1. Rbf Regulates Drosophila Spermatogenesis via Control of Somatic Stem and Progenitor Cell Fate in the Larval Testis
- Author
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Fengwei Yu, Nicole A Siddall, Mai Tran, Yu Cai, Hongyan Wang, Leonie M. Quinn, Nicole Dominado, John E. La Marca, W. Gregory Somers, James Heaney, and Gary R. Hime
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Male ,0301 basic medicine ,Somatic cell ,proliferation ,Cellular differentiation ,testis ,retinoblastoma protein ,self-renewal ,germline ,medicine.disease_cause ,Biochemistry ,Article ,Germline ,03 medical and health sciences ,0302 clinical medicine ,Genetics ,medicine ,Animals ,Drosophila Proteins ,Cell Lineage ,stem cell niche ,Progenitor cell ,Spermatogenesis ,reproductive and urinary physiology ,Cell Proliferation ,Uncategorized ,Mutation ,biology ,urogenital system ,Stem Cells ,Retinoblastoma protein ,Cell Differentiation ,Cell Biology ,Null allele ,stem cell ,Drosophila melanogaster ,Germ Cells ,030104 developmental biology ,Larva ,biology.protein ,Drosophila ,Stem cell ,030217 neurology & neurosurgery ,Transcription Factors ,circulatory and respiratory physiology ,Developmental Biology - Abstract
Summary The Drosophila testis has been fundamental to understanding how stem cells interact with their endogenous microenvironment, or niche, to control organ growth in vivo. Here, we report the identification of two independent alleles for the highly conserved tumor suppressor gene, Retinoblastoma-family protein (Rbf), in a screen for testis phenotypes in X chromosome third-instar lethal alleles. Rbf mutant alleles exhibit overproliferation of spermatogonial cells, which is phenocopied by the molecularly characterized Rbf11 null allele. We demonstrate that Rbf promotes cell-cycle exit and differentiation of the somatic and germline stem cells of the testes. Intriguingly, depletion of Rbf specifically in the germline does not disrupt stem cell differentiation, rather Rbf loss of function in the somatic lineage drives overproliferation and differentiation defects in both lineages. Together our observations suggest that Rbf in the somatic lineage controls germline stem cell renewal and differentiation non-autonomously via essential roles in the microenvironment of the germline lineage., Graphical Abstract, Highlights • Rbf null testes exhibit failure of germline stem cells to differentiate • Rbf expression in somatic cells of L3 testes rescues the GSC differentiation defect • Somatic Rbf RNAi disrupts cyst stem cell and germline stem cell differentiation • Somatic depletion of E2f1 rescues Rbf germline proliferation and differentiation, The Drosophila testis contains germline and somatic cyst stem cell populations. Progeny from these populations cross regulate the differentiation of each lineage. In this article, Hime, Quinn, and colleagues show that the Drosophila Retinoblastoma ortholog, Rbf, is cell autonomously required by somatic cells of the testis to facilitate cyst stem cell differentiation and subsequent germline stem cell differentiation.
- Published
- 2023
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