted platform, FlyVAB, for intravital imaging and visualization of the Drosophila posterior midgut at a single-cell level. This method enables tracking of the stem cell lineage in the midgut of the flies constantly for up to 10 days.
Collapse
|
34
|
Tumor-derived MMPs regulate cachexia in a Drosophila cancer model. Dev Cell 2021; 56:2664-2680.e6. [PMID: 34473940 DOI: 10.1016/j.devcel.2021.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 07/09/2021] [Accepted: 08/12/2021] [Indexed: 12/14/2022]
Abstract
Cachexia, the wasting syndrome commonly observed in advanced cancer patients, accounts for up to one-third of cancer-related mortalities. We have established a Drosophila larval model of organ wasting whereby epithelial overgrowth in eye-antennal discs leads to wasting of the adipose tissue and muscles. The wasting is associated with fat-body remodeling and muscle detachment and is dependent on tumor-secreted matrix metalloproteinase 1 (Mmp1). Mmp1 can both modulate TGFβ signaling in the fat body and disrupt basement membrane (BM)/extracellular matrix (ECM) protein localization in both the fat body and the muscle. Inhibition of TGFβ signaling or Mmps in the fat body/muscle using a QF2-QUAS binary expression system rescues muscle wasting in the presence of tumor. Altogether, our study proposes that tumor-derived Mmps are central mediators of organ wasting in cancer cachexia.
Collapse
|
35
|
Banerjee S, Vernon S, Jiao W, Choi BJ, Ruchti E, Asadzadeh J, Burri O, Stowers RS, McCabe BD. Miniature neurotransmission is required to maintain Drosophila synaptic structures during ageing. Nat Commun 2021; 12:4399. [PMID: 34285221 PMCID: PMC8292383 DOI: 10.1038/s41467-021-24490-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 06/22/2021] [Indexed: 11/27/2022] Open
Abstract
The decline of neuronal synapses is an established feature of ageing accompanied by the diminishment of neuronal function, and in the motor system at least, a reduction of behavioural capacity. Here, we have investigated Drosophila motor neuron synaptic terminals during ageing. We observed cumulative fragmentation of presynaptic structures accompanied by diminishment of both evoked and miniature neurotransmission occurring in tandem with reduced motor ability. Through discrete manipulation of each neurotransmission modality, we find that miniature but not evoked neurotransmission is required to maintain presynaptic architecture and that increasing miniature events can both preserve synaptic structures and prolong motor ability during ageing. Our results establish that miniature neurotransmission, formerly viewed as an epiphenomenon, is necessary for the long-term stability of synaptic connections. Synaptic structures disintegrate and fragment as ageing progresses. Here the authors find that miniature neurotransmission is required to maintain adult motor synapse structures in Drosophila and that increasing miniature events can preserve motor ability during ageing.
Collapse
Affiliation(s)
- Soumya Banerjee
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology Lausanne, Lausanne, Switzerland
| | - Samuel Vernon
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology Lausanne, Lausanne, Switzerland
| | - Wei Jiao
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology Lausanne, Lausanne, Switzerland
| | - Ben Jiwon Choi
- Department of Biology, New York University, New York, USA
| | - Evelyne Ruchti
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology Lausanne, Lausanne, Switzerland
| | - Jamshid Asadzadeh
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology Lausanne, Lausanne, Switzerland
| | - Olivier Burri
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology Lausanne, Lausanne, Switzerland
| | - R Steven Stowers
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, USA
| | - Brian D McCabe
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology Lausanne, Lausanne, Switzerland.
| |
Collapse
|
36
|
Kim SK, Tsao DD, Suh GSB, Miguel-Aliaga I. Discovering signaling mechanisms governing metabolism and metabolic diseases with Drosophila. Cell Metab 2021; 33:1279-1292. [PMID: 34139200 PMCID: PMC8612010 DOI: 10.1016/j.cmet.2021.05.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/30/2021] [Accepted: 05/25/2021] [Indexed: 12/18/2022]
Abstract
There has been rapid growth in the use of Drosophila and other invertebrate systems to dissect mechanisms governing metabolism. New assays and approaches to physiology have aligned with superlative genetic tools in fruit flies to provide a powerful platform for posing new questions, or dissecting classical problems in metabolism and disease genetics. In multiple examples, these discoveries exploit experimental advantages as-yet unavailable in mammalian systems. Here, we illustrate how fly studies have addressed long-standing questions in three broad areas-inter-organ signaling through hormonal or neural mechanisms governing metabolism, intestinal interoception and feeding, and the cellular and signaling basis of sexually dimorphic metabolism and physiology-and how these findings relate to human (patho)physiology. The imaginative application of integrative physiology and related approaches in flies to questions in metabolism is expanding, and will be an engine of discovery, revealing paradigmatic features of metabolism underlying human diseases and physiological equipoise in health.
Collapse
Affiliation(s)
- Seung K Kim
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Medicine (Endocrinology), Stanford University School of Medicine, Stanford, CA 94305, USA; Stanford Diabetes Research Center, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Deborah D Tsao
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Greg S B Suh
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea.
| | - Irene Miguel-Aliaga
- MRC London Institute of Medical Sciences, London, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK.
| |
Collapse
|
37
|
Koreman GT, Xu Y, Hu Q, Zhang Z, Allen SE, Wolfner MF, Wang B, Han C. Upgraded CRISPR/Cas9 tools for tissue-specific mutagenesis in Drosophila. Proc Natl Acad Sci U S A 2021; 118:e2014255118. [PMID: 33782117 PMCID: PMC8040800 DOI: 10.1073/pnas.2014255118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
CRISPR/Cas9 has emerged as a powerful technology for tissue-specific mutagenesis. However, tissue-specific CRISPR/Cas9 tools currently available in Drosophila remain deficient in three significant ways. First, many existing gRNAs are inefficient, such that further improvements of gRNA expression constructs are needed for more efficient and predictable mutagenesis in both somatic and germline tissues. Second, it has been difficult to label mutant cells in target tissues with current methods. Lastly, application of tissue-specific mutagenesis at present often relies on Gal4-driven Cas9, which hampers the flexibility and effectiveness of the system. Here, we tackle these deficiencies by building upon our previous CRISPR-mediated tissue-restricted mutagenesis (CRISPR-TRiM) tools. First, we significantly improved gRNA efficiency in somatic tissues by optimizing multiplexed gRNA design. Similarly, we also designed efficient dual-gRNA vectors for the germline. Second, we developed methods to positively and negatively label mutant cells in tissue-specific mutagenesis by incorporating co-CRISPR reporters into gRNA expression vectors. Lastly, we generated genetic reagents for convenient conversion of existing Gal4 drivers into tissue-specific Cas9 lines based on homology-assisted CRISPR knock-in. In this way, we expand the choices of Cas9 for CRISPR-TRiM analysis to broader tissues and developmental stages. Overall, our upgraded CRISPR/Cas9 tools make tissue-specific mutagenesis more versatile, reliable, and effective in Drosophila These improvements may be also applied to other model systems.
Collapse
Affiliation(s)
- Gabriel T Koreman
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Yineng Xu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Qinan Hu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Zijing Zhang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Sarah E Allen
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Mariana F Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Bei Wang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853;
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Chun Han
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853;
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| |
Collapse
|
38
|
Terradas G, Buchman AB, Bennett JB, Shriner I, Marshall JM, Akbari OS, Bier E. Inherently confinable split-drive systems in Drosophila. Nat Commun 2021; 12:1480. [PMID: 33674604 PMCID: PMC7935863 DOI: 10.1038/s41467-021-21771-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 02/05/2021] [Indexed: 02/06/2023] Open
Abstract
CRISPR-based gene-drive systems, which copy themselves via gene conversion mediated by the homology-directed repair (HDR) pathway, have the potential to revolutionize vector control. However, mutant alleles generated by the competing non-homologous end-joining (NHEJ) pathway, resistant to Cas9 cleavage, can interrupt the spread of gene-drive elements. We hypothesized that drives targeting genes essential for viability or reproduction also carrying recoded sequences that restore endogenous gene functionality should benefit from dominantly-acting maternal clearance of NHEJ alleles combined with recessive Mendelian culling processes. Here, we test split gene-drive (sGD) systems in Drosophila melanogaster that are inserted into essential genes required for viability (rab5, rab11, prosalpha2) or fertility (spo11). In single generation crosses, sGDs copy with variable efficiencies and display sex-biased transmission. In multigenerational cage trials, sGDs follow distinct drive trajectories reflecting their differential tendencies to induce target chromosome damage and/or lethal/sterile mosaic Cas9-dependent phenotypes, leading to inherently confinable drive outcomes. NHEJ alleles and Cas9 remnants after a gene drive introduction are scientific and public concerns. Here, the authors use split drives with recoded rescue elements to target essential genes and minimize the appearance of NHEJ alleles while also leaving no trace of Cas9.
Collapse
Affiliation(s)
- Gerard Terradas
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, USA.,Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, USA
| | - Anna B Buchman
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, USA
| | - Jared B Bennett
- Biophysics Graduate Group, Division of Biological Sciences, College of Letters and Science, University of California, Berkeley, CA, USA
| | - Isaiah Shriner
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, USA
| | - John M Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA, USA.,Innovative Genomics Institute, Berkeley, CA, USA
| | - Omar S Akbari
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, USA
| | - Ethan Bier
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, USA. .,Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, USA.
| |
Collapse
|
39
|
Kandul NP, Liu J, Bennett JB, Marshall JM, Akbari OS. A confinable home-and-rescue gene drive for population modification. eLife 2021; 10:e65939. [PMID: 33666174 PMCID: PMC7968924 DOI: 10.7554/elife.65939] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 03/04/2021] [Indexed: 12/11/2022] Open
Abstract
Homing-based gene drives, engineered using CRISPR/Cas9, have been proposed to spread desirable genes throughout populations. However, invasion of such drives can be hindered by the accumulation of resistant alleles. To limit this obstacle, we engineer a confinable population modification home-and-rescue (HomeR) drive in Drosophila targeting an essential gene. In our experiments, resistant alleles that disrupt the target gene function were recessive lethal and therefore disadvantaged. We demonstrate that HomeR can achieve an increase in frequency in population cage experiments, but that fitness costs due to the Cas9 insertion limit drive efficacy. Finally, we conduct mathematical modeling comparing HomeR to contemporary gene drive architectures for population modification over wide ranges of fitness costs, transmission rates, and release regimens. HomeR could potentially be adapted to other species, as a means for safe, confinable, modification of wild populations.
Collapse
Affiliation(s)
- Nikolay P Kandul
- Section of Cell and Developmental Biology, University of California, San DiegoSan DiegoUnited States
| | - Junru Liu
- Section of Cell and Developmental Biology, University of California, San DiegoSan DiegoUnited States
| | - Jared B Bennett
- Biophysics Graduate Group, University of California, BerkeleyBerkeleyUnited States
| | - John M Marshall
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, BerkeleyBerkeleyUnited States
| | - Omar S Akbari
- Section of Cell and Developmental Biology, University of California, San DiegoSan DiegoUnited States
| |
Collapse
|
40
|
Driesschaert B, Mergan L, Temmerman L. Conditional gene expression in invertebrate animal models. J Genet Genomics 2021; 48:14-31. [PMID: 33814307 DOI: 10.1016/j.jgg.2021.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/11/2020] [Accepted: 01/08/2021] [Indexed: 10/22/2022]
Abstract
A mechanistic understanding of biology requires appreciating spatiotemporal aspects of gene expression and its functional implications. Conditional expression allows for (ir)reversible switching of genes on or off, with the potential of spatial and/or temporal control. This provides a valuable complement to the more often used constitutive gene (in)activation through mutagenesis, providing tools to answer a wider array of research questions across biological disciplines. Spatial and/or temporal control are granted primarily by (combinations of) specific promoters, temperature regimens, compound addition, or illumination. The use of such genetic tool kits is particularly widespread in invertebrate animal models because they can be applied to study biological processes in short time frames and on large scales, using organisms amenable to easy genetic manipulation. Recent years witnessed an exciting expansion and optimization of such tools, of which we provide a comprehensive overview and discussion regarding their use in invertebrates. The mechanism, applicability, benefits, and drawbacks of each of the systems, as well as further developments to be expected in the foreseeable future, are highlighted.
Collapse
Affiliation(s)
- Brecht Driesschaert
- Animal Physiology and Neurobiology, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59 - Box 2465, B-3000 Leuven, Belgium
| | - Lucas Mergan
- Animal Physiology and Neurobiology, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59 - Box 2465, B-3000 Leuven, Belgium
| | - Liesbet Temmerman
- Animal Physiology and Neurobiology, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59 - Box 2465, B-3000 Leuven, Belgium.
| |
Collapse
|
41
|
Allen SE, Koreman GT, Sarkar A, Wang B, Wolfner MF, Han C. Versatile CRISPR/Cas9-mediated mosaic analysis by gRNA-induced crossing-over for unmodified genomes. PLoS Biol 2021; 19:e3001061. [PMID: 33444322 PMCID: PMC7837743 DOI: 10.1371/journal.pbio.3001061] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 01/26/2021] [Accepted: 01/04/2021] [Indexed: 12/26/2022] Open
Abstract
Mosaic animals have provided the platform for many fundamental discoveries in developmental biology, cell biology, and other fields. Techniques to produce mosaic animals by mitotic recombination have been extensively developed in Drosophila melanogaster but are less common for other laboratory organisms. Here, we report mosaic analysis by gRNA-induced crossing-over (MAGIC), a new technique for generating mosaic animals based on DNA double-strand breaks produced by CRISPR/Cas9. MAGIC efficiently produces mosaic clones in both somatic tissues and the germline of Drosophila. Further, by developing a MAGIC toolkit for 1 chromosome arm, we demonstrate the method's application in characterizing gene function in neural development and in generating fluorescently marked clones in wild-derived Drosophila strains. Eliminating the need to introduce recombinase-recognition sites into the genome, this simple and versatile system simplifies mosaic analysis in Drosophila and can in principle be applied in any organism that is compatible with CRISPR/Cas9.
Collapse
Affiliation(s)
- Sarah E. Allen
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Gabriel T. Koreman
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
| | - Ankita Sarkar
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
| | - Bei Wang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
| | - Mariana F. Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Chun Han
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
| |
Collapse
|
42
|
Kaur P, Kibat C, Teo E, Gruber J, Mathuru A, Tolwinski ANS. Use of Optogenetic Amyloid-β to Monitor Protein Aggregation in Drosophila melanogaster, Danio rerio and Caenorhabditis elegans. Bio Protoc 2020; 10:e3856. [PMID: 33659494 PMCID: PMC7842303 DOI: 10.21769/bioprotoc.3856] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/20/2020] [Accepted: 11/22/2020] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's Disease (AD) has long been associated with accumulation of extracellular amyloid plaques (Aβ) originating from the Amyloid Precursor Protein. Plaques have, however, been discovered in healthy individuals and not all AD brains show plaques, suggesting that extracellular Aβ aggregates may play a smaller role than anticipated. One limitation to studying Aβ peptide in vivo during disease progression is the inability to induce aggregation in a controlled manner. We developed an optogenetic method to induce Aβ aggregation and tested its biological influence in three model organisms-D. melanogaster, C. elegans and D. rerio. We generated a fluorescently labeled, optogenetic Aβ peptide that oligomerizes rapidly in vivo in the presence of blue light in all organisms. Here, we detail the procedures for expressing this fusion protein in animal models, investigating the effects on the nervous system using time lapse light-sheet microscopy, and performing metabolic assays to measure changes due to intracellular Aβ aggregation. This method, employing optogenetics to study the pathology of AD, allows spatial and temporal control in vivo that cannot be achieved by any other method at present.
Collapse
Affiliation(s)
| | - Caroline Kibat
- Institute of Molecular and Cell Biology (IMCB), Singapore
| | - Emelyne Teo
- Science Division, Yale-NUS College, Singapore
| | - Jan Gruber
- Science Division, Yale-NUS College, Singapore
- Department of Biochemistry, National University of Singapore, Singapore
| | - Ajay Mathuru
- Science Division, Yale-NUS College, Singapore
- Department of Physiology, YLL School of Medicine, National University of Singapore, Singapore
- Institute of Molecular and Cell Biology (IMCB), Singapore
| | | |
Collapse
|
43
|
Ariyapala IS, Holsopple JM, Popodi EM, Hartwick DG, Kahsai L, Cook KR, Sokol NS. Identification of Split-GAL4 Drivers and Enhancers That Allow Regional Cell Type Manipulations of the Drosophila melanogaster Intestine. Genetics 2020; 216:891-903. [PMID: 32988987 PMCID: PMC7768249 DOI: 10.1534/genetics.120.303625] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 09/24/2020] [Indexed: 12/30/2022] Open
Abstract
The Drosophila adult midgut is a model epithelial tissue composed of a few major cell types with distinct regional identities. One of the limitations to its analysis is the lack of tools to manipulate gene expression based on these regional identities. To overcome this obstacle, we applied the intersectional split-GAL4 system to the adult midgut and report 653 driver combinations that label cells by region and cell type. We first identified 424 split-GAL4 drivers with midgut expression from ∼7300 drivers screened, and then evaluated the expression patterns of each of these 424 when paired with three reference drivers that report activity specifically in progenitor cells, enteroendocrine cells, or enterocytes. We also evaluated a subset of the drivers expressed in progenitor cells for expression in enteroblasts using another reference driver. We show that driver combinations can define novel cell populations by identifying a driver that marks a distinct subset of enteroendocrine cells expressing genes usually associated with progenitor cells. The regional cell type patterns associated with the entire set of driver combinations are documented in a freely available website, providing information for the design of thousands of additional driver combinations to experimentally manipulate small subsets of intestinal cells. In addition, we show that intestinal enhancers identified with the split-GAL4 system can confer equivalent expression patterns on other transgenic reporters. Altogether, the resource reported here will enable more precisely targeted gene expression for studying intestinal processes, epithelial cell functions, and diseases affecting self-renewing tissues.
Collapse
Affiliation(s)
| | - Jessica M Holsopple
- Department of Biology, Indiana University, Bloomington, Indiana 47405
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Ellen M Popodi
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Dalton G Hartwick
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Lily Kahsai
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Kevin R Cook
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Nicholas S Sokol
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| |
Collapse
|
44
|
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: 34] [Impact Index Per Article: 8.5] [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.
Collapse
Affiliation(s)
| | | | | | - Benjamin H. White
- Laboratory of Molecular Biology, National Institute of Mental Health, NIH, Bethesda, MD, United States
| |
Collapse
|
45
|
Abstract
Precise genetic manipulation of specific cell types or tissues to pinpoint gene function requirement is a critical step in studies aimed at unraveling the intricacies of organismal physiology. Drosophila researchers heavily rely on the UAS/Gal4/Gal80 system for tissue-specific manipulations; however, it is often unclear whether the reported Gal4 expression patterns are indeed specific to the tissue of interest such that experimental results are not confounded by secondary sites of Gal4 expression. Here, we surveyed the expression patterns of commonly used Gal4 drivers in adult Drosophila female tissues under optimal conditions and found that multiple drivers have unreported secondary sites of expression beyond their published cell type/tissue expression pattern. These results underscore the importance of thoroughly characterizing Gal4 tools as part of a rigorous experimental design that avoids potential misinterpretation of results as we strive for understanding how the function of a specific gene/pathway in one tissue contributes to whole-body physiology.
Collapse
|
46
|
Wang P, Jia Y, Liu T, Jan YN, Zhang W. Visceral Mechano-sensing Neurons Control Drosophila Feeding by Using Piezo as a Sensor. Neuron 2020; 108:640-650.e4. [PMID: 32910893 DOI: 10.1016/j.neuron.2020.08.017] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 05/24/2020] [Accepted: 08/18/2020] [Indexed: 12/16/2022]
Abstract
Animal feeding is controlled by external sensory cues and internal metabolic states. Does it also depend on enteric neurons that sense mechanical cues to signal fullness of the digestive tract? Here, we identify a group of piezo-expressing neurons innervating the Drosophila crop (the fly equivalent of the stomach) that monitor crop volume to avoid food overconsumption. These neurons reside in the pars intercerebralis (PI), a neuro-secretory center in the brain involved in homeostatic control, and express insulin-like peptides with well-established roles in regulating food intake and metabolism. Piezo knockdown in these neurons of wild-type flies phenocopies the food overconsumption phenotype of piezo-null mutant flies. Conversely, expression of either fly Piezo or mammalian Piezo1 in these neurons of piezo-null mutants suppresses the overconsumption phenotype. Importantly, Piezo+ neurons at the PI are activated directly by crop distension, thus conveying a rapid satiety signal along the "brain-gut axis" to control feeding.
Collapse
Affiliation(s)
- Pingping Wang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, 100084, China
| | - Yinjun Jia
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, 100084, China
| | - Ting Liu
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, 100084, China
| | - Yuh-Nung Jan
- Howard Hughes Medical Institute, Departments of Physiology, Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Wei Zhang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, 100084, China.
| |
Collapse
|
47
|
Liu C, Zhang B, Zhang L, Yang T, Zhang Z, Gao Z, Zhang W. A neural circuit encoding mating states tunes defensive behavior in Drosophila. Nat Commun 2020; 11:3962. [PMID: 32770059 PMCID: PMC7414864 DOI: 10.1038/s41467-020-17771-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 07/20/2020] [Indexed: 01/07/2023] Open
Abstract
Social context can dampen or amplify the perception of touch, and touch in turn conveys nuanced social information. However, the neural mechanism behind social regulation of mechanosensation is largely elusive. Here we report that fruit flies exhibit a strong defensive response to mechanical stimuli to their wings. In contrast, virgin female flies being courted by a male show a compromised defensive response to the stimuli, but following mating the response is enhanced. This state-dependent switch is mediated by a functional reconfiguration of a neural circuit labelled with the Tmc-L gene in the ventral nerve cord. The circuit receives excitatory inputs from peripheral mechanoreceptors and coordinates the defensive response. While male cues suppress it via a doublesex (dsx) neuronal pathway, mating sensitizes it by stimulating a group of uterine neurons and consequently activating a leucokinin-dependent pathway. Such a modulation is crucial for the balance between defense against body contacts and sexual receptivity. Wing touching induces a defensive response in D. melanogaster. Here, the authors show that female flies change the defensive response during courtship and after mating. This switch is mediated by functional reconfiguration of a neural circuit in the ventral nerve cord.
Collapse
Affiliation(s)
- Chenxi Liu
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, 100084, Beijing, China
| | - Bei Zhang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, 100084, Beijing, China
| | - Liwei Zhang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, 100084, Beijing, China
| | - Tingting Yang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, 100084, Beijing, China
| | - Zhewei Zhang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, 100084, Beijing, China
| | - Zihua Gao
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, 100084, Beijing, China
| | - Wei Zhang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, 100084, Beijing, China.
| |
Collapse
|
48
|
Zhang L, Yu J, Guo X, Wei J, Liu T, Zhang W. Parallel Mechanosensory Pathways Direct Oviposition Decision-Making in Drosophila. Curr Biol 2020; 30:3075-3088.e4. [PMID: 32649914 DOI: 10.1016/j.cub.2020.05.076] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/09/2020] [Accepted: 05/22/2020] [Indexed: 10/23/2022]
Abstract
Female Drosophila choose their sites for oviposition with deliberation. Female flies employ sensitive chemosensory systems to evaluate chemical cues for egg-laying substrates, but how they determine the physical quality of an oviposition patch remains largely unexplored. Here we report that flies evaluate the stiffness of the substrate surface using sensory structures on their appendages. The TRPV family channel Nanchung is required for the detection of all stiffness ranges tested, whereas two other proteins, Inactive and DmPiezo, interact with Nanchung to sense certain spectral ranges of substrate stiffness differences. Furthermore, Tmc is critical for sensing subtle differences in substrate stiffness. The Tmc channel is expressed in distinct patterns on the labellum and legs and the mechanosensory inputs coordinate to direct the final decision making for egg laying. Our study thus reveals the machinery for deliberate egg-laying decision making in fruit flies to ensure optimal survival for their offspring.
Collapse
Affiliation(s)
- Liwei Zhang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research at Tsinghua, Tsinghua University, Beijing 100084, China.
| | - Jie Yu
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research at Tsinghua, Tsinghua University, Beijing 100084, China
| | - Xuan Guo
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research at Tsinghua, Tsinghua University, Beijing 100084, China
| | - Jianhuan Wei
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research at Tsinghua, Tsinghua University, Beijing 100084, China
| | - Ting Liu
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research at Tsinghua, Tsinghua University, Beijing 100084, China
| | - Wei Zhang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research at Tsinghua, Tsinghua University, Beijing 100084, China.
| |
Collapse
|
49
|
Chen HM, Yao X, Ren Q, Chang CC, Liu LY, Miyares RL, Lee T. Enhanced Golic+: highly effective CRISPR gene targeting and transgene HACKing in Drosophila. Development 2020; 147:dev181974. [PMID: 32467238 DOI: 10.1242/dev.181974] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 05/04/2020] [Indexed: 11/20/2022]
Abstract
Gene targeting is an incredibly valuable technique. Sometimes, however, it can also be extremely challenging for various intrinsic reasons (e.g. low target accessibility or nature/extent of gene modification). To bypass these barriers, we designed a transgene-based system in Drosophila that increases the number of independent gene targeting events while at the same time enriching for correctly targeted progeny. Unfortunately, with particularly challenging gene targeting experiments, our original design yielded numerous false positives. Here, we deliver a much-improved technique, named Enhanced Golic+ (E-Golic+). E-Golic+ incorporates genetic modifications to tighten lethality-based selection while simultaneously boosting efficiency. With E-Golic+, we easily achieve previously unattainable gene targeting. Additionally, we built an E-Golic+-based, high-efficiency genetic pipeline for transgene swapping. We demonstrate its utility by transforming GAL4 enhancer-trap lines into tissue-specific Cas9-expressing lines. Given the superior efficiency, specificity and scalability, E-Golic+ promises to expedite development of additional sophisticated genetic/genomic tools in Drosophila.
Collapse
Affiliation(s)
- Hui-Min Chen
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Xiaohao Yao
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Qingzhong Ren
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Chuan-Chie Chang
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Ling-Yu Liu
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Rosa Linda Miyares
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Tzumin Lee
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| |
Collapse
|
50
|
Kim JH, Singh M, Pan G, Lopez A, Zito N, Bosse B, Ye B. Frameshift mutations of YPEL3 alter the sensory circuit function in Drosophila. Dis Model Mech 2020; 13:dmm042390. [PMID: 32461240 PMCID: PMC7286299 DOI: 10.1242/dmm.042390] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 03/31/2020] [Indexed: 11/22/2022] Open
Abstract
A frameshift mutation in Yippee-like (YPEL) 3 was recently found from a rare human disorder with peripheral neurological conditions including hypotonia and areflexia. The YPEL gene family is highly conserved from yeast to human, but its members' functions are poorly defined. Moreover, the pathogenicity of the human YPEL3 variant is completely unknown. We generated a Drosophila model of human YPEL3 variant and a genetic null allele of Drosophila homolog of YPEL3 (referred to as dYPEL3). Gene-trap analysis suggests that dYPEL3 is predominantly expressed in subsets of neurons, including larval nociceptors. Analysis of chemical nociception induced by allyl-isothiocyanate (AITC), a natural chemical stimulant, revealed reduced nociceptive responses in both dYPEL3 frameshift and null mutants. Subsequent circuit analysis showed reduced activation of second-order neurons (SONs) in the pathway without affecting nociceptor activation upon AITC treatment. Although the gross axonal and dendritic development of nociceptors was unaffected, the synaptic contact between nociceptors and SONs was decreased by the dYPEL3 mutations. Furthermore, expressing dYPEL3 in larval nociceptors rescued the behavioral deficit in dYPEL3 frameshift mutants, suggesting a presynaptic origin of the deficit. Together, these findings suggest that the frameshift mutation results in YPEL3 loss of function and may cause neurological conditions by weakening synaptic connections through presynaptic mechanisms.
Collapse
Affiliation(s)
- Jung Hwan Kim
- Department of Biology, University of Nevada, Reno, Reno, NV 89557, USA
| | - Monika Singh
- Department of Biology, University of Nevada, Reno, Reno, NV 89557, USA
| | - Geng Pan
- Life Sciences Institute and Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Adrian Lopez
- Department of Biology, University of Nevada, Reno, Reno, NV 89557, USA
| | - Nicholas Zito
- Department of Biology, University of Nevada, Reno, Reno, NV 89557, USA
| | - Benjamin Bosse
- Department of Biology, University of Nevada, Reno, Reno, NV 89557, USA
| | - Bing Ye
- Life Sciences Institute and Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| |
Collapse
|