scholarly journals Live imaging of the Drosophila ovarian niche shows spectrosome and centrosome dynamics during asymmetric germline stem cell division

Development ◽  
2021 ◽  
Author(s):  
Gema Villa-Fombuena ◽  
María Lobo-Pecellín ◽  
Miriam Marín-Menguiano ◽  
Patricia Rojas-Ríos ◽  
Acaimo González-Reyes
Keyword(s):  
Stem Cell ◽  
Mitotic Spindle ◽  
Cell Lineage ◽  
Intrinsic Property ◽  
Live Imaging ◽  
Cycle Phase ◽  
Cell Cortex ◽  
Germline Stem Cell ◽  
Germline Stem Cells ◽  
Centriole Duplication

Drosophila female germline stem cells (GSCs) are found inside the cellular niche at the tip of the ovary. They undergo asymmetric divisions to renew the stem cell lineage and to produce sibling cystoblasts that will in turn enter differentiation. GSCs and cystoblasts contain spectrosomes, membranous structures essential to orientate the mitotic spindle and that, particularly in GSCs, change shape depending on the cell cycle phase. Using live imaging and a GFP fusion of the spectrosome component Par-1, we follow the complete spectrosome cycle throughout GSC division and quantify the relative duration of the different spectrosome shapes. We also determine that the Par-1 kinase shuttles between the spectrosome and the cytoplasm during mitosis and observe the continuous addition of new material to the GSC and cystoblast spectrosomes. Next, we utilise the Fly-FUCCI tool to define in live and fixed tissues that GSCs have a shorter G1 compared to the G2 phase. The observation of centrosomes in dividing GSCs allowed us to determine that centrosomes separate very early in G1, prior to centriole duplication. Furthermore, we show that the anterior centrosome associates with the spectrosome only during mitosis and that, upon mitotic spindle assembly, it translocates to the cell cortex, where it remains anchored until centrosome separation. Finally, we demonstrate that the asymmetric division of GSCs is not an intrinsic property of these cells, since the spectrosome of GSC-like cells located outside of the niche can divide symmetrically. Thus, GSCs display unique properties during division, a behaviour influenced by the surrounding niche.

scholarly journals Notch signaling is required for survival of the germline stem cell lineage in testes of Drosophila melanogaster

2019 ◽  
Author(s):  
Chun L. Ng ◽  
Qian Yue ◽  
Schulz Cordula
Keyword(s):  
Drosophila Melanogaster ◽  
Stem Cell ◽  
Notch Signaling ◽  
Transition Zone ◽  
Cell Lineage ◽  
Germline Stem Cell ◽  
Germline Stem Cells ◽  
Stem Cell Lineage ◽  
Cyst Cells ◽  
Germline Cells

AbstractIn all metazoan species, sperm is produced from germline stem cells. These self-renew and produce daughter cells that amplify and differentiate dependent on interactions with somatic support cells. In the male gonad of Drosophila melanogaster, the germline and somatic cyst cells co-differentiate as cysts, an arrangement in which the germline is completely enclosed by cytoplasmic extensions from the cyst cells. Notch is a developmentally relevant receptor in a pathway requiring immediate proximity with the signal sending cell. Here, we show that Notch is expressed in the cyst cells of wild-type testes. Notch becomes activated in the transition zone, an apical area of the testes in which the cyst cells express stage-specific transcription factors and the enclosed germline finalizes transit-amplifying divisions. Reducing the ligand Delta from the germline cells via RNA-Interference or reducing the receptor Notch from the cyst cells via CRISPR resulted in cell death concomitant with loss of germline cells from the transition zone. This shows that Notch signaling is essential for the survival of the germline stem cell lineage.

scholarly journals Three RNA Binding Proteins Form a Complex to Promote Differentiation of Germline Stem Cell Lineage in Drosophila

PLoS Genetics ◽  
2014 ◽  
Vol 10 (11) ◽  
pp. e1004797 ◽  
Author(s):  
Di Chen ◽  
Chan Wu ◽  
Shaowei Zhao ◽  
Qing Geng ◽  
Yu Gao ◽  
...  
Keyword(s):  
Stem Cell ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Cell Lineage ◽  
Germline Stem Cell ◽  
Stem Cell Lineage

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 An improved organ explant culture method reveals stem cell lineage dynamics in the adult Drosophila intestine

2021 ◽  
Author(s):  
Marco Marchetti ◽  
Chenge Zhang ◽  
Bruce A Edgar
Keyword(s):  
Stem Cell ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Cell Lineage ◽  
Live Imaging ◽  
Explant Culture ◽  
Renal Tubules ◽  
Culture Techniques ◽  
Tissue Organization ◽  
Culture Protocol

In recent years, live-imaging techniques have been developed for the adult midgut of Drosophila melanogaster that allow temporal characterization of key processes involved in stem cell and tissue homeostasis. However, current organ culture techniques are limited to imaging sessions of <16 hours, an interval too short to track dynamic processes such as damage responses and regeneration, which can unfold over several days. Therefore, we developed a new organ explant culture protocol capable of sustaining midguts ex vivo for up to 3 days. This was made possible by the formulation of a culture medium specifically designed for adult Drosophila tissues with an increased Na+/K+ ratio and trehalose concentration, and by placing midguts at an air-liquid interface for enhanced oxygenation. We show that midgut progenitor cells can respond to gut epithelium damage ex vivo, proliferating and differentiating to replace lost cells, but are quiescent in healthy intestines. Using ex vivo gene induction to promote stem cell proliferation, we demonstrate that intestinal stem lineages can be traced through multiple cell divisions using live imaging. Both asymmetric and symmetric divisions can be identified in the reconstructed lineages. We find that daughter cells of asymmetric divisions remain in close proximity of each other, while the progeny of symmetric divisions actively move apart, with implications for cell differentiation and tissue organization. We show that the same culture set-up is useful for imaging adult renal tubules and ovaries for up to 72 hours. By enabling both long-term imaging and real-time ex vivo gene manipulation, our simple culture protocol provides a powerful tool for studies of epithelial biology and cell lineage behavior.

Nanos and Pumilio have critical roles in the development and function of Drosophila germline stem cells

Development ◽  
1998 ◽  
Vol 125 (4) ◽  
pp. 679-690 ◽  
Author(s):  
A. Forbes ◽  
R. Lehmann
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Germ Cells ◽  
Rna Binding ◽  
Drosophila Embryo ◽  
Germline Stem Cell ◽  
Germline Stem Cells ◽  
Embryonic Patterning ◽  
Germline Development ◽  
Egg Chambers

The zinc-finger protein Nanos and the RNA-binding protein Pumilio act together to repress the translation of maternal hunchback RNA in the posterior of the Drosophila embryo, thereby allowing abdomen formation. nanos RNA is localized to the posterior pole during oogenesis and the posteriorly synthesized Nanos protein is sequestered into the germ cells as they form in the embryo. This maternally provided Nanos protein is present in germ cells throughout embryogenesis. Here we show that maternally deposited Nanos protein is essential for germ cell migration. Lack of zygotic activity of nanos and pumilio has a dramatic effect on germline development of homozygous females. Given the coordinate function of nanos and pumilio in embryonic patterning, we analyzed the role of these genes in oogenesis. We find that both genes act in the germline. Although the nanos and pumilio ovarian phenotypes have similarities and both genes ultimately affect germline stem cell development, the focus of these phenotypes appears to be different. While pumilio mutant ovaries fail to maintain stem cells and all germline cells differentiate into egg chambers, the focus of nanos function seems to lie in the differentiation of the stem cell progeny, the cystoblast. Consistent with the model that nanos and pumilio have different phenotypic foci during oogenesis, we detect high levels of Pumilio protein in the germline stem cells and high levels of Nanos in the dividing cystoblasts. We therefore suggest that, in contrast to embryonic patterning, Nanos and Pumilio may interact with different partners in the germline.

scholarly journals JNK signaling triggers spermatogonial dedifferentiation during chronic stress to maintain the germline stem cell pool in the Drosophila testis

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Salvador C Herrera ◽  
Erika A Bach
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Chronic Stress ◽  
Germline Stem Cell ◽  
Germline Stem Cells ◽  
Jnk Signaling ◽  
Cell Pool ◽  
Drosophila Testis ◽  
Bag Of Marbles ◽  
Stem Cell Pool

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.

Somatic control over the germline stem cell lineage during Drosophila spermatogenesis

Nature ◽  
2000 ◽  
Vol 407 (6805) ◽  
pp. 754-757 ◽  
Author(s):  
John Tran ◽  
Tamara J. Brenner ◽  
Stephen DiNardo
Keyword(s):  
Stem Cell ◽  
Cell Lineage ◽  
Germline Stem Cell ◽  
Stem Cell Lineage
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