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Chao CF, Pesch YY, Yu H, Wang C, Aristizabal MJ, Huan T, Tanentzapf G, Rideout E. An important role for triglyceride in regulating spermatogenesis. eLife 2024; 12:RP87523. [PMID: 38805376 PMCID: PMC11132686 DOI: 10.7554/elife.87523] [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: 05/30/2024] Open
Abstract
Drosophila is a powerful model to study how lipids affect spermatogenesis. Yet, the contribution of neutral lipids, a major lipid group which resides in organelles called lipid droplets (LD), to sperm development is largely unknown. Emerging evidence suggests LD are present in the testis and that loss of neutral lipid- and LD-associated genes causes subfertility; however, key regulators of testis neutral lipids and LD remain unclear. Here, we show LD are present in early-stage somatic and germline cells within the Drosophila testis. We identified a role for triglyceride lipase brummer (bmm) in regulating testis LD, and found that whole-body loss of bmm leads to defects in sperm development. Importantly, these represent cell-autonomous roles for bmm in regulating testis LD and spermatogenesis. Because lipidomic analysis of bmm mutants revealed excess triglyceride accumulation, and spermatogenic defects in bmm mutants were rescued by genetically blocking triglyceride synthesis, our data suggest that bmm-mediated regulation of triglyceride influences sperm development. This identifies triglyceride as an important neutral lipid that contributes to Drosophila sperm development, and reveals a key role for bmm in regulating testis triglyceride levels during spermatogenesis.
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Affiliation(s)
- Charlotte F Chao
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Yanina-Yasmin Pesch
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Huaxu Yu
- Department of Chemistry, The University of British ColumbiaVancouverCanada
| | - Chenjingyi Wang
- Department of Chemistry, The University of British ColumbiaVancouverCanada
| | | | - Tao Huan
- Department of Chemistry, The University of British ColumbiaVancouverCanada
| | - Guy Tanentzapf
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Elizabeth Rideout
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
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2
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Pfaltzgraff NG, Liu B, de Rooij DG, Page DC, Mikedis MM. Destabilization of mRNAs enhances competence to initiate meiosis in mouse spermatogenic cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.20.557439. [PMID: 37781613 PMCID: PMC10541148 DOI: 10.1101/2023.09.20.557439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
The specialized cell cycle of meiosis transforms diploid germ cells into haploid gametes. In mammals, diploid spermatogenic cells acquire the competence to initiate meiosis in response to retinoic acid. Previous mouse studies revealed that MEIOC interacts with RNA-binding proteins YTHDC2 and RBM46 to repress mitotic genes and promote robust meiotic gene expression in spermatogenic cells that have initiated meiosis. Here, we used the enhanced resolution of scRNA-seq, and bulk RNA-seq of developmentally synchronized spermatogenesis, to define how MEIOC molecularly supports early meiosis in spermatogenic cells. We demonstrate that MEIOC mediates transcriptomic changes before meiotic initiation, earlier than previously appreciated. MEIOC, acting with YTHDC2 and RBM46, destabilizes its mRNA targets, including transcriptional repressors E2f6 and Mga , in mitotic spermatogonia. MEIOC thereby derepresses E2F6- and MGA-repressed genes, including Meiosin and other meiosis-associated genes. This confers on spermatogenic cells the molecular competence to, in response to retinoic acid, fully activate transcriptional regulator STRA8-MEIOSIN, required for the meiotic G1/S phase transition and meiotic gene expression. We conclude that in mice, mRNA decay mediated by MEIOC-YTHDC2-RBM46 enhances the competence of spermatogenic cells to initiate meiosis. SUMMARY STATEMENT RNA-binding complex MEIOC-YTHDC2-RBM46 destabilizes its mRNA targets, including transcriptional repressors. This activity facilitates the retinoic acid-dependent activation of Meiosin gene expression and transition into meiosis.
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3
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Wenzel M, Aquadro CF. Wolbachia infection at least partially rescues the fertility and ovary defects of several new Drosophila melanogaster bag of marbles protein-coding mutants. PLoS Genet 2023; 19:e1011009. [PMID: 37871129 PMCID: PMC10621935 DOI: 10.1371/journal.pgen.1011009] [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: 03/22/2023] [Revised: 11/02/2023] [Accepted: 10/06/2023] [Indexed: 10/25/2023] Open
Abstract
The D. melanogaster protein coding gene bag of marbles (bam) plays a key role in early male and female reproduction by forming complexes with partner proteins to promote differentiation in gametogenesis. Like another germline gene, Sex lethal, bam genetically interacts with the endosymbiont Wolbachia, as Wolbachia rescues the reduced fertility of a bam hypomorphic mutant. Here, we explored the specificity of the bam-Wolbachia interaction by generating 22 new bam mutants, with ten mutants displaying fertility defects. Nine of these mutants trend towards rescue by the wMel Wolbachia variant, with eight statistically significant at the fertility and/or cytological level. In some cases, fertility was increased a striking 20-fold. There is no specificity between the rescue and the known binding regions of bam, suggesting wMel does not interact with one singular bam partner to rescue the reproductive phenotype. We further tested if wMel interacts with bam in a non-specific way, by increasing bam transcript levels or acting upstream in germline stem cells. A fertility assessment of a bam RNAi knockdown mutant reveals that wMel rescue is specific to functionally mutant bam alleles and we find no obvious evidence of wMel interaction with germline stem cells in bam mutants.
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Affiliation(s)
- Miwa Wenzel
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Charles F. Aquadro
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
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4
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Wenzel M, Aquadro CF. Wolbachia infection at least partially rescues the fertility and ovary defects of several new Drosophila melanogaster bag of marbles protein-coding mutants. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.20.532813. [PMID: 37645949 PMCID: PMC10461928 DOI: 10.1101/2023.03.20.532813] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
The D. melanogaster protein coding gene bag of marbles ( bam ) plays a key role in early male and female reproduction by forming complexes with partner proteins to promote differentiation in gametogenesis. Like another germline gene, Sex lethal , bam genetically interacts with the endosymbiont Wolbachia , as Wolbachia rescues the reduced fertility of a bam hypomorphic mutant. Here, we explored the specificity of the bam-Wolbachia interaction by generating 22 new bam mutants, with ten mutants displaying fertility defects. Nine of these mutants trend towards rescue by the w Mel Wolbachia variant, with eight statistically significant at the fertility and/or cytological level. In some cases, fertility was increased a striking 20-fold. There is no specificity between the rescue and the known binding regions of bam , suggesting w Mel does not interact with one singular bam partner to rescue the reproductive phenotype. We further tested if w Mel interacts with bam in a non-specific way, by increasing bam transcript levels or acting upstream in germline stem cells. A fertility assessment of a bam RNAi knockdown mutant reveals that w Mel rescue is specific to functionally mutant bam alleles and we find no obvious evidence of w Mel interaction with germline stem cells in bam mutants. Author Summary Reproduction in the Drosophila melanogaster fruit fly is dependent on the bag of marbles ( bam ) gene, which acts early in the process of generating eggs and sperm. Mutations to this gene negatively impact the fertility of the fly, causing it to be sterile or have fewer progeny. Interestingly, we find that the bacteria Wolbachia , which resides within reproductive cells across a wide range of insects, partially restores the fertility and ovary phenotype of several bam mutants of which the resultant Bam protein is altered from wildtype. The protein function of Bam is further suggested to be important by the lack of rescue for a fly that has a fertility defect due to low expression of a non-mutated bam gene. Previous work makes similar conclusions about Wolbachia with another reproductive gene, Sex lethal ( Sxl ), highlighting the potential for rescue of fertility mutants to occur in a similar way across different genes. An understanding of the ways in which Wolbachia can affect host reproduction provides us with context with which to frame Wolbachia 's impact on host genes, such as bam and Sxl, and consider the evolutionary implications of Wolbachia 's infection in D. melanogaster fruit flies.
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5
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Xing Y, Larson K, Li J, Li WX. Canonical and non-canonical functions of STAT in germline stem cell maintenance. Dev Dyn 2023; 252:728-741. [PMID: 36866634 PMCID: PMC10238624 DOI: 10.1002/dvdy.576] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 02/01/2023] [Accepted: 02/09/2023] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND Maintenance of the Drosophila male germline stem cells (GSCs) requires activation of the Janus kinase/signal transducer and activators of transcription (JAK/STAT) pathway by niche signals. The precise role of JAK/STAT signaling in GSC maintenance, however, remains incompletely understood. RESULTS Here, we show that, GSC maintenance requires both canonical and non-canonical JAK/STAT signaling, in which unphosphorylated STAT (uSTAT) maintains heterochromatin stability by binding to heterochromatin protein 1 (HP1). We found that GSC-specific overexpressing STAT, or even the transcriptionally inactive mutant STAT, increases GSC number and partially rescues the GSC-loss mutant phenotype due to reduced JAK activity. Furthermore, we found that both HP1 and STAT are transcriptional targets of the canonical JAK/STAT pathway in GSCs, and that GSCs exhibit higher heterochromatin content. CONCLUSIONS These results suggest that persistent JAK/STAT activation by niche signals leads to the accumulation of HP1 and uSTAT in GSCs, which promote heterochromatin formation important for maintaining GSC identity. Thus, the maintenance of Drosophila GSCs requires both canonical and non-canonical STAT functions within GSCs for heterochromatin regulation.
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Affiliation(s)
- Yalan Xing
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642
| | - Kimberly Larson
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642
| | - Jinghong Li
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093
| | - Willis X. Li
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642
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6
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Wenzel M, Aquadro CF. Wolbachia genetically interacts with the bag of marbles germline stem cell gene in male D. melanogaster. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000845. [PMID: 37416893 PMCID: PMC10321140 DOI: 10.17912/micropub.biology.000845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 05/20/2023] [Accepted: 05/23/2023] [Indexed: 07/08/2023]
Abstract
The bacterial endosymbiont Wolbachia manipulates reproduction of its arthropod hosts to promote its own maternal vertical transmission. In female D. melanogaster , Wolbachia has been shown to genetically interact with three key reproductive genes ( bag of marbles ( bam ) , Sex-lethal, and mei-P26) , as it rescues the reduced female fertility or fecundity phenotype seen in partial loss-of-function mutants of these genes . Here, we show that Wolbachia also partially rescues male fertility in D. melanogaster carrying a new, largely sterile bam allele when in a bam null genetic background. This finding shows that the molecular mechanism of Wolbachia 's influence on its hosts' reproduction involves interaction with genes in males as well as females, at least in D. melanogaster .
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Affiliation(s)
- Miwa Wenzel
- Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States
| | - Charles F. Aquadro
- Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States
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7
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Romanov SE, Shloma VV, Koryakov DE, Belyakin SN, Laktionov PP. Insulator Protein CP190 Regulates Expression оf Spermatocyte Differentiation Genes in Drosophila melanogaster Male Germline. Mol Biol 2022. [DOI: 10.1134/s0026893323010120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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8
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Peart NJ, Johnson TA, Lee S, Sears MJ, Yang F, Quesnel-Vallières M, Feng H, Recinos Y, Barash Y, Zhang C, Hermann BP, Wang PJ, Geyer CB, Carstens RP. The germ cell-specific RNA binding protein RBM46 is essential for spermatogonial differentiation in mice. PLoS Genet 2022; 18:e1010416. [PMID: 36129965 PMCID: PMC9529142 DOI: 10.1371/journal.pgen.1010416] [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: 05/16/2022] [Revised: 10/03/2022] [Accepted: 09/07/2022] [Indexed: 11/18/2022] Open
Abstract
Control over gene expression is exerted, in multiple stages of spermatogenesis, at the post-transcriptional level by RNA binding proteins (RBPs). We identify here an essential role in mammalian spermatogenesis and male fertility for 'RNA binding protein 46' (RBM46). A highly evolutionarily conserved gene, Rbm46 is also essential for fertility in both flies and fish. We found Rbm46 expression was restricted to the mouse germline, detectable in males in the cytoplasm of premeiotic spermatogonia and meiotic spermatocytes. To define its requirement for spermatogenesis, we generated Rbm46 knockout (KO, Rbm46-/-) mice; although male Rbm46-/- mice were viable and appeared grossly normal, they were infertile. Testes from adult Rbm46-/- mice were small, with seminiferous tubules containing only Sertoli cells and few undifferentiated spermatogonia. Using genome-wide unbiased high throughput assays RNA-seq and 'enhanced crosslinking immunoprecipitation' coupled with RNA-seq (eCLIP-seq), we discovered RBM46 could bind, via a U-rich conserved consensus sequence, to a cohort of mRNAs encoding proteins required for completion of differentiation and subsequent meiotic initiation. In summary, our studies support an essential role for RBM46 in regulating target mRNAs during spermatogonia differentiation prior to the commitment to meiosis in mice.
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Affiliation(s)
- Natoya J. Peart
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Taylor A. Johnson
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Sungkyoung Lee
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Matthew J. Sears
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Fang Yang
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, United States of America
| | - Mathieu Quesnel-Vallières
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Huijuan Feng
- Department of Systems Biology and Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, United States of America
| | - Yocelyn Recinos
- Department of Systems Biology and Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, United States of America
| | - Yoseph Barash
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Chaolin Zhang
- Department of Systems Biology and Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, United States of America
| | - Brian P. Hermann
- Department of Biology, University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - P. Jeremy Wang
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, United States of America
| | - Christopher B. Geyer
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- East Carolina Diabetes and Obesity Institute at East Carolina University, Greenville, North Carolina, United States of America
| | - Russ P. Carstens
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, United States of America
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9
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Qian B, Li Y, Yan R, Han S, Bu Z, Gong J, Zheng B, Yuan Z, Ren S, He Q, Zhang J, Xu C, Wang R, Sun Z, Lin M, Zhou J, Ye L. RNA binding protein RBM46 regulates mitotic-to-meiotic transition in spermatogenesis. SCIENCE ADVANCES 2022; 8:eabq2945. [PMID: 36001654 PMCID: PMC9401620 DOI: 10.1126/sciadv.abq2945] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
Meiosis entry during spermatogenesis requires reprogramming from mitotic to meiotic gene expression profiles. Transcriptional regulation has been extensively studied in meiosis entry, but gain of function for master transcription factors is insufficient to down-regulate mitotic genes. RNA helicase YTHDC2 and its partner MEIOC emerge as essential posttranscriptional regulators of meiotic entry. However, it is unclear what governs the RNA binding specificity of YTHDC2/MEIOC. Here, we identified RNA binding protein RBM46 as a component of the YTHDC2/MEIOC complex. Testis-specific Rbm46 knockout in mice causes infertility with defective mitotic-to-meiotic transition, phenocopying global Ythdc2 or Meioc knockout. RBM46 binds to 3' UTR of mitotic transcripts within 100 nucleotides from YTHDC2 U-rich motifs and targets these transcripts for degradation. Dysregulated RBM46 expression is associated with human male fertility disorders. These findings establish the RBM46/YTHDC2/MEIOC complex as the major posttranscriptional regulator responsible for down-regulating mitotic transcripts during meiosis entry in mammalian spermatogenesis, with implications for understanding meiosis-related fertility disorders.
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Affiliation(s)
- Baomei Qian
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Yang Li
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Ruoyu Yan
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Shenglin Han
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Zhiwen Bu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Jie Gong
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Bangjin Zheng
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Zihan Yuan
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Sen Ren
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Qing He
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Jinwen Zhang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Chen Xu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Ruilin Wang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Zheng Sun
- Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mingyan Lin
- Department of Neurobiology, School of Basic Medical Science, Nanjing Medical University, Nanjing 211166, People’s Republic of China
| | - Jian Zhou
- Department of Pediatric Laboratory, The Affiliated Wuxi Children’s Hospital of Nanjing Medical University, Wuxi, China
| | - Lan Ye
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
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10
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Antel M, Raj R, Masoud MYG, Pan Z, Li S, Mellone BG, Inaba M. Interchromosomal interaction of homologous Stat92E alleles regulates transcriptional switch during stem-cell differentiation. Nat Commun 2022; 13:3981. [PMID: 35810185 PMCID: PMC9271046 DOI: 10.1038/s41467-022-31737-y] [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: 12/11/2021] [Accepted: 06/30/2022] [Indexed: 01/24/2023] Open
Abstract
Pairing of homologous chromosomes in somatic cells provides the opportunity of interchromosomal interaction between homologous gene regions. In the Drosophila male germline, the Stat92E gene is highly expressed in a germline stem cell (GSC) and gradually downregulated during the differentiation. Here we show that the pairing of Stat92E is always tight in GSCs and immediately loosened in differentiating daughter cells, gonialblasts (GBs). Disturbance of Stat92E pairing by relocation of one locus to another chromosome or by knockdown of global pairing/anti-pairing factors both result in a failure of Stat92E downregulation, suggesting that the pairing is required for the decline in transcription. Furthermore, the Stat92E enhancer, but not its transcription, is required for the change in pairing state, indicating that pairing is not a consequence of transcriptional changes. Finally, we show that the change in Stat92E pairing is dependent on asymmetric histone inheritance during the asymmetric division of GSCs. Taken together, we propose that the changes in Stat92E pairing status is an intrinsically programmed mechanism for enabling prompt cell fate switch during the differentiation of stem cells. Asymmetric inheritance of organelles, proteins and RNAs occurs during stem cell division. Here the authors show the strength of pairing of homologous Stat92E loci, a stem cell-specific gene, changes immediately after the asymmetric division due to asymmetric inheritance of new histones to one of the daughter cells and is important for turning off gene expression in this cell as it differentiates.
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Affiliation(s)
- Matthew Antel
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - Romir Raj
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - Madona Y G Masoud
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - Ziwei Pan
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA.,Department of Genetics and Genomic Sciences, University of Connecticut Health Center, Farmington, CT, USA
| | - Sheng Li
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA.,Department of Genetics and Genomic Sciences, University of Connecticut Health Center, Farmington, CT, USA
| | - Barbara G Mellone
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA.,Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
| | - Mayu Inaba
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA.
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11
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Bubnell JE, Ulbing CKS, Fernandez Begne P, Aquadro CF. Functional Divergence of the bag-of-marbles Gene in the Drosophila melanogaster Species Group. Mol Biol Evol 2022; 39:6609986. [PMID: 35714266 PMCID: PMC9250105 DOI: 10.1093/molbev/msac137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
In Drosophila melanogaster, a key germline stem cell (GSC) differentiation factor, bag of marbles (bam) shows rapid bursts of amino acid fixations between sibling species D. melanogaster and Drosophila simulans, but not in the outgroup species Drosophila ananassae. Here, we test the null hypothesis that bam's differentiation function is conserved between D. melanogaster and four additional Drosophila species in the melanogaster species group spanning approximately 30 million years of divergence. Surprisingly, we demonstrate that bam is not necessary for oogenesis or spermatogenesis in Drosophila teissieri nor is bam necessary for spermatogenesis in D. ananassae. Remarkably bam function may change on a relatively short time scale. We further report tests of neutral sequence evolution at bam in additional species of Drosophila and find a positive, but not perfect, correlation between evidence for positive selection at bam and its essential role in GSC regulation and fertility for both males and females. Further characterization of bam function in more divergent lineages will be necessary to distinguish between bam's critical gametogenesis role being newly derived in D. melanogaster, D. simulans, Drosophila yakuba, and D. ananassae females or it being basal to the genus and subsequently lost in numerous lineages.
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Affiliation(s)
| | - Cynthia K S Ulbing
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
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12
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Autophagy is required for spermatogonial differentiation in the Drosophila testis. Biol Futur 2022; 73:187-204. [DOI: 10.1007/s42977-022-00122-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 05/13/2022] [Indexed: 10/18/2022]
Abstract
AbstractAutophagy is a conserved, lysosome-dependent catabolic process of eukaryotic cells which is involved in cellular differentiation. Here, we studied its specific role in the differentiation of spermatogonial cells in the Drosophila testis. In the apical part of the Drosophila testis, there is a niche of germline stem cells (GSCs), which are connected to hub cells. Hub cells emit a ligand for bone morhphogenetic protein (BMP)-mediated signalling that represses Bam (bag of marbles) expression in GSCs to maintain them in an undifferentiated state. GSCs divide asymmetrically, and one of the daughter cells differentiates into a gonialblast, which eventually generates a cluster of spermatogonia (SG) by mitoses. Bam is active in SG, and defects in Bam function arrest these cells at mitosis. We show that BMP signalling represses autophagy in GSCs, but upregulates the process in SG. Inhibiting autophagy in SG results in an overproliferating phenotype similar to that caused by bam mutations. Furthermore, Bam deficiency leads to a failure in downstream mechanisms of the autophagic breakdown. These results suggest that the BMP-Bam signalling axis regulates developmental autophagy in the Drosophila testis, and that acidic breakdown of cellular materials is required for spermatogonial differentiation.
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13
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Salerno-Kochan A, Horn A, Ghosh P, Nithin C, Kościelniak A, Meindl A, Strauss D, Krutyhołowa R, Rossbach O, Bujnicki JM, Gaik M, Medenbach J, Glatt S. Molecular insights into RNA recognition and gene regulation by the TRIM-NHL protein Mei-P26. Life Sci Alliance 2022; 5:5/8/e202201418. [PMID: 35512835 PMCID: PMC9070667 DOI: 10.26508/lsa.202201418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 02/06/2023] Open
Abstract
The TRIM-NHL protein Meiotic P26 (Mei-P26) acts as a regulator of cell fate in Drosophila Its activity is critical for ovarian germline stem cell maintenance, differentiation of oocytes, and spermatogenesis. Mei-P26 functions as a post-transcriptional regulator of gene expression; however, the molecular details of how its NHL domain selectively recognizes and regulates its mRNA targets have remained elusive. Here, we present the crystal structure of the Mei-P26 NHL domain at 1.6 Å resolution and identify key amino acids that confer substrate specificity and distinguish Mei-P26 from closely related TRIM-NHL proteins. Furthermore, we identify mRNA targets of Mei-P26 in cultured Drosophila cells and show that Mei-P26 can act as either a repressor or activator of gene expression on different RNA targets. Our work reveals the molecular basis of RNA recognition by Mei-P26 and the fundamental functional differences between otherwise very similar TRIM-NHL proteins.
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Affiliation(s)
- Anna Salerno-Kochan
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland.,Postgraduate School of Molecular Medicine, Warsaw, Poland
| | - Andreas Horn
- Biochemistry I, University of Regensburg, Regensburg, Germany
| | - Pritha Ghosh
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Chandran Nithin
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Anna Kościelniak
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Andreas Meindl
- Biochemistry I, University of Regensburg, Regensburg, Germany
| | - Daniela Strauss
- Biochemistry I, University of Regensburg, Regensburg, Germany
| | | | - Oliver Rossbach
- Institute of Biochemistry, University of Giessen, Giessen, Germany
| | - Janusz M Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Warsaw, Poland.,Bioinformatics Laboratory, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
| | - Monika Gaik
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Jan Medenbach
- Biochemistry I, University of Regensburg, Regensburg, Germany
| | - Sebastian Glatt
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
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14
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Chen TA, Lin KY, Yang SM, Tseng CY, Wang YT, Lin CH, Luo L, Cai Y, Hsu HJ. Canonical Wnt Signaling Promotes Formation of Somatic Permeability Barrier for Proper Germ Cell Differentiation. Front Cell Dev Biol 2022; 10:877047. [PMID: 35517512 PMCID: PMC9062081 DOI: 10.3389/fcell.2022.877047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/16/2022] [Indexed: 11/22/2022] Open
Abstract
Morphogen-mediated signaling is critical for proper organ development and stem cell function, and well-characterized mechanisms spatiotemporally limit the expression of ligands, receptors, and ligand-binding cell-surface glypicans. Here, we show that in the developing Drosophila ovary, canonical Wnt signaling promotes the formation of somatic escort cells (ECs) and their protrusions, which establish a physical permeability barrier to define morphogen territories for proper germ cell differentiation. The protrusions shield germ cells from Dpp and Wingless morphogens produced by the germline stem cell (GSC) niche and normally only received by GSCs. Genetic disruption of EC protrusions allows GSC progeny to also receive Dpp and Wingless, which subsequently disrupt germ cell differentiation. Our results reveal a role for canonical Wnt signaling in specifying the ovarian somatic cells necessary for germ cell differentiation. Additionally, we demonstrate the morphogen-limiting function of this physical permeability barrier, which may be a common mechanism in other organs across species.
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Affiliation(s)
- Ting-An Chen
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Kun-Yang Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Shun-Min Yang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
- Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Chen-Yuan Tseng
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Yu-Ting Wang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Chi-Hung Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Lichao Luo
- Temasek Life Science Laboratory, National University of Singapore, Singapore, Singapore
| | - Yu Cai
- Temasek Life Science Laboratory, National University of Singapore, Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Hwei-Jan Hsu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
- *Correspondence: Hwei-Jan Hsu,
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15
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Ilyin AA, Kononkova AD, Golova AV, Shloma VV, Olenkina O, Nenasheva V, Abramov Y, Kotov AA, Maksimov D, Laktionov P, Pindyurin A, Galitsyna A, Ulianov S, Khrameeva E, Gelfand M, Belyakin S, Razin S, Shevelyov Y. OUP accepted manuscript. Nucleic Acids Res 2022; 50:3203-3225. [PMID: 35166842 PMCID: PMC8989536 DOI: 10.1093/nar/gkac109] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/19/2022] [Accepted: 02/03/2022] [Indexed: 11/14/2022] Open
Abstract
Eukaryotic chromosomes are spatially segregated into topologically associating domains (TADs). Some TADs are attached to the nuclear lamina (NL) through lamina-associated domains (LADs). Here, we identified LADs and TADs at two stages of Drosophila spermatogenesis – in bamΔ86 mutant testes which is the commonly used model of spermatogonia (SpG) and in larval testes mainly filled with spermatocytes (SpCs). We found that initiation of SpC-specific transcription correlates with promoters’ detachment from the NL and with local spatial insulation of adjacent regions. However, this insulation does not result in the partitioning of inactive TADs into sub-TADs. We also revealed an increased contact frequency between SpC-specific genes in SpCs implying their de novo gathering into transcription factories. In addition, we uncovered the specific X chromosome organization in the male germline. In SpG and SpCs, a single X chromosome is stronger associated with the NL than autosomes. Nevertheless, active chromatin regions in the X chromosome interact with each other more frequently than in autosomes. Moreover, despite the absence of dosage compensation complex in the male germline, randomly inserted SpG-specific reporter is expressed higher in the X chromosome than in autosomes, thus evidencing that non-canonical dosage compensation operates in SpG.
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Affiliation(s)
| | | | | | | | | | - Valentina V Nenasheva
- Institute of Molecular Genetics of National Research Centre “Kurchatov Institute”, Moscow 123182, Russia
| | - Yuri A Abramov
- Institute of Molecular Genetics of National Research Centre “Kurchatov Institute”, Moscow 123182, Russia
| | - Alexei A Kotov
- Institute of Molecular Genetics of National Research Centre “Kurchatov Institute”, Moscow 123182, Russia
| | - Daniil A Maksimov
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Petr P Laktionov
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Alexey V Pindyurin
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090, Russia
| | | | - Sergey V Ulianov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow119334, Russia
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow 119992, Russia
| | - Ekaterina E Khrameeva
- Correspondence may also be addressed to Ekaterina Khrameeva. Tel: +7 495 2801481; Fax: +7 495 2801481;
| | - Mikhail S Gelfand
- Skolkovo Institute of Science and Technology, Skolkovo 143026, Russia
- A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow 127051, Russia
| | - Stepan N Belyakin
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Sergey V Razin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow119334, Russia
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow 119992, Russia
| | - Yuri Y Shevelyov
- To whom correspondence should be addressed. Tel: +7 499 1960809; Fax: +7 499 1960221;
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16
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Wu J, Li X, Gao Z, Pang L, Liu X, Huang X, Wang Y, Wang Z. RNA kinase CLP1/Cbc regulates meiosis initiation in spermatogenesis. Hum Mol Genet 2021; 30:1569-1578. [PMID: 33864361 PMCID: PMC8369837 DOI: 10.1093/hmg/ddab107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/08/2021] [Accepted: 04/08/2021] [Indexed: 11/14/2022] Open
Abstract
CLP1, TSEN complex, and VCP are evolutionarily conserved proteins whose mutations are associated with neurodegenerative diseases. In this study, we have found that they are also involved in germline differentiation. To optimize both quantity and quality in gametes production, germ cells expand themselves through limited mitotic cycles prior to meiosis. Stemming from our previous findings on the correlation between mRNA 3'-processing and meiosis entry, here we identify that the RNA kinase Cbc, the Drosophila member of the highly conserved CLP1 family, is a component of the program regulating the transition from mitosis to meiosis. Using genetic manipulations in Drosophila testis, we demonstrate that nuclear Cbc is required to promote meiosis entry. Combining biochemical and genetic methods, we reveal that Cbc physically and/or genetically intersects with Tsen54 and TER94 (VCP ortholog) in this process. The C-terminal half of Tsen54 is both necessary and sufficient for its binding with Cbc. Further, we illustrate the functional conservation between Cbc and mammalian CLP1 in the assays of subcellular localization and Drosophila fertility. As CLP1, TSEN complex, and VCP have also been identified in neurodegenerations of animal models, a mechanism involving these factors seems to be shared in gametogenesis and neurogenesis.
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Affiliation(s)
- Jianbo Wu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
- The University of Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
| | - Xin Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
| | - Zhiyang Gao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
| | - Lin Pang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
- The University of Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
| | - Xian Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
- The University of Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
| | - Xiahe Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
| | - Zhaohui Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
- The University of Chinese Academy of Sciences, BeiChenXiLu#1, Beijing 100101, P.R. China
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17
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Kahney EW, Zion EH, Sohn L, Viets-Layng K, Johnston R, Chen X. Characterization of histone inheritance patterns in the Drosophila female germline. EMBO Rep 2021; 22:e51530. [PMID: 34031963 PMCID: PMC8406404 DOI: 10.15252/embr.202051530] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 04/02/2021] [Accepted: 04/16/2021] [Indexed: 11/30/2022] Open
Abstract
Stem cells have the unique ability to undergo asymmetric division which produces two daughter cells that are genetically identical, but commit to different cell fates. The loss of this balanced asymmetric outcome can lead to many diseases, including cancer and tissue dystrophy. Understanding this tightly regulated process is crucial in developing methods to treat these abnormalities. Here, we report that during a Drosophila female germline stem cell asymmetric division, the two daughter cells differentially inherit histones at key genes related to either maintaining the stem cell state or promoting differentiation, but not at constitutively active or silenced genes. We combine histone labeling with DNA Oligopaints to distinguish old versus new histones and visualize their inheritance patterns at a single‐gene resolution in asymmetrically dividing cells in vivo. This strategy can be applied to other biological systems involving cell fate change during development or tissue homeostasis in multicellular organisms.
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Affiliation(s)
| | - Emily H Zion
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Lydia Sohn
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Kayla Viets-Layng
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Robert Johnston
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
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18
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Zhou H, Whitworth C, Pozmanter C, Neville MC, Van Doren M. Doublesex regulates fruitless expression to promote sexual dimorphism of the gonad stem cell niche. PLoS Genet 2021; 17:e1009468. [PMID: 33788836 PMCID: PMC8041189 DOI: 10.1371/journal.pgen.1009468] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 04/12/2021] [Accepted: 03/04/2021] [Indexed: 11/25/2022] Open
Abstract
Doublesex (Dsx) and Fruitless (Fru) are the two downstream transcription factors that actuate Drosophila sex determination. While Dsx assists Fru to regulate sex-specific behavior, whether Fru collaborates with Dsx in regulating other aspects of sexual dimorphism remains unknown. One important aspect of sexual dimorphism is found in the gonad stem cell (GSC) niches, where male and female GSCs are regulated to create large numbers of sperm and eggs. Here we report that Fru is expressed male-specifically in the GSC niche and plays important roles in the development and maintenance of these cells. Unlike previously-studied aspects of sex-specific Fru expression, which are regulated by Transformer (Tra)-mediated alternative splicing, we show that male-specific expression of fru in the gonad is regulated downstream of dsx, and is independent of tra. fru genetically interacts with dsx to support maintenance of the niche throughout development. Ectopic expression of fru inhibited female niche formation and partially masculinized the ovary. fru is also required autonomously for cyst stem cell maintenance and cyst cell survival. Finally, we identified a conserved Dsx binding site upstream of fru promoter P4 that regulates fru expression in the niche, indicating that fru is likely a direct target for transcriptional regulation by Dsx. These findings demonstrate that fru acts outside the nervous system to influence sexual dimorphism and reveal a new mechanism for regulating sex-specific expression of fru that is regulated at the transcriptional level by Dsx, rather than by alternative splicing by Tra. In animals, the process of sex determination controls the development of sexual dimorphism—the differences in appearance, physiology and behavior observed between males and females of a species. These differences are important for key functions such as sexual reproduction, and also influence other characteristics such as sex-specific disease progression. An important family of transcription factors, the Doublesex, mab-3 Related Transcription factors (DMRTs) control sex-specific development, particularly in the gonads, in most or all animals where they have been studied. Thus, an essential question in biology is how do the DMRTs control sex-specific development? In Drosophila, another set of transcription factors, encoded by the fruitless (fru) gene, controls sex-specific development of the nervous system and is thought to be regulated independently of the Drosophila DMRT Doublesex (Dsx). Here we present two important changes to our thinking about sexual development: 1) fru also acts to control sex-specific development outside the nervous system (in the gonad) and 2) sex-specific fru expression can be regulated by Dsx, in addition to its Dsx-independent regulation, providing a new mechanism for fru regulation that may be broadly utilized.
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Affiliation(s)
- Hong Zhou
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, United States of America
| | - Cale Whitworth
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, United States of America
| | - Caitlin Pozmanter
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, United States of America
| | - Megan C. Neville
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, United Kingdom
| | - Mark Van Doren
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, United States of America
- * E-mail:
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19
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Yang SY. Germline masculinization by Phf7 in D. melanogaster requires its evolutionarily novel C-terminus and the HP1-family protein HP1D3csd. Sci Rep 2021; 11:6308. [PMID: 33737548 PMCID: PMC7973481 DOI: 10.1038/s41598-021-85560-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 02/25/2021] [Indexed: 11/09/2022] Open
Abstract
Germ cells in Drosophila melanogaster need intrinsic factors along with somatic signals to activate proper sexual programs. A key factor for male germline sex determination is PHD finger protein 7 (Phf7), a histone reader expressed in the male germline that can trigger sex reversal in female germ cells and is also important for efficient spermatogenesis. Here we find that the evolutionarily novel C-terminus in Phf7 is necessary to turn on the complete male program in the early germline of D. melanogaster, suggesting that this domain may have been uniquely acquired to regulate sexual differentiation. We further looked for genes regulated by Phf7 related to sex determination in the embryonic germline by transcriptome profiling of FACS-purified embryonic gonads. One of the genes positively-regulated by Phf7 in the embryonic germline was an HP1family member, Heterochromatin Protein 1D3 chromoshadow domain (HP1D3csd). We find that this gene is needed for Phf7 to induce male-like development in the female germline, indicating that HP1D3csd is an important factor acting downstream of Phf7 to regulate germline masculinization.
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Affiliation(s)
- Shu Yuan Yang
- Department and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, 333, Taiwan. .,Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Linkou Chang Gung Memorial Hospital, Taoyuan, 333, Taiwan.
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20
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Nandi A, Chowdhuri DK. Cadmium mediated redox modulation in germline stem cells homeostasis affects reproductive health of Drosophila males. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123737. [PMID: 33254766 DOI: 10.1016/j.jhazmat.2020.123737] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 08/07/2020] [Accepted: 08/14/2020] [Indexed: 06/12/2023]
Abstract
Maintenance of male germline stem cells (GSCs) homeostasis is crucial for successful reproductive life of adults. New insights gained on dysfunction in stem cell maintenance could be the basis of stem cell dependent ailment during adulthood. Cadmium (Cd), a reported male reproductive toxicant, has been explored inadequately for its impact on male GSCs maintenance. The present study, therefore, has been aimed to evaluate the adverse effect of Cd on the homeostasis of GSCs by using Drosophila testis as an in vivo model. Following developmental exposure of environmentally relevant concentrations of Cd (5.0, 10.0 and 20.0 μg/mL) to Drosophila, we showed that a significantly increased level of reactive oxygen species (ROS) at 20.0 μg/mL of Cd resulted in alteration of GSCs number accompanied by inappropriate differentiation leading to reduced sperm number and eventually poor reproductive performance in exposed organism. Rescuing effect was evident by overexpressing sod in the early germ cell stage. The study suggests that an alteration in GSCs homeostasis due to redox imbalance plays a pivotal role in Cd induced failure in male fertility. The study further advocates for the use of Drosophila as an alternative animal model for in vivo evaluation of male GSCs toxicity with minimal ethical concern.
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Affiliation(s)
- Abik Nandi
- Embryotoxicology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31, Mahatma Gandhi Marg, Lucknow 226 001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, Uttar Pradesh, India
| | - Debapratim Kar Chowdhuri
- Embryotoxicology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31, Mahatma Gandhi Marg, Lucknow 226 001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, Uttar Pradesh, India.
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21
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Tudor-domain containing protein 5-like promotes male sexual identity in the Drosophila germline and is repressed in females by Sex lethal. PLoS Genet 2019; 15:e1007617. [PMID: 31329582 PMCID: PMC6645463 DOI: 10.1371/journal.pgen.1007617] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 06/26/2019] [Indexed: 11/19/2022] Open
Abstract
For sexually reproducing organisms, production of male or female gametes depends on specifying the correct sexual identity in the germline. In D. melanogaster, Sex lethal (Sxl) is the key gene that controls sex determination in both the soma and the germline, but how it does so in the germline is unknown, other than that it is different than in the soma. We conducted an RNA expression profiling experiment to identify direct and indirect germline targets of Sxl specifically in the undifferentiated germline. We find that, in these cells, Sxl loss does not lead to a global masculinization observed at the whole-genome level. In contrast, Sxl appears to affect a discrete set of genes required in the male germline, such as Phf7. We also identify Tudor domain containing protein 5-like (Tdrd5l) as a target for Sxl regulation that is important for male germline identity. Tdrd5l is repressed by Sxl in female germ cells, but is highly expressed in male germ cells where it promotes proper male fertility and germline differentiation. Additionally, Tdrd5l localizes to cytoplasmic granules with some characteristics of RNA Processing (P-) Bodies, suggesting that it promotes male identity in the germline by regulating post-transcriptional gene expression.
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22
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Reproduction disrupts stem cell homeostasis in testes of aged male Drosophila via an induced microenvironment. PLoS Genet 2019; 15:e1008062. [PMID: 31295251 PMCID: PMC6622487 DOI: 10.1371/journal.pgen.1008062] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 03/02/2019] [Indexed: 12/13/2022] Open
Abstract
Stem cells rely on instructive cues from their environment. Alterations in microenvironments might contribute to tissue dysfunction and disease pathogenesis. Germline stem cells (GSCs) and cyst stem cells (CySC) in Drosophila testes are normally maintained in the apical area by the testicular hub. In this study, we found that reproduction leads to accumulation of early differentiating daughters of CySCs and GSCs in the testes of aged male flies, due to hyperactivation of Jun-N-terminal kinase (JNK) signaling to maintain self-renewal gene expression in the differentiating cyst cells. JNK activity is normally required to maintain CySCs in the apical niche. A muscle sheath surrounds the Drosophila testis to maintain its long coiled structure. Importantly, reproduction triggers accumulation of the tumor necrosis factor (TNF) Eiger in the testis muscle to activate JNK signaling via the TNF receptor Grindelwald in the cyst cells. Reducing Eiger activity in the testis muscle sheath suppressed reproduction-induced differentiation defects, but had little effect on testis homeostasis of unmated males. Our results reveal that reproduction in males provokes a dramatic shift in the testicular microenvironment, which impairs tissue homeostasis and spermatogenesis in the testes. Proper differentiation of stem cell progeny is necessary for preservation of tissue homeostasis. In Drosophila testes, somatic cyst cells derived from the cyst stem cells (CySCs) control the differentiation of the neighboring germ cells. Disruption of CySC daughter cyst cell differentiation leads to failure in sperm production. Interestingly, we found that reproduction triggers hyperactivation of Jun-N-terminal kinase (JNK) signaling to sustain CySC self-renewal gene expression in differentiating cyst cells, leading to accumulation of immature cyst cell and germ cells at the expense of mature cells in the testes of aged males. Endogenous JNK signaling is also required for CySC maintenance. Moreover, we found that the JNK signaling is hyperactivated via reproduction-induced accumulation of tumor necrosis factor (TNF) in testicular smooth muscle that surrounds the testis to support its long coiled structure. The reproduction-induced phenotypes were only observed in the testes of aged and mated males, but not in testes form young mated males or aged unmated males, indicating that it is a combined effect of reproduction and aging. Our results reveal that reproduction impedes sperm production in aged males, and identify testicular muscle as an inducible signaling center for spermatogenesis in Drosophila.
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23
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Precursor RNA processing 3 is required for male fertility, and germline stem cell self-renewal and differentiation via regulating spliceosome function in Drosophila testes. Sci Rep 2019; 9:9988. [PMID: 31292463 PMCID: PMC6620278 DOI: 10.1038/s41598-019-46419-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 06/28/2019] [Indexed: 11/17/2022] Open
Abstract
The nuclear pre-mRNA spliceosome is a large complex containing five small nuclear ribonucleoprotein particles (snRNPs) and many splicing factors. Messenger RNAs (mRNAs) are generated from pre-mRNAs by the process of RNA splicing, which is conserved in eukaryotes. Precursor RNA processing 3 (Prp3) is a U4/U6-associated snRNP whose function remains largely unknown. In the present study, using genetic manipulation of a Drosophila melanogaster testis model, we demonstrated that Prp3 is essential for male fertility in Drosophila. Prp3 deficiency in germline stem cells (GSCs) and early cyst cells resulted in abnormal structure of testes and maintenance defects of GSCs and cyst stem cells. Knockdown of Prp3 in spermatogonia and early cyst cells mediated tumor formation caused by differentiation defects. Using an in vitro assay, knockdown of Prp3 decreased proliferation and increased cell death, and controlled the spliceosome function via regulating spliceosome subunits expression in Drosophila S2 cells. We also identified two other splicing factors in the Prp complex (Prp19 and Prp8), which mimicked the phenotype of Prp3 in the Drosophila stem cell niche. Our results revealed a significant role of precursor RNA processing factors in male testes, indicating that Prp3, a key spliceosome component in the Prp complex, is essential for male fertility, and germline stem cell self-renewal and differentiation, via regulating the spliceosome function in Drosophila testes.
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24
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Primus S, Pozmanter C, Baxter K, Van Doren M. Tudor-domain containing protein 5-like promotes male sexual identity in the Drosophila germline and is repressed in females by Sex lethal. PLoS Genet 2019. [PMID: 31329582 DOI: 10.1101/388850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023] Open
Abstract
For sexually reproducing organisms, production of male or female gametes depends on specifying the correct sexual identity in the germline. In D. melanogaster, Sex lethal (Sxl) is the key gene that controls sex determination in both the soma and the germline, but how it does so in the germline is unknown, other than that it is different than in the soma. We conducted an RNA expression profiling experiment to identify direct and indirect germline targets of Sxl specifically in the undifferentiated germline. We find that, in these cells, Sxl loss does not lead to a global masculinization observed at the whole-genome level. In contrast, Sxl appears to affect a discrete set of genes required in the male germline, such as Phf7. We also identify Tudor domain containing protein 5-like (Tdrd5l) as a target for Sxl regulation that is important for male germline identity. Tdrd5l is repressed by Sxl in female germ cells, but is highly expressed in male germ cells where it promotes proper male fertility and germline differentiation. Additionally, Tdrd5l localizes to cytoplasmic granules with some characteristics of RNA Processing (P-) Bodies, suggesting that it promotes male identity in the germline by regulating post-transcriptional gene expression.
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Affiliation(s)
- Shekerah Primus
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Caitlin Pozmanter
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Kelly Baxter
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Mark Van Doren
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
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25
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La Marca JE, Diepstraten ST, Hodge AL, Wang H, Hart AH, Richardson HE, Somers WG. Strip and Cka negatively regulate JNK signalling during Drosophila spermatogenesis. Development 2019; 146:dev.174292. [PMID: 31164352 DOI: 10.1242/dev.174292] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 05/24/2019] [Indexed: 12/16/2022]
Abstract
One fundamental property of a stem cell niche is the exchange of molecular signals between its component cells. Niche models, such as the Drosophila melanogaster testis, have been instrumental in identifying and studying the conserved genetic factors that contribute to niche molecular signalling. Here, we identify jam packed (jam), an allele of Striatin interacting protein (Strip), which is a core member of the highly conserved Striatin-interacting phosphatase and kinase (STRIPAK) complex. In the developing Drosophila testis, Strip cell-autonomously regulates the differentiation and morphology of the somatic lineage, and non-cell-autonomously regulates the proliferation and differentiation of the germline lineage. Mechanistically, Strip acts in the somatic lineage with its STRIPAK partner, Connector of kinase to AP-1 (Cka), where they negatively regulate the Jun N-terminal kinase (JNK) signalling pathway. Our study reveals a novel role for Strip/Cka in JNK pathway regulation during spermatogenesis within the developing Drosophila testis.
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Affiliation(s)
- John E La Marca
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia 3086
| | - Sarah T Diepstraten
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia 3086
| | - Amy L Hodge
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia 3086
| | - Hongyan Wang
- Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore 169857.,National University of Singapore Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456.,Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
| | - Adam H Hart
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia 3086
| | - Helena E Richardson
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia 3086
| | - W Gregory Somers
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia 3086
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26
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Camara N, Whitworth C, Dove A, Van Doren M. Doublesex controls specification and maintenance of the gonad stem cell niches in Drosophila. Development 2019; 146:dev.170001. [PMID: 31043421 DOI: 10.1242/dev.170001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 04/23/2019] [Indexed: 11/20/2022]
Abstract
Sex-specific development of the gonads is a key aspect of sexual dimorphism that is regulated by Doublesex/Mab3-related transcription factors (DMRTs) in diverse animal species. We find that in mutants for Drosophila dsx, important components of the male and female gonad stem cell niches (hubs and terminal filaments/cap cells, respectively) still form. Initially, gonads in all dsx mutants (both XX and XY) initiate the male program of development, but later half of these gonads switch to form female stem cell niche structures. One individual can have both male-type and female-type gonad niches; however, male and female niches are usually not observed in the same gonad, indicating that cells make a 'group decision' about which program to follow. We conclude that dsx does not act in an instructive manner to regulate male versus female niche formation, as these structures form in the absence of dsx function. Instead, dsx acts to 'tip the balance' between the male or female programs, which are then executed independently of dsx We show that bric a brac acts downstream of dsx to control the male versus female niche decision. These results indicate that, in both flies and mammals, the sexual fate of the somatic gonad is remarkably plastic and is controlled by a combination of autonomous and non-autonomous cues.
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Affiliation(s)
- Nicole Camara
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Cale Whitworth
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Abigail Dove
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Mark Van Doren
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
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27
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Yu J, Yan Y, Luan X, Qiao C, Liu Y, Zhao D, Xie B, Zheng Q, Wang M, Chen W, Shen C, He Z, Hu X, Huang X, Li H, Shao Q, Chen X, Zheng B, Fang J. Srlp is crucial for the self-renewal and differentiation of germline stem cells via RpL6 signals in Drosophila testes. Cell Death Dis 2019; 10:294. [PMID: 30931935 PMCID: PMC6443671 DOI: 10.1038/s41419-019-1527-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 03/11/2019] [Accepted: 03/14/2019] [Indexed: 12/22/2022]
Abstract
Self-renewal and differentiation in germline stem cells (GSCs) are tightly regulated by the stem cell niche and via multiple approaches. In our previous study, we screened the novel GSC regulatory gene Srlp in Drosophila testes. However, the underlying mechanistic links between Srlp and the stem cell niche remain largely undetermined. Here, using genetic manipulation of the Drosophila model, we systematically analyze the function and mechanism of Srlp in vivo and in vitro. In Drosophila, Srlp is an essential gene that regulates the self-renewal and differentiation of GSCs in the testis. In the in vitro assay, Srlp is found to control the proliferation ability and cell death in S2 cells, which is consistent with the phenotype observed in Drosophila testis. Furthermore, results of the liquid chromatography-tandem mass spectrometry (LC-MS/MS) reveal that RpL6 binds to Srlp. Srlp also regulates the expression of spliceosome and ribosome subunits and controls spliceosome and ribosome function via RpL6 signals. Collectively, our findings uncover the genetic causes and molecular mechanisms underlying the stem cell niche. This study provides new insights for elucidating the pathogenic mechanism of male sterility and the formation of testicular germ cell tumor.
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Affiliation(s)
- Jun Yu
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Yidan Yan
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Xiaojin Luan
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Chen Qiao
- Department of Clinical Pharmacy, the Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Yuanyuan Liu
- Center for Reproduction and Genetics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Jiangsu, 215002, China
| | - Dan Zhao
- Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Center for Reproduction, The Fourth People's Hospital of Zhenjiang, Zhenjiang Jiangsu, 212013, China
| | - Bing Xie
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Qianwen Zheng
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Min Wang
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Wanyin Chen
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Cong Shen
- Center for Reproduction and Genetics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Jiangsu, 215002, China
| | - Zeyu He
- Department of Clinical Medicine, China Medical University, Shenyang Liaoning, 110001, China
| | - Xing Hu
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Xiaoyan Huang
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing Jiangsu, 211166, China
| | - Hong Li
- Center for Reproduction and Genetics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Jiangsu, 215002, China
| | - Qixiang Shao
- Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Department of Immunology and Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, School of Medicine, Jiangsu University, Zhenjiang Jiangsu, 212013, China
| | - Xia Chen
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China. .,Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China.
| | - Bo Zheng
- Center for Reproduction and Genetics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Jiangsu, 215002, China.
| | - Jie Fang
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China.
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28
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Gupta S, Varshney B, Chatterjee S, Ray K. Somatic ERK activation during transit amplification is essential for maintaining the synchrony of germline divisions in Drosophila testis. Open Biol 2019; 8:rsob.180033. [PMID: 30045884 PMCID: PMC6070716 DOI: 10.1098/rsob.180033] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 06/28/2018] [Indexed: 12/23/2022] Open
Abstract
Transit amplification (TA) of progenitor cells maintains tissue homeostasis by balancing proliferation and differentiation. In Drosophila testis, the germline proliferation is tightly regulated by factors present in both the germline and the neighbouring somatic cyst cells (SCCs). Although the exact mechanism is unclear, the epidermal growth factor receptor (EGFR) activation in SCCs has been reported to control spermatogonial divisions within a cyst, through downstream activations of Rac1-dependent pathways. Here, we report that somatic activation of the mitogen-activated protein kinase (Rolled/ERK) downstream of EGFR is required to synchronize the mitotic divisions and regulate the transition to meiosis. The process operates independently of the Bag-of-marble activity in the germline. Also, the integrity of the somatic cyst enclosure is inessential for this purpose. Together, these results suggest that synchronization of germ-cell divisions through somatic activation of distinct ERK-downstream targets independently regulates TA and subsequent differentiation of neighbouring germline cells.
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Affiliation(s)
- Samir Gupta
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Bhavana Varshney
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Shambhabi Chatterjee
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Krishanu Ray
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
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29
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Lenhart KF, Capozzoli B, Warrick GSD, DiNardo S. Diminished Jak/STAT Signaling Causes Early-Onset Aging Defects in Stem Cell Cytokinesis. Curr Biol 2019; 29:256-267.e3. [PMID: 30612906 DOI: 10.1016/j.cub.2018.11.064] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 11/12/2018] [Accepted: 11/28/2018] [Indexed: 01/09/2023]
Abstract
Tissue renewal becomes compromised with age. Although defects in niche and stem cell behavior have been implicated in promoting age-related decline, the causes of early-onset aging defects are unknown. We have identified an early consequence of aging in germline stem cells (GSCs) in the Drosophila testis. Aging disrupts the unique program of GSC cytokinesis, with GSCs failing to abscise from their daughter cells. Abscission failure significantly disrupts both self-renewal and the generation of differentiating germ cells. Extensive live imaging and genetic analyses show that abscission failure is due to inappropriate retention of F-actin at the intercellular bridges between GSC-daughter cells. Furthermore, F-actin is regulated by the Jak/STAT pathway-increasing or decreasing pathway activity can rescue or exacerbate the age-induced abscission defect, respectively. Even subtle decreases to STAT activity are sufficient to precociously age young GSCs and induce abscission failure. Thus, this work has identified the earliest age-related defect in GSCs and has revealed a unique role for an established niche signaling pathway in controlling stem cell cytokinesis and in regulating stem cell behavior with age.
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Affiliation(s)
- Kari F Lenhart
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biology, Drexel University, Philadelphia, PA 19104, USA.
| | - Benjamin Capozzoli
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gwen S D Warrick
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Stephen DiNardo
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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30
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Levings DC, Nakato H. Loss of heparan sulfate in the niche leads to tumor-like germ cell growth in the Drosophila testis. Glycobiology 2018; 28:32-41. [PMID: 29069438 PMCID: PMC5993100 DOI: 10.1093/glycob/cwx090] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/10/2017] [Accepted: 10/17/2017] [Indexed: 12/15/2022] Open
Abstract
The stem cell niche normally prevents aberrant stem cell behaviors that lead to cancer formation. Recent studies suggest that some cancers are derived from endogenous populations of adult stem cells that have somehow escaped from normal control by the niche. However, the molecular mechanisms by which the niche retains stem cells locally and tightly controls their divisions are poorly understood. Here, we demonstrate that the presence of heparan sulfate (HS), a class glygosaminoglycan chains, in the Drosophila germline stem cell niche prevents tumor formation in the testis. Loss of HS in the niche, called the hub, led to gross changes in the morphology of testes as well as the formation of both somatic and germline tumors. This loss of hub HS resulted in ectopic signaling events in the Jak/Stat pathway outside the niche. This ectopic Jak/Stat signaling disrupted normal somatic cell differentiation, leading to the formation of tumors. Our finding indicates a novel non-autonomous role for niche HS in ensuring the integrity of the niche and preventing tumor formation.
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Affiliation(s)
- Daniel C Levings
- Department of Genetics, Cell Biology and Development, The University of Minnesota, 6-160 Jackson Hall, 321 Church St SE, Minneapolis, MN 55455, USA
| | - Hiroshi Nakato
- Department of Genetics, Cell Biology and Development, The University of Minnesota, 6-160 Jackson Hall, 321 Church St SE, Minneapolis, MN 55455, USA
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31
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Abstract
Gametogenesis represents the most dramatic cellular differentiation pathways in both female and male flies. At the genome level, meiosis ensures that diploid germ cells become haploid gametes. At the epigenome level, extensive changes are required to turn on and shut off gene expression in a precise spatiotemporally controlled manner. Research applying conventional molecular genetics and cell biology, in combination with rapidly advancing genomic tools have helped us to investigate (1) how germ cells maintain lineage specificity throughout their adult reproductive lifetime; (2) what molecular mechanisms ensure proper oogenesis and spermatogenesis, as well as protect genome integrity of the germline; (3) how signaling pathways contribute to germline-soma communication; and (4) if such communication is important. In this chapter, we highlight recent discoveries that have improved our understanding of these questions. On the other hand, restarting a new life cycle upon fertilization is a unique challenge faced by gametes, raising questions that involve intergenerational and transgenerational epigenetic inheritance. Therefore, we also discuss new developments that link changes during gametogenesis to early embryonic development-a rapidly growing field that promises to bring more understanding to some fundamental questions regarding metazoan development.
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32
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The Germline Linker Histone dBigH1 and the Translational Regulator Bam Form a Repressor Loop Essential for Male Germ Stem Cell Differentiation. Cell Rep 2018; 21:3178-3189. [PMID: 29241545 DOI: 10.1016/j.celrep.2017.11.060] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/31/2017] [Accepted: 11/15/2017] [Indexed: 12/13/2022] Open
Abstract
Drosophila spermatogenesis constitutes a paradigmatic system to study maintenance, proliferation, and differentiation of adult stem cell lineages. Each Drosophila testis contains 6-12 germ stem cells (GSCs) that divide asymmetrically to produce gonialblast cells that undergo four transit-amplifying (TA) spermatogonial divisions before entering spermatocyte differentiation. Mechanisms governing these crucial transitions are not fully understood. Here, we report the essential role of the germline linker histone dBigH1 during early spermatogenesis. Our results suggest that dBigH1 is a general silencing factor that represses Bam, a key regulator of spermatogonia proliferation that is silenced in spermatocytes. Reciprocally, Bam represses dBigH1 during TA divisions. This double-repressor mechanism switches dBigH1/Bam expression from off/on in spermatogonia to on/off in spermatocytes, regulating progression into spermatocyte differentiation. dBigH1 is also required for GSC maintenance and differentiation. These results show the critical importance of germline H1s for male GSC lineage differentiation, unveiling a regulatory interaction that couples transcriptional and translational repression.
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33
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Herrera SC, Bach EA. JNK signaling triggers spermatogonial dedifferentiation during chronic stress to maintain the germline stem cell pool in the Drosophila testis. eLife 2018; 7:e36095. [PMID: 29985130 PMCID: PMC6070334 DOI: 10.7554/elife.36095] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 07/06/2018] [Indexed: 12/15/2022] Open
Abstract
Exhaustion of stem cells is a hallmark of aging. In the Drosophila testis, dedifferentiated germline stem cells (GSCs) derived from spermatogonia increase during lifespan, leading to the model that dedifferentiation counteracts the decline of GSCs in aged males. To test this, we blocked dedifferentiation by mis-expressing the differentiation factor bag of marbles (bam) in spermatogonia while lineage-labeling these cells. Strikingly, blocking bam-lineage dedifferentiation under normal conditions in virgin males has no impact on the GSC pool. However, in mated males or challenging conditions, inhibiting bam-lineage dedifferentiation markedly reduces the number of GSCs and their ability to proliferate and differentiate. We find that bam-lineage derived GSCs have significantly higher proliferation rates than sibling GSCs in the same testis. We determined that Jun N-terminal kinase (JNK) activity is autonomously required for bam-lineage dedifferentiation. Overall, we show that dedifferentiation provides a mechanism to maintain the germline and ensure fertility under chronically stressful conditions.
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Affiliation(s)
| | - Erika A Bach
- New York University School of MedicineNew YorkUnited States
- Helen L. and Martin S. Kimmel Center for Stem Cell BiologyNew York University School of MedicineNew YorkUnited States
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34
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Jain D, Puno MR, Meydan C, Lailler N, Mason CE, Lima CD, Anderson KV, Keeney S. ketu mutant mice uncover an essential meiotic function for the ancient RNA helicase YTHDC2. eLife 2018; 7:30919. [PMID: 29360036 PMCID: PMC5832417 DOI: 10.7554/elife.30919] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 01/22/2018] [Indexed: 02/06/2023] Open
Abstract
Mechanisms regulating mammalian meiotic progression are poorly understood. Here we identify mouse YTHDC2 as a critical component. A screen yielded a sterile mutant, ‘ketu’, caused by a Ythdc2 missense mutation. Mutant germ cells enter meiosis but proceed prematurely to aberrant metaphase and apoptosis, and display defects in transitioning from spermatogonial to meiotic gene expression programs. ketu phenocopies mutants lacking MEIOC, a YTHDC2 partner. Consistent with roles in post-transcriptional regulation, YTHDC2 is cytoplasmic, has 3′→5′ RNA helicase activity in vitro, and has similarity within its YTH domain to an N6-methyladenosine recognition pocket. Orthologs are present throughout metazoans, but are diverged in nematodes and, more dramatically, Drosophilidae, where Bgcn is descended from a Ythdc2 gene duplication. We also uncover similarity between MEIOC and Bam, a Bgcn partner unique to schizophoran flies. We propose that regulation of gene expression by YTHDC2-MEIOC is an evolutionarily ancient strategy for controlling the germline transition into meiosis.
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Affiliation(s)
- Devanshi Jain
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, United States
| | - M Rhyan Puno
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, United States.,Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Cem Meydan
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, United States.,The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, United States
| | - Nathalie Lailler
- Integrated Genomics Operation, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Christopher E Mason
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, United States.,The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, United States.,The Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, United States
| | - Christopher D Lima
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, United States.,Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Kathryn V Anderson
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Scott Keeney
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, United States.,Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, United States
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35
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Feng L, Shi Z, Xie J, Ma B, Chen X. Enhancer of polycomb maintains germline activity and genome integrity in Drosophila testis. Cell Death Differ 2018; 25:1486-1502. [PMID: 29362481 DOI: 10.1038/s41418-017-0056-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 11/20/2017] [Accepted: 12/11/2017] [Indexed: 11/09/2022] Open
Abstract
Tissue homeostasis depends on the ability of tissue-specific adult stem cells to maintain a balance between proliferation and differentiation, as well as ensure DNA damage repair. Here, we use the Drosophila male germline stem cell system to study how a chromatin factor, enhancer of polycomb [E(Pc)], regulates the proliferation-to-differentiation (mitosis-to-meiosis) transition and DNA damage repair. We identified two critical targets of E(Pc). First, E(Pc) represses CycB transcription, likely through modulating H4 acetylation. Second, E(Pc) is required for accumulation of an important germline differentiation factor, Bag-of-marbles (Bam), through post-transcriptional regulation. When E(Pc) is downregulated, increased CycB and decreased Bam are both responsible for defective mitosis-to-meiosis transition in the germline. Moreover, DNA double-strand breaks (DSBs) accumulate upon germline inactivation of E(Pc) under both physiological condition and recovery from heat shock-induced endonuclease expression. Failure of robust DSB repair likely leads to germ cell loss. Finally, compromising the activity of Tip60, a histone acetyltransferase, leads to germline defects similar to E(Pc) loss-of-function, suggesting that E(Pc) acts cooperatively with Tip60. Together, our data demonstrate that E(Pc) has pleiotropic roles in maintaining male germline activity and genome integrity. Our findings will help elucidate the in vivo molecular mechanisms of E(Pc).
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Affiliation(s)
- Lijuan Feng
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA.,Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University, New York, NY, 10065, USA
| | - Zhen Shi
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA.,Geometry Technologies LLC, 6-302, 289 Bisheng Lane, Zhangjiang, Shanghai, 201204, China
| | - Jing Xie
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA.,Clinical Research Center for Stem Cell Therapy and Institute for Regenerative Medicine, Shanghai East Hospital; School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Binbin Ma
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA.,Clinical Research Center for Stem Cell Therapy and Institute for Regenerative Medicine, Shanghai East Hospital; School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA.
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36
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Bailey AS, Batista PJ, Gold RS, Chen YG, de Rooij DG, Chang HY, Fuller MT. The conserved RNA helicase YTHDC2 regulates the transition from proliferation to differentiation in the germline. eLife 2017; 6:e26116. [PMID: 29087293 PMCID: PMC5703642 DOI: 10.7554/elife.26116] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 10/29/2017] [Indexed: 12/20/2022] Open
Abstract
The switch from mitosis to meiosis is the key event marking onset of differentiation in the germline stem cell lineage. In Drosophila, the translational repressor Bgcn is required for spermatogonia to stop mitosis and transition to meiotic prophase and the spermatocyte state. Here we show that the mammalian Bgcn homolog YTHDC2 facilitates a clean switch from mitosis to meiosis in mouse germ cells, revealing a conserved role for YTHDC2 in this critical cell fate transition. YTHDC2-deficient male germ cells enter meiosis but have a mixed identity, maintaining expression of Cyclin A2 and failing to properly express many meiotic markers. Instead of continuing through meiotic prophase, the cells attempt an abnormal mitotic-like division and die. YTHDC2 binds multiple transcripts including Ccna2 and other mitotic transcripts, binds specific piRNA precursors, and interacts with RNA granule components, suggesting that proper progression of germ cells through meiosis is licensed by YTHDC2 through post-transcriptional regulation.
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Affiliation(s)
- Alexis S Bailey
- Department of Developmental BiologyStanford University School of MedicineStanfordUnited States
| | - Pedro J Batista
- Center for Personal Dynamic RegulomesStanford University School of MedicineStanfordUnited States
| | - Rebecca S Gold
- Department of Developmental BiologyStanford University School of MedicineStanfordUnited States
| | - Y Grace Chen
- Center for Personal Dynamic RegulomesStanford University School of MedicineStanfordUnited States
| | - Dirk G de Rooij
- Center for Reproductive MedicineAcademic Medical Center, University of AmsterdamAmsterdamNetherlands
| | - Howard Y Chang
- Center for Personal Dynamic RegulomesStanford University School of MedicineStanfordUnited States
| | - Margaret T Fuller
- Department of Developmental BiologyStanford University School of MedicineStanfordUnited States
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37
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Napoletano F, Gibert B, Yacobi-Sharon K, Vincent S, Favrot C, Mehlen P, Girard V, Teil M, Chatelain G, Walter L, Arama E, Mollereau B. p53-dependent programmed necrosis controls germ cell homeostasis during spermatogenesis. PLoS Genet 2017; 13:e1007024. [PMID: 28945745 PMCID: PMC5629030 DOI: 10.1371/journal.pgen.1007024] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 10/05/2017] [Accepted: 09/15/2017] [Indexed: 01/02/2023] Open
Abstract
The importance of regulated necrosis in pathologies such as cerebral stroke and myocardial infarction is now fully recognized. However, the physiological relevance of regulated necrosis remains unclear. Here, we report a conserved role for p53 in regulating necrosis in Drosophila and mammalian spermatogenesis. We found that Drosophila p53 is required for the programmed necrosis that occurs spontaneously in mitotic germ cells during spermatogenesis. This form of necrosis involved an atypical function of the initiator caspase Dronc/Caspase 9, independent of its catalytic activity. Prevention of p53-dependent necrosis resulted in testicular hyperplasia, which was reversed by restoring necrosis in spermatogonia. In mouse testes, p53 was required for heat-induced germ cell necrosis, indicating that regulation of necrosis is a primordial function of p53 conserved from invertebrates to vertebrates. Drosophila and mouse spermatogenesis will thus be useful models to identify inducers of necrosis to treat cancers that are refractory to apoptosis.
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Affiliation(s)
- Francesco Napoletano
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Benjamin Gibert
- Apoptosis, Cancer and Development Laboratory- Equipe labellisée ‘La Ligue’, LabEx DEVweCAN, Centre de Cancérologie de Lyon, INSERM U1052-CNRS UMR5286, Université de Lyon, Centre Léon Bérard, Lyon, France
| | - Keren Yacobi-Sharon
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Stéphane Vincent
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Clémentine Favrot
- Apoptosis, Cancer and Development Laboratory- Equipe labellisée ‘La Ligue’, LabEx DEVweCAN, Centre de Cancérologie de Lyon, INSERM U1052-CNRS UMR5286, Université de Lyon, Centre Léon Bérard, Lyon, France
| | - Patrick Mehlen
- Apoptosis, Cancer and Development Laboratory- Equipe labellisée ‘La Ligue’, LabEx DEVweCAN, Centre de Cancérologie de Lyon, INSERM U1052-CNRS UMR5286, Université de Lyon, Centre Léon Bérard, Lyon, France
| | - Victor Girard
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Margaux Teil
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Gilles Chatelain
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Ludivine Walter
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Eli Arama
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Bertrand Mollereau
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
- * E-mail:
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Eun SH, Feng L, Cedeno-Rosario L, Gan Q, Wei G, Cui K, Zhao K, Chen X. Polycomb Group Gene E(z) Is Required for Spermatogonial Dedifferentiation in Drosophila Adult Testis. J Mol Biol 2017; 429:2030-2041. [PMID: 28434938 PMCID: PMC5516936 DOI: 10.1016/j.jmb.2017.04.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/30/2017] [Accepted: 04/17/2017] [Indexed: 12/12/2022]
Abstract
Dedifferentiation is an important process to replenish lost stem cells during aging or regeneration after injury to maintain tissue homeostasis. Here, we report that Enhancer of Zeste [E(z)], a component of the Polycomb repression complex 2 (PRC2), is required to maintain a stable pool of germline stem cells (GSCs) within the niche microenvironment. During aging, germ cells with reduced E(z) activity cannot meet that requirement, but the defect arises from neither increased GSC death nor premature differentiation. Instead, we found evidence that the decrease of GSCs upon the inactivation of E(z) in the germline could be attributed to defective dedifferentiation. During recovery from genetically manipulated GSC depletion, E(z) knockdown germ cells also fail to replenish lost GSCs. Taken together, our data suggest that E(z) acts intrinsically in germ cells to activate dedifferentiation and thus replenish lost GSCs during both aging and tissue regeneration.
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Affiliation(s)
- Suk Ho Eun
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Lijuan Feng
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Luis Cedeno-Rosario
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Qiang Gan
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Gang Wei
- Laboratory of Molecular Immunology, National Heart, Lung and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Kairong Cui
- Laboratory of Molecular Immunology, National Heart, Lung and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Keji Zhao
- Laboratory of Molecular Immunology, National Heart, Lung and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA.
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Bam and Otu can regulate stem cell fate by stabilizing cyclin A. Proc Natl Acad Sci U S A 2017; 114:6154-6156. [PMID: 28584130 DOI: 10.1073/pnas.1706840114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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40
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Control of a Novel Spermatocyte-Promoting Factor by the Male Germline Sex Determination Factor PHF7 of Drosophila melanogaster. Genetics 2017; 206:1939-1949. [PMID: 28588035 DOI: 10.1534/genetics.117.199935] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 05/18/2017] [Indexed: 12/20/2022] Open
Abstract
A key aspect of germ cell development is to establish germline sexual identity and initiate a sex-specific developmental program to promote spermatogenesis or oogenesis. Previously, we have identified the histone reader Plant Homeodomain Finger 7 (PHF7) as an important regulator of male germline identity. To understand how PHF7 directs sexual differentiation of the male germline, we investigated the downstream targets of PHF7 by combining transcriptome analyses, which reveal genes regulated by Phf7, with genomic profiling of histone H3K4me2, the chromatin mark that is bound by PHF7. Through these genomic experiments, we identify a novel spermatocyte factor Receptor Accessory Protein Like 1 (REEPL1) that can promote spermatogenesis and whose expression is kept off by PHF7 in the spermatogonial stage. Loss of Reepl1 significantly rescues the spermatogenesis defects in Phf7 mutants, indicating that regulation of Reepl1 is an essential aspect of PHF7 function. Further, increasing REEPL1 expression facilitates spermatogenic differentiation. These results indicate that PHF7 controls spermatogenesis by regulating the expression patterns of important male germline genes.
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Gupta S, Ray K. Somatic PI3K activity regulates transition to the spermatocyte stages in Drosophila testis. J Biosci 2017; 42:285-297. [PMID: 28569252 DOI: 10.1007/s12038-017-9678-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Spermatogenesis, involving multiple transit amplification divisions and meiosis, occurs within an enclosure formed by two somatic cells. As the cohort of germline cells divide and grow, the surface areas of the somatic cells expand maintaining a tight encapsulation throughout the developmental period. Correlation between the somatic cell growth and germline development is unclear. Here, we report standardization of a quantitative assay developed for estimating the somatic roles of target molecules on germline division and differentiation in Drosophila testis. Using the assay, we studied the somatic roles of phosphatidylinositol-3-kinase (PI3K). It revealed that the expression of PI3KDN is likely to facilitate the early germline development at all stages, and an increase in the somatic PI3K activity during the early stages delays the transition to spermatocyte stage. Together, these results suggest that somatic cell growth plays an important role in regulating the rate of germline development.
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Affiliation(s)
- Samir Gupta
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400 005, India
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Kim J, Lu C, Srinivasan S, Awe S, Brehm A, Fuller MT. Blocking promiscuous activation at cryptic promoters directs cell type-specific gene expression. Science 2017; 356:717-721. [PMID: 28522526 PMCID: PMC5572561 DOI: 10.1126/science.aal3096] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 04/13/2017] [Indexed: 12/18/2022]
Abstract
To selectively express cell type-specific transcripts during development, it is critical to maintain genes required for other lineages in a silent state. Here, we show in the Drosophila male germline stem cell lineage that a spermatocyte-specific zinc finger protein, Kumgang (Kmg), working with the chromatin remodeler dMi-2 prevents transcription of genes normally expressed only in somatic lineages. By blocking transcription from normally cryptic promoters, Kmg restricts activation by Aly, a component of the testis-meiotic arrest complex, to transcripts for male germ cell differentiation. Our results suggest that as new regions of the genome become open for transcription during terminal differentiation, blocking the action of a promiscuous activator on cryptic promoters is a critical mechanism for specifying precise gene activation.
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Affiliation(s)
- Jongmin Kim
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305-5329, USA
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305-5329, USA
| | - Chenggang Lu
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305-5329, USA
| | - Shrividhya Srinivasan
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305-5329, USA
| | - Stephan Awe
- Institut für Molekularbiologie und Tumorforschung, Philipps-Universität Marburg, Marburg, Germany
| | - Alexander Brehm
- Institut für Molekularbiologie und Tumorforschung, Philipps-Universität Marburg, Marburg, Germany
| | - Margaret T Fuller
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305-5329, USA.
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305-5329, USA
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Soh YQS, Mikedis MM, Kojima M, Godfrey AK, de Rooij DG, Page DC. Meioc maintains an extended meiotic prophase I in mice. PLoS Genet 2017; 13:e1006704. [PMID: 28380054 PMCID: PMC5397071 DOI: 10.1371/journal.pgen.1006704] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/19/2017] [Accepted: 03/20/2017] [Indexed: 01/13/2023] Open
Abstract
The meiosis-specific chromosomal events of homolog pairing, synapsis, and recombination occur over an extended meiotic prophase I that is many times longer than prophase of mitosis. Here we show that, in mice, maintenance of an extended meiotic prophase I requires the gene Meioc, a germ-cell specific factor conserved in most metazoans. In mice, Meioc is expressed in male and female germ cells upon initiation of and throughout meiotic prophase I. Mouse germ cells lacking Meioc initiate meiosis: they undergo pre-meiotic DNA replication, they express proteins involved in synapsis and recombination, and a subset of cells progress as far as the zygotene stage of prophase I. However, cells in early meiotic prophase—as early as the preleptotene stage—proceed to condense their chromosomes and assemble a spindle, as if having progressed to metaphase. Meioc-deficient spermatocytes that have initiated synapsis mis-express CYCLIN A2, which is normally expressed in mitotic spermatogonia, suggesting a failure to properly transition to a meiotic cell cycle program. MEIOC interacts with YTHDC2, and the two proteins pull-down an overlapping set of mitosis-associated transcripts. We conclude that when the meiotic chromosomal program is initiated, Meioc is simultaneously induced so as to extend meiotic prophase. Specifically, MEIOC, together with YTHDC2, promotes a meiotic (as opposed to mitotic) cell cycle program via post-transcriptional control of their target transcripts. Meiosis is the specialized cell division that halves the genetic content of germ cells to produce haploid gametes. This reductive division is preceded by a preparative phase of the cell cycle, meiotic prophase I, during which several meiosis-specific chromosomal events occur. Across sexually reproducing organisms, prophase of meiosis I is dramatically longer than mitotic prophase. However, it was not known in mammals how and why meiotic prophase I is extended. We have identified a mouse mutant in which this extended prophase I is disrupted: germ cells lacking Meioc initiate meiosis, but prematurely proceed to metaphase. Mutant male meiotic germ cells mis-express a cell cycle regulator that is normally expressed in mitotic male germ cells, suggesting that Meioc is required for germ cells to properly transition to a meiotic cell cycle program. Biochemical analyses of proteins and transcripts that associate with MEIOC protein suggest that MEIOC may promote the transition from a mitotic to meiotic cell cycle program by post-transcriptionally regulating target transcripts. Our studies indicate that in mammals, as in other sexually reproducing organisms, meiotic prophase I must be extended to allow time for meiotic chromosomal events to reach completion.
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Affiliation(s)
- Y. Q. Shirleen Soh
- Whitehead Institute, Cambridge, MA, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | | | - Mina Kojima
- Whitehead Institute, Cambridge, MA, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Alexander K. Godfrey
- Whitehead Institute, Cambridge, MA, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | | | - David C. Page
- Whitehead Institute, Cambridge, MA, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA, United States of America
- * E-mail:
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Feng L, Shi Z, Chen X. Enhancer of polycomb coordinates multiple signaling pathways to promote both cyst and germline stem cell differentiation in the Drosophila adult testis. PLoS Genet 2017; 13:e1006571. [PMID: 28196077 PMCID: PMC5308785 DOI: 10.1371/journal.pgen.1006571] [Citation(s) in RCA: 21] [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: 11/21/2016] [Accepted: 01/04/2017] [Indexed: 12/31/2022] Open
Abstract
Stem cells reside in a particular microenvironment known as a niche. The interaction between extrinsic cues originating from the niche and intrinsic factors in stem cells determines their identity and activity. Maintenance of stem cell identity and stem cell self-renewal are known to be controlled by chromatin factors. Herein, we use the Drosophila adult testis which has two adult stem cell lineages, the germline stem cell (GSC) lineage and the cyst stem cell (CySC) lineage, to study how chromatin factors regulate stem cell differentiation. We find that the chromatin factor Enhancer of Polycomb [E(Pc)] acts in the CySC lineage to negatively control transcription of genes associated with multiple signaling pathways, including JAK-STAT and EGF, to promote cellular differentiation in the CySC lineage. E(Pc) also has a non-cell-autonomous role in regulating GSC lineage differentiation. When E(Pc) is specifically inactivated in the CySC lineage, defects occur in both germ cell differentiation and maintenance of germline identity. Furthermore, compromising Tip60 histone acetyltransferase activity in the CySC lineage recapitulates loss-of-function phenotypes of E(Pc), suggesting that Tip60 and E(Pc) act together, consistent with published biochemical data. In summary, our results demonstrate that E(Pc) plays a central role in coordinating differentiation between the two adult stem cell lineages in Drosophila testes. Tissue maintenance and repair rely on adult stem cells, which can divide to generate new stem cells as well as cells committed for becoming specific cell types. Stem cell activity needs to be tightly controlled because insufficient or unlimited stem cell division may lead to tissue degeneration or tumorigenesis. This control depends not only on stem cells themselves, but also on the microenvironment where stem cells reside. The chromatin structure of stem cells is crucial to determine their activities. The signaling pathways connecting stem cells with their microenvironment is also important. Here we ask how chromatin factors interact with signaling pathways in determining stem cell activity. We use Drosophila adult testis as a model system, in which two types of stem cells co-exist and interact: germline stem cells and somatic stem cells. We find that a chromatin regulator called Enhancer of Polycomb [E(Pc)] acts in somatic cells to promote germ cell differentiation and maintain germ cell fate. This regulation is mediated by several signaling pathways, such as EGF and JAK-STAT pathways. E(Pc) also works with another chromatin regulator, the histone acetyltransferase Tip60, in somatic cells. Insufficient activity of the E(Pc) homolog in human leads to cancers. Our studies of E(Pc) may help understanding its roles as a tumor suppressor.
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Affiliation(s)
- Lijuan Feng
- Department of Biology, The Johns Hopkins University, Baltimore, MD, United States of America
| | - Zhen Shi
- Department of Biology, The Johns Hopkins University, Baltimore, MD, United States of America
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD, United States of America
- * E-mail:
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45
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Estrogen related receptor is required for the testicular development and for the normal sperm axoneme/mitochondrial derivatives in Drosophila males. Sci Rep 2017; 7:40372. [PMID: 28094344 PMCID: PMC5240334 DOI: 10.1038/srep40372] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 12/06/2016] [Indexed: 12/22/2022] Open
Abstract
Estrogen related receptors (ERRs), categorized as orphan nuclear receptors, are critical for energy homeostasis and somatic development. However, significance of ERRs in the development of reproductive organs/organelles/cells remain poorly understood, albeit their homology to estrogen receptors. In this context, here, we show that knockdown of ERR in the testes leads to improperly developed testes with mis-regulation of genes (aly, mia, bruce, bam, bgcn, fzo and eya) involved in spermatogenesis, resulting in reduced male fertility. The observed testicular deformity is consistent with the down-regulation of SOX-E group of gene (SOX100B) in Drosophila. We also show dispersion/disintegration of fusomes (microtubule based structures associated with endoplasmic reticulum derived vesicle, interconnecting spermatocytes) in ERR knockdown testes. A few ERR knockdown testes go through spermatogenesis but have significantly fewer sperm. Moreover, flagella of these sperm are defective with abnormal axoneme and severely reduced mitochondrial derivatives, suggesting a possible role for ERR in mitochondrial biogenesis, analogous to mammalian ERRα. Interestingly, similar knockdown of remaining seventeen nuclear receptors did not yield a detectable reproductive or developmental defect in Drosophila. These findings add newer dimensions to the functions envisaged for ERR and provide the foundation for deciphering the relevance of orphan nuclear receptors in ciliopathies and testicular dysgenesis.
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46
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Johnston MJ, Bar-Cohen S, Paroush Z, Nystul TG. Phosphorylated Groucho delays differentiation in the follicle stem cell lineage by providing a molecular memory of EGFR signaling in the niche. Development 2016; 143:4631-4642. [PMID: 27836963 PMCID: PMC5201033 DOI: 10.1242/dev.143263] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 10/31/2016] [Indexed: 01/03/2023]
Abstract
In the epithelial follicle stem cells (FSCs) of the Drosophila ovary, Epidermal Growth Factor Receptor (EGFR) signaling promotes self-renewal, whereas Notch signaling promotes differentiation of the prefollicle cell (pFC) daughters. We have identified two proteins, Six4 and Groucho (Gro), that link the activity of these two pathways to regulate the earliest cell fate decision in the FSC lineage. Our data indicate that Six4 and Gro promote differentiation towards the polar cell fate by promoting Notch pathway activity. This activity of Gro is antagonized by EGFR signaling, which inhibits Gro-dependent repression via p-ERK mediated phosphorylation. We have found that the phosphorylated form of Gro persists in newly formed pFCs, which may delay differentiation and provide these cells with a temporary memory of the EGFR signal. Collectively, these findings demonstrate that phosphorylated Gro labels a transition state in the FSC lineage and describe the interplay between Notch and EGFR signaling that governs the differentiation processes during this period.
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Affiliation(s)
- Michael J Johnston
- The University of California, San Francisco, Departments of Anatomy and OB-GYN/RS, CA 94122, USA
| | - Shaked Bar-Cohen
- The Hebrew University, Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, Jerusalem 9112102, Israel
| | - Ze'ev Paroush
- The Hebrew University, Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, Jerusalem 9112102, Israel
| | - Todd G Nystul
- The University of California, San Francisco, Departments of Anatomy and OB-GYN/RS, CA 94122, USA
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Yu J, Liu Y, Lan X, Wu H, Wen Y, Zhou Z, Hu Z, Sha J, Guo X, Tong C. CHES-1-like, the ortholog of a non-obstructive azoospermia-associated gene, blocks germline stem cell differentiation by upregulating Dpp expression in Drosophila testis. Oncotarget 2016; 7:42303-42313. [PMID: 27281616 PMCID: PMC5173136 DOI: 10.18632/oncotarget.9789] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 05/16/2016] [Indexed: 12/26/2022] Open
Abstract
Azoospermia is a high risk factor for testicular germ cell tumors, whose underlying molecular mechanisms remain unknown. In a genome-wide association study to identify novel loci associated with human non-obstructive azoospermia (NOA), we uncovered a single nucleotide polymorphism (rs1887102, P=2.60 ×10-7) in a human gene FOXN3. FOXN3 is an evolutionarily conserved gene. We used Drosophila melanogaster as a model system to test whether CHES-1-like, the Drosophila FOXN3 ortholog, is required for male fertility. CHES-1-like knockout flies are viable and fertile, and show no defects in spermatogenesis. However, ectopic expression of CHES-1-like in germ cells significantly reduced male fertility. With CHES-1-like overexpression, spermatogonia fail to differentiate after four rounds of mitotic division, but continue to divide to form tumor like structures. In these testes, expression levels of differentiation factor, Bam, were reduced, but the expression region of Bam was expanded. Further reduced Bam expression in CHES-1-like expressing testes exhibited enhanced tumor-like structure formation. The expression of daughters against dpp (dad), a downstream gene of dpp signaling, was upregulated by CHES-1-like expression in testes. We found that CHES-1-like could directly bind to the dpp promoter. We propose a model that CHES-1-like overexpression in germ cells activates dpp expression, inhibits spermatocyte differentiation, and finally leads to germ cell tumors.
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Affiliation(s)
- Jun Yu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
- Department of Histology and Embryology, Nanjing Medical University, Nanjing 211166, China
| | - Yujuan Liu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
- Department of Histology and Embryology, Nanjing Medical University, Nanjing 211166, China
| | - Xiang Lan
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou 310058, China
| | - Hao Wu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
- Department of Histology and Embryology, Nanjing Medical University, Nanjing 211166, China
| | - Yang Wen
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Zuomin Zhou
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
- Department of Histology and Embryology, Nanjing Medical University, Nanjing 211166, China
| | - Zhibin Hu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Jiahao Sha
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
- Department of Histology and Embryology, Nanjing Medical University, Nanjing 211166, China
| | - Xuejiang Guo
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
- Department of Histology and Embryology, Nanjing Medical University, Nanjing 211166, China
- Animal Core Facility, Nanjing Medical University, Nanjing 211166, China
| | - Chao Tong
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou 310058, China
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Quénerch'du E, Anand A, Kai T. The piRNA pathway is developmentally regulated during spermatogenesis in Drosophila. RNA (NEW YORK, N.Y.) 2016; 22:1044-1054. [PMID: 27208314 PMCID: PMC4911912 DOI: 10.1261/rna.055996.116] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/15/2016] [Indexed: 06/02/2023]
Abstract
PIWI-interacting RNAs (piRNAs) are predominantly produced in animal gonads to suppress transposons during germline development. Our understanding about the piRNA biogenesis and function is predominantly from studies of the Drosophila female germline. piRNA pathway function in the male germline, however, remains poorly understood. To study overall and stage-specific features of piRNAs during spermatogenesis, we analyzed small RNAs extracted from entire wild-type testes and stage-specific arrest mutant testes enriched with spermatogonia or primary spermatocytes. We show that most active piRNA clusters in the female germline do not majorly contribute to piRNAs in testes, and abundance patterns of piRNAs mapping to different transposon families also differ between male and female germlines. piRNA production is regulated in a stage-specific manner during spermatogenesis. The piRNAs in spermatogonia-enriched testes are predominantly transposon-mapping piRNAs, and almost half of those exhibit a ping-pong signature. In contrast, the primary spermatocyte-enriched testes have a dramatically high amount of piRNAs targeting repeats like suppressor of stellate and AT-chX The transposon-mapping piRNAs in the primary spermatocyte stages lacking Argonaute3 expression also show a ping-pong signature, albeit to a lesser extent. Consistently, argonaute3 mutant testes also retain ping-pong signature-bearing piRNAs, suggesting that a noncanonical ping-pong cycle might act during spermatogenesis. Our study shows stage-specific regulation of piRNA biogenesis during spermatogenesis: An active ping-pong cycle produces abundant transposon-mapping piRNAs in spermatogonia, while in primary spermatocytes, piRNAs act to suppress the repeats and transposons.
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Affiliation(s)
- Emilie Quénerch'du
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604 Singapore, Singapore Department of Biological Sciences, National University of Singapore, 117543 Singapore, Singapore
| | - Amit Anand
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604 Singapore, Singapore
| | - Toshie Kai
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604 Singapore, Singapore
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Eikenes ÅH, Malerød L, Lie-Jensen A, Sem Wegner C, Brech A, Liestøl K, Stenmark H, Haglund K. Src64 controls a novel actin network required for proper ring canal formation in the Drosophila male germline. Development 2016; 142:4107-18. [PMID: 26628094 DOI: 10.1242/dev.124370] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In many organisms, germ cells develop as cysts in which cells are interconnected via ring canals (RCs) as a result of incomplete cytokinesis. However, the molecular mechanisms of incomplete cytokinesis remain poorly understood. Here, we address the role of tyrosine phosphorylation of RCs in the Drosophila male germline. We uncover a hierarchy of tyrosine phosphorylation within germline cysts that positively correlates with RC age. The kinase Src64 is responsible for mediating RC tyrosine phosphorylation, and loss of Src64 causes a reduction in RC diameter within germline cysts. Mechanistically, we show that Src64 controls an actin network around the RCs that depends on Abl and the Rac/SCAR/Arp2/3 pathway. The actin network around RCs is required for correct RC diameter in cysts of developing germ cells. We also identify that Src64 is required for proper germ cell differentiation in the Drosophila male germline independent of its role in RC regulation. In summary, we report that Src64 controls actin dynamics to mediate proper RC formation during incomplete cytokinesis during germline cyst development in vivo.
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Affiliation(s)
- Åsmund Husabø Eikenes
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Lene Malerød
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Anette Lie-Jensen
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Catherine Sem Wegner
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Andreas Brech
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Knut Liestøl
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway Department of Informatics, University of Oslo, Oslo N-0316, Norway
| | - Harald Stenmark
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Kaisa Haglund
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
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Ong C, Lee QY, Cai Y, Liu X, Ding J, Yung LYL, Bay BH, Baeg GH. Silver nanoparticles disrupt germline stem cell maintenance in the Drosophila testis. Sci Rep 2016; 6:20632. [PMID: 26847594 PMCID: PMC4742918 DOI: 10.1038/srep20632] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/06/2016] [Indexed: 02/08/2023] Open
Abstract
Silver nanoparticles (AgNPs), one of the most popular nanomaterials, are commonly used in consumer products and biomedical devices, despite their potential toxicity. Recently, AgNP exposure was reported to be associated with male reproductive toxicity in mammalian models. However, there is still a limited understanding of the effects of AgNPs on spermatogenesis. The fruit fly Drosophila testis is an excellent in vivo model to elucidate the mechanisms underlying AgNP-induced defects in spermatogenesis, as germ lineages can be easily identified and imaged. In this study, we evaluated AgNP-mediated toxicity on spermatogenesis by feeding Drosophila with AgNPs at various concentrations. We first observed a dose-dependent uptake of AgNPs in vivo. Concomitantly, AgNP exposure caused a significant decrease in the viability and delay in the development of Drosophila in a dose-dependent manner. Furthermore, AgNP-treated male flies showed a reduction in fecundity, and the resulting testes contained a decreased number of germline stem cells (GSCs) compared to controls. Interestingly, testes exposed to AgNPs exhibited a dramatic increase in reactive oxygen species levels and showed precocious GSC differentiation. Taken together, our study suggests that AgNP exposure may increase ROS levels in the Drosophila testis, leading to a reduction of GSC number by promoting premature GSC differentiation.
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Affiliation(s)
- Cynthia Ong
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117594, Singapore
| | - Qian Ying Lee
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117594, Singapore
| | - Yu Cai
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Xiaoli Liu
- Department of Materials Science &Engineering, Faculty of Engineering, National University of Singapore, 7 Engineering Drive 1, 117574, Singapore
| | - Jun Ding
- Department of Materials Science &Engineering, Faculty of Engineering, National University of Singapore, 7 Engineering Drive 1, 117574, Singapore
| | - Lin-Yue Lanry Yung
- Department of Chemical &Biomolecular Engineering, Faculty of Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Boon-Huat Bay
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117594, Singapore
| | - Gyeong-Hun Baeg
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117594, Singapore
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