A novel group of pumilio mutations affects the asymmetric division of germline stem cells in the Drosophila ovary

Development ◽  
1997 ◽  
Vol 124 (12) ◽  
pp. 2463-2476 ◽  
Author(s):  
H. Lin ◽  
A.C. Spradling
Keyword(s):  
Stem Cells ◽  
Target Genes ◽  
Germ Line ◽  
Asymmetric Division ◽  
Germline Stem Cell ◽  
Germline Stem Cells ◽  
Similar Activity ◽  
Cytoplasmic Structure ◽  
Stem Cell Division ◽  
Drosophila Ovary

Germline stem cells play a pivotal role in gametogenesis; yet little is known about how they are formed, how they divide to self-renew, and how these processes are genetically controlled. Here we describe the self-renewing asymmetric division of germline stem cells in the Drosophila ovarian germline, as marked by the spectrosome, a cytoplasmic structure rich in membrane skeletal proteins. The ontogeny of the spectrosome marks the lineage of germline stem cells. We identified two new groups of mutations in which the divisional asymmetry is disrupted. The first, which we refer to as ovarette (ovt) mutations, was shown to correspond to a novel class of mutations in the pumilio locus. Since pumilio is known to posttranscriptionally repress the expression of target genes at earlier stages of germ cell development, our results suggest that a similar activity is needed to maintain germ line stem cells. We have also identified a second and novel gene, piwi, whose mutations abolish germline stem cell division.

scholarly journals Heparan sulfate regulates the number and centrosome positioning of Drosophila male germline stem cells

2016 ◽  
Vol 27 (6) ◽  
pp. 888-896 ◽  
Author(s):  
Daniel C. Levings ◽  
Takeshi Arashiro ◽  
Hiroshi Nakato
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Heparan Sulfate ◽  
Molecular Mechanisms ◽  
Asymmetric Division ◽  
Germline Stem Cells ◽  
Cell Behaviors ◽  
Male Germline ◽  
Drosophila Testis ◽  
Stem Cell Division

Stem cell division is tightly controlled via secreted signaling factors and cell adhesion molecules provided from local niche structures. Molecular mechanisms by which each niche component regulates stem cell behaviors remain to be elucidated. Here we show that heparan sulfate (HS), a class of glycosaminoglycan chains, regulates the number and asymmetric division of germline stem cells (GSCs) in the Drosophila testis. We found that GSC number is sensitive to the levels of 6- O sulfate groups on HS. Loss of 6- O sulfation also disrupted normal positioning of centrosomes, a process required for asymmetric division of GSCs. Blocking HS sulfation specifically in the niche, termed the hub, led to increased GSC numbers and mispositioning of centrosomes. The same treatment also perturbed the enrichment of Apc2, a component of the centrosome-anchoring machinery, at the hub–GSC interface. This perturbation of the centrosome-anchoring process ultimately led to an increase in the rate of spindle misorientation and symmetric GSC division. This study shows that specific HS modifications provide a novel regulatory mechanism for stem cell asymmetric division. The results also suggest that HS-mediated niche signaling acts upstream of GSC division orientation control.

scholarly journals Centrosome-dependent asymmetric inheritance of the midbody ring in Drosophila germline stem cell division

2014 ◽  
Vol 25 (2) ◽  
pp. 267-275 ◽  
Author(s):  
Viktoria Salzmann ◽  
Cuie Chen ◽  
C.-Y. Ason Chiang ◽  
Amita Tiyaboonchai ◽  
Michael Mayer ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Germline Stem Cell ◽  
Dependent Manner ◽  
Germline Stem Cells ◽  
Cell Identity ◽  
Dividing Cells ◽  
Stem Cell Division ◽  
Functional Relevance

Many stem cells, including Drosophila germline stem cells (GSCs), divide asymmetrically, producing one stem cell and one differentiating daughter. Cytokinesis is often asymmetric, in that only one daughter cell inherits the midbody ring (MR) upon completion of abscission even in apparently symmetrically dividing cells. However, whether the asymmetry in cytokinesis correlates with cell fate or has functional relevance has been poorly explored. Here we show that the MR is asymmetrically segregated during GSC divisions in a centrosome age–dependent manner: male GSCs, which inherit the mother centrosome, exclude the MR, whereas female GSCs, which we here show inherit the daughter centrosome, inherit the MR. We further show that stem cell identity correlates with the mode of MR inheritance. Together our data suggest that the MR does not inherently dictate stem cell identity, although its stereotypical inheritance is under the control of stemness and potentially provides a platform for asymmetric segregation of certain factors.

piwi encodes a nucleoplasmic factor whose activity modulates the number and division rate of germline stem cells

Development ◽  
2000 ◽  
Vol 127 (3) ◽  
pp. 503-514 ◽  
Author(s):  
D.N. Cox ◽  
A. Chao ◽  
H. Lin
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Division ◽  
Germline Stem Cell ◽  
Dual Function ◽  
Germline Stem Cells ◽  
Division Rate ◽  
Germline Expression ◽  
A Cell ◽  
Stem Cell Division

piwi represents the first class of genes known to be required for stem cell self-renewal in diverse organisms. In the Drosophila ovary, piwi is required in somatic signaling cells to maintain germline stem cells. Here we show that piwi encodes a novel nucleoplasmic protein present in both somatic and germline cells, with the highly conserved C-terminal region essential for its function. Removing PIWI protein from single germline stem cells significantly decreases the rate of their division. This suggests that PIWI has a second role as a cell-autonomous promoter of germline stem cell division. Consistent with its dual function, over-expression of piwi in somatic cells causes an increase both in the number of germline stem cells and the rate of their division. Thus, PIWI is a key regulator of stem cell division - its somatic expression modulates the number of germline stem cells and the rate of their division, while its germline expression also contributes to promoting stem cell division in a cell-autonomous manner.

Functions of promyelocytic leukaemia zinc finger (Plzf) in male germline stem cell development and differentiation

2019 ◽  
Vol 31 (8) ◽  
pp. 1315 ◽  
Author(s):  
Daguia Zambe John Clotaire ◽  
Yudong Wei ◽  
Xiuwei Yu ◽  
Tamgue Ousman ◽  
Jinlian Hua
Keyword(s):  
Stem Cells ◽  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Development Stage ◽  
Cell Development ◽  
Promyelocytic Leukaemia ◽  
Germline Stem Cell ◽  
Germline Stem Cells ◽  
Male Germline ◽  
Finger Protein

Promyelocytic leukaemia zinc finger (Plzf), also known as zinc finger and BTB domain containing 16 (ZBTB16) or zinc-finger protein 145 (ZFP145), is a critical zinc finger protein of male germline stem cells (mGSCs). Multiple lines of evidence indicate that Plzf has a central role in the development, differentiation and maintenance of many stem cells, including mGSCs, and Plzf has been validated as an essential transcription factor for mammalian testis development and spermatogenesis. This review summarises current literature focusing on the significance of Plzf in maintaining and regulating self-renewal and differentiation of mGSCs, especially goat mGSCs. The review summarises evidence of the specificity of Plzf expression in germ cell development stage, the known functions of Plzf and the microRNA-mediated mechanisms that control Plzf expression in mGSCs.

scholarly journals Klp10A, a stem cell centrosome-enriched kinesin, balances asymmetries in Drosophila male germline stem cell division

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Cuie Chen ◽  
Mayu Inaba ◽  
Zsolt G Venkei ◽  
Yukiko M Yamashita
Keyword(s):  
Stem Cell ◽  
Cell Division ◽  
Cell Fate ◽  
Germline Stem Cell ◽  
Germline Stem Cells ◽  
Male Germline ◽  
Mother And Daughter ◽  
Stem Cell Divisions ◽  
Stem Cell Division ◽  
Male Germline Stem Cells

Asymmetric stem cell division is often accompanied by stereotypical inheritance of the mother and daughter centrosomes. However, it remains unknown whether and how stem cell centrosomes are uniquely regulated and how this regulation may contribute to stem cell fate. Here we identify Klp10A, a microtubule-depolymerizing kinesin of the kinesin-13 family, as the first protein enriched in the stem cell centrosome in Drosophila male germline stem cells (GSCs). Depletion of klp10A results in abnormal elongation of the mother centrosomes in GSCs, suggesting the existence of a stem cell-specific centrosome regulation program. Concomitant with mother centrosome elongation, GSCs form asymmetric spindle, wherein the elongated mother centrosome organizes considerably larger half spindle than the other. This leads to asymmetric cell size, yielding a smaller differentiating daughter cell. We propose that klp10A functions to counteract undesirable asymmetries that may result as a by-product of achieving asymmetries essential for successful stem cell divisions.

scholarly journals Loss of foxo rescues stem cell aging in Drosophila germ line

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Filippo Artoni ◽  
Rebecca E Kreipke ◽  
Ondina Palmeira ◽  
Connor Dixon ◽  
Zachary Goldberg ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Ionizing Radiation ◽  
Cell Injury ◽  
Germ Line ◽  
Adult Stem Cell ◽  
Cell Aging ◽  
Germline Stem Cells ◽  
Cell Cycle Reentry

Aging stem cells lose the capacity to properly respond to injury and regenerate their residing tissues. Here, we utilized the ability of Drosophila melanogaster germline stem cells (GSCs) to survive exposure to low doses of ionizing radiation (IR) as a model of adult stem cell injury and identified a regeneration defect in aging GSCs: while aging GSCs survive exposure to IR, they fail to reenter the cell cycle and regenerate the germline in a timely manner. Mechanistically, we identify foxo and mTOR homologue, Tor as important regulators of GSC quiescence following exposure to ionizing radiation. foxo is required for entry in quiescence, while Tor is essential for cell cycle reentry. Importantly, we further show that the lack of regeneration in aging germ line stem cells after IR can be rescued by loss of foxo.

Drosophila Mitochondrial Genetics: Evolution of Heteroplasmy Through Germ Line Cell Divisions

Genetics ◽  
1987 ◽  
Vol 117 (4) ◽  
pp. 687-696 ◽  
Author(s):  
Michel Solignac ◽  
Jean Génermont ◽  
Monique Monnerot ◽  
Jean-Claude Mounolou
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Germ Line ◽  
Female Offspring ◽  
Mitochondrial Genetics ◽  
Germ Line Cell ◽  
Cell Divisions ◽  
Drosophila Mauritiana ◽  
Mitochondrial Genotype ◽  
Stem Cell Division

ABSTRACT The mitochondrial genotype of all F1 female offspring (426 individuals) of a single Drosophila mauritiana female, heteroplasmic for two types of mtDNA (a short and a long genome), was established. All descendants were heteroplasmic. The earliest eggs laid by this female show the cytoplasmic genetic structure of ovariole stem cells at the end of development. Cohorts of females from the eggs laid day after day by this female, throughout the 31 days of its life, provide information on the evolution of the mitochondrial genotypes in the course of successive divisions of stem cells. An increase of the percentage of long DNA in offspring was observed as the female aged. Moreover, the variance of the genotypes increases as rounds of stem cell division progress. These results are supported by observations based on the adults issued from the early and late eggs, for three additional heteroplasmic females.

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