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Gadre P, Chatterjee S, Varshney B, Ray K. Cyclin E and Cdk1 regulate the termination of germline transit-amplification process in Drosophila testis. Cell Cycle 2020; 19:1786-1803. [PMID: 32573329 DOI: 10.1080/15384101.2020.1780381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
An extension of the G1 is correlated with stem cell differentiation. The role of cell cycle regulation during the subsequent transit amplification (TA) divisions is, however, unclear. Here, we report for the first time that in the Drosophila male germline lineage, the transit amplification divisions accelerate after the second TA division. The cell cycle phases, marked by Cyclin E and Cyclin B, are progressively altered during the TA. Antagonistic functions of the bag-of-marbles and the Transforming-Growth-Factor-β signaling regulate the cell division rates after the second TA division and the extent of the Cyclin E phase during the fourth TA division. Furthermore, loss of Cyclin E during the fourth TA cycle retards the cell division and induces premature meiosis in some cases. A similar reduction of Cdk1 activity during this stage arrests the penultimate division and subsequent differentiation, whereas enhancement of the Cdk1 activity prolongs the TA by one extra round. Altogether, the results suggest that modification of the cell cycle structure and the rates of cell division after the second TA division determine the extent of amplification. Also, the regulation of the Cyclin E and CDK1 functions during the penultimate TA division determines the induction of meiosis and subsequent differentiation.
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Affiliation(s)
- Purna Gadre
- Department of Biological Sciences, Tata Institute of Fundamental Research , Mumbai, India
| | - Shambhabi Chatterjee
- Department of Biological Sciences, Tata Institute of Fundamental Research , Mumbai, India
| | - Bhavna Varshney
- Department of Biological Sciences, Tata Institute of Fundamental Research , Mumbai, India
| | - Krishanu Ray
- Department of Biological Sciences, Tata Institute of Fundamental Research , Mumbai, India
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Ceyhan Y, Zhang M, Guo J, Sandoval CG, Vacher J, Kaftanovskaya EM, Agoulnik AI, Agoulnik IU. Deletion of inositol polyphosphate 4-phosphatase type-II B affects spermatogenesis in mice. PLoS One 2020; 15:e0233163. [PMID: 32413098 PMCID: PMC7228085 DOI: 10.1371/journal.pone.0233163] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 04/29/2020] [Indexed: 12/12/2022] Open
Abstract
Inositol polyphosphate-4-phosphatase type II (INPP4B) is a dual-specificity phosphatase that acts as a tumor suppressor in multiple cancers. INPP4B dephosphorylates phospholipids at the 4th position of the inositol ring and inhibits AKT and PKC signaling by hydrolyzing of PI(3,4)P2 and PI(4,5)P2, respectively. INPP4B protein phosphatase targets include phospho-tyrosines on Akt and phospho-serine and phospho-threonine on PTEN. INPP4B is highly expressed in testes, suggesting its role in testes development and physiology. The objective of this study was to determine whether Inpp4b deletion impacts testicular function in mice. In testis, Inpp4b expression was the highest in postmeiotic germ cells in both mice and men. The testes of Inpp4b knockout male mice were significantly smaller compared to the testes of wild-type (WT) males. Inpp4b-/- males produced fewer mature sperm cells compared to WT, and this difference increased with age and high fat diet (HFD). Reduction in early steroidogenic enzymes and luteinizing hormone (LH) receptor gene expression was detected, although androgen receptor (AR) protein level was similar in WT and Inpp4b-/- testes. Germ cell apoptosis was significantly increased in the knockout mice, while expression of meiotic marker γH2A.X was decreased. Our data demonstrate that INPP4B plays a role in maintenance of male germ cell differentiation and protects testis functions against deleterious effects of aging and high fat diet.
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Affiliation(s)
- Yasemin Ceyhan
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States of America
| | - Manqi Zhang
- Division of Medical Oncology, Department of Medicine, Duke University, Durham, NC, United States of America
| | - Jingtao Guo
- Department of Oncological Sciences and Huntsman Cancer Institute, Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT, United States of America
- Department of Surgery (Andrology/Urology), Center for Reconstructive Urology and Men’s Health, University of Utah Health Sciences Center, Salt Lake City, UT, United States of America
| | - Carlos G. Sandoval
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States of America
| | - Jean Vacher
- Department of Medicine, Institut de Recherches Cliniques de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Elena M. Kaftanovskaya
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States of America
| | - Alexander I. Agoulnik
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States of America
- Biomolecular Science Institute, Florida International University, Miami, FL, United States of America
| | - Irina U. Agoulnik
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States of America
- Biomolecular Science Institute, Florida International University, Miami, FL, United States of America
- * E-mail:
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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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