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Butsch TJ, Dubuisson O, Johnson AE, Bohnert KA. A meiotic switch in lysosome activity supports spermatocyte development in young flies but collapses with age. iScience 2022; 25:104382. [PMID: 35620438 PMCID: PMC9126793 DOI: 10.1016/j.isci.2022.104382] [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: 09/11/2021] [Revised: 12/01/2021] [Accepted: 05/05/2022] [Indexed: 11/12/2022] Open
Abstract
Gamete development ultimately influences animal fertility. Identifying mechanisms that direct gametogenesis, and how they deteriorate with age, may inform ways to combat infertility. Recently, we found that lysosomes acidify during oocyte maturation in Caenorhabditis elegans, suggesting that a meiotic switch in lysosome activity promotes female germ-cell health. Using Drosophila melanogaster, we report that lysosomes likewise acidify in male germ cells during meiosis. Inhibiting lysosomes in young-male testes causes E-cadherin accumulation and loss of germ-cell partitioning membranes. Notably, analogous changes occur naturally during aging; in older testes, a reduction in lysosome acidity precedes E-cadherin accumulation and membrane dissolution, suggesting one potential cause of age-related spermatocyte abnormalities. Consistent with lysosomes governing the production of mature sperm, germ cells with homozygous-null mutations in lysosome-acidifying machinery fail to survive through meiosis. Thus, lysosome activation is entrained to meiotic progression in developing sperm, as in oocytes, and lysosomal dysfunction may instigate male reproductive aging. Lysosomes acidify at the mitotic-meiotic transition in the testis Acidic lysosomes support germ-cell membrane stability Lysosome acidity naturally declines in the aging male germline Lysosome acidification is required for mature sperm production
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Stark K, Crowe O, Lewellyn L. Precise levels of the Drosophila adaptor protein Dreadlocks maintain the size and stability of germline ring canals. J Cell Sci 2021; 134:238107. [PMID: 33912915 PMCID: PMC8106954 DOI: 10.1242/jcs.254730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 03/15/2021] [Indexed: 01/24/2023] Open
Abstract
Intercellular bridges are essential for fertility in many organisms. The developing fruit fly egg has become the premier model system to study intercellular bridges. During oogenesis, the oocyte is connected to supporting nurse cells by relatively large intercellular bridges, or ring canals. Once formed, the ring canals undergo a 20-fold increase in diameter to support the movement of materials from the nurse cells to the oocyte. Here, we demonstrate a novel role for the conserved SH2/SH3 adaptor protein Dreadlocks (Dock) in regulating ring canal size and structural stability in the germline. Dock localizes at germline ring canals throughout oogenesis. Loss of Dock leads to a significant reduction in ring canal diameter, and overexpression of Dock causes dramatic defects in ring canal structure and nurse cell multinucleation. The SH2 domain of Dock is required for ring canal localization downstream of Src64 (also known as Src64B), and the function of one or more of the SH3 domains is necessary for the strong overexpression phenotype. Genetic interaction and localization studies suggest that Dock promotes WASp-mediated Arp2/3 activation in order to determine ring canal size and regulate growth. This article has an associated First Person interview with the first author of the paper. Summary:Drosophila Dock likely functions downstream of WASp and the Arp2/3 complex to regulate the size and stability of the germline ring canals in the developing egg chamber.
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Affiliation(s)
- Kara Stark
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
| | - Olivia Crowe
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
| | - Lindsay Lewellyn
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
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Kong D, Lu JY, Li X, Zhao S, Xu W, Fang J, Wang X, Ma X. Misshapen Disruption Cooperates with RasV12 to Drive Tumorigenesis. Cells 2021; 10:cells10040894. [PMID: 33919765 PMCID: PMC8070713 DOI: 10.3390/cells10040894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 02/07/2023] Open
Abstract
Although RAS family genes play essential roles in tumorigenesis, effective treatments targeting RAS-related tumors are lacking, partly because of an incomplete understanding of the complex signaling crosstalk within RAS-related tumors. Here, we performed a large-scale genetic screen in Drosophila eye imaginal discs and identified Misshapen (Msn) as a tumor suppressor that synergizes with oncogenic Ras (RasV12) to induce c-Jun N-terminal kinase (JNK) activation and Hippo inactivation, then subsequently leads to tumor overgrowth and invasion. Moreover, ectopic Msn expression activates Hippo signaling pathway and suppresses Hippo signaling disruption-induced overgrowth. Importantly, we further found that Msn acts downstream of protocadherin Fat (Ft) to regulate Hippo signaling. Finally, we identified msn as a Yki/Sd target gene that regulates Hippo pathway in a negative feedback manner. Together, our findings identified Msn as a tumor suppressor and provide a novel insight into RAS-related tumorigenesis that may be relevant to human cancer biology.
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Affiliation(s)
- Du Kong
- School of Medicine, Zhejiang University, Hangzhou 310058, China;
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, China; (S.Z.); (J.F.)
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310024, China;
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou 310024, China
| | - Jin-Yu Lu
- Baylor College of Medicine, Hematology & Oncology, Houston, TX 77054, USA;
| | - Xiaoqin Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China;
- Beijing Key Laboratory of Biodiversity and Organic Farming, Beijing 100193, China
| | - Sihua Zhao
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, China; (S.Z.); (J.F.)
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310024, China;
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou 310024, China
| | - Wenyan Xu
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310024, China;
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou 310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, China
| | - Jinan Fang
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, China; (S.Z.); (J.F.)
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310024, China;
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou 310024, China
| | - Xing Wang
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China;
- Beijing Key Laboratory of Biodiversity and Organic Farming, Beijing 100193, China
- Correspondence: (X.W.); (X.M.)
| | - Xianjue Ma
- School of Medicine, Zhejiang University, Hangzhou 310058, China;
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, China; (S.Z.); (J.F.)
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310024, China;
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou 310024, China
- Correspondence: (X.W.); (X.M.)
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Gerdes JA, Mannix KM, Hudson AM, Cooley L. HtsRC-Mediated Accumulation of F-Actin Regulates Ring Canal Size During Drosophila melanogaster Oogenesis. Genetics 2020; 216:717-734. [PMID: 32883702 PMCID: PMC7648574 DOI: 10.1534/genetics.120.303629] [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: 04/23/2020] [Accepted: 08/30/2020] [Indexed: 12/21/2022] Open
Abstract
Ring canals in the female germline of Drosophila melanogaster are supported by a robust filamentous actin (F-actin) cytoskeleton, setting them apart from ring canals in other species and tissues. Previous work has identified components required for the expansion of the ring canal actin cytoskeleton, but has not identified the proteins responsible for F-actin recruitment or accumulation. Using a combination of CRISPR-Cas9 mediated mutagenesis and UAS-Gal4 overexpression, we show that HtsRC-a component specific to female germline ring canals-is both necessary and sufficient to drive F-actin accumulation. Absence of HtsRC in the germline resulted in ring canals lacking inner rim F-actin, while overexpression of HtsRC led to larger ring canals. HtsRC functions in combination with Filamin to recruit F-actin to ectopic actin structures in somatic follicle cells. Finally, we present findings that indicate that HtsRC expression and robust female germline ring canal expansion are important for high fecundity in fruit flies but dispensable for their fertility-a result that is consistent with our understanding of HtsRC as a newly evolved gene specific to female germline ring canals.
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Affiliation(s)
- Julianne A Gerdes
- Department of Genetics, Yale University School of Medicine, New Haven, 06520 Connecticut
| | - Katelynn M Mannix
- Department of Genetics, Yale University School of Medicine, New Haven, 06520 Connecticut
| | - Andrew M Hudson
- Department of Genetics, Yale University School of Medicine, New Haven, 06520 Connecticut
| | - Lynn Cooley
- Department of Genetics, Yale University School of Medicine, New Haven, 06520 Connecticut
- Department of Cell Biology, Yale University School of Medicine, New Haven, 06520 Connecticut
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511 Connecticut
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The Arp2/3 complex and the formin, Diaphanous, are both required to regulate the size of germline ring canals in the developing egg chamber. Dev Biol 2020; 461:75-85. [PMID: 31945342 DOI: 10.1016/j.ydbio.2020.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 01/10/2020] [Accepted: 01/10/2020] [Indexed: 01/30/2023]
Abstract
Intercellular bridges are an essential structural feature found in both germline and somatic cells throughout the animal kingdom. Because of their large size, the germline intercellular bridges, or ring canals, in the developing fruit fly egg chamber are an excellent model to study the formation, stabilization, and growth of these structures. Within the egg chamber, the germline ring canals connect 15 supporting nurse cells to the developing oocyte, facilitating the transfer of materials required for successful oogenesis. The ring canals are derived from a stalled actomyosin contractile ring; once formed, additional actin and actin-binding proteins are recruited to the ring to support the 20-fold growth that accompanies oogenesis. These behaviors provide a unique model system to study the actin regulators that control incomplete cytokinesis, intercellular bridge formation, and growth. By temporally controlling their expression in the germline, we have demonstrated that the Arp2/3 complex and the formin, Diaphanous (Dia), coordinately regulate ring canal size and growth throughout oogenesis. Dia is required for successful incomplete cytokinesis and the initial stabilization of the germline ring canals. Once ring canals have formed, the Arp2/3 complex and Dia cooperate to determine ring canal size and maintain stability. Our data suggest that nurse cells must maintain a precise balance between the activity of these two nucleators during oogenesis.
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Mannix KM, Starble RM, Kaufman RS, Cooley L. Proximity labeling reveals novel interactomes in live Drosophila tissue. Development 2019; 146:dev.176644. [PMID: 31208963 DOI: 10.1242/dev.176644] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 05/23/2019] [Indexed: 12/19/2022]
Abstract
Gametogenesis is dependent on intercellular communication facilitated by stable intercellular bridges connecting developing germ cells. During Drosophila oogenesis, intercellular bridges (referred to as ring canals; RCs) have a dynamic actin cytoskeleton that drives their expansion to a diameter of 10 μm. Although multiple proteins have been identified as components of RCs, we lack a basic understanding of how RC proteins interact together to form and regulate the RC cytoskeleton. Thus, here, we optimized a procedure for proximity-dependent biotinylation in live tissue using the APEX enzyme to interrogate the RC interactome. APEX was fused to four different RC components (RC-APEX baits) and 55 unique high-confidence prey were identified. The RC-APEX baits produced almost entirely distinct interactomes that included both known RC proteins and uncharacterized proteins. A proximity ligation assay was used to validate close-proximity interactions between the RC-APEX baits and their respective prey. Furthermore, an RNA interference screen revealed functional roles for several high-confidence prey genes in RC biology. These findings highlight the utility of enzyme-catalyzed proximity labeling for protein interactome analysis in live tissue and expand our understanding of RC biology.
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Affiliation(s)
- Katelynn M Mannix
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Rebecca M Starble
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Ronit S Kaufman
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Lynn Cooley
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA .,Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA.,Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA
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