Characterization of histone inheritance patterns in the Drosophila female germline

ABSTRACTStem 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 produced from 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 combined histone labeling with DNA Oligopaints to distinguish old versus new histone distribution and visualize their inheritance patterns at single-gene resolution in asymmetrically dividing cells in vivo. This strategy can be widely applied to other biological contexts involving cell fate establishment during development or tissue homeostasis in multicellular organisms.

Download Full-text

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

Molecular Biology of the Cell ◽

10.1091/mbc.e13-09-0541 ◽

2014 ◽

Vol 25 (2) ◽

pp. 267-275 ◽

Cited By ~ 71

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.

Download Full-text

Differential condensation of sister chromatids coordinates with Cdc6 to ensure distinct cell cycle progression inDrosophilamale germline stem cell lineage

10.1101/2021.03.08.434490 ◽

2021 ◽

Author(s):

Rajesh Ranjan ◽

Jonathan Snedeker ◽

Matthew Wooten ◽

Carolina Chu ◽

Sabrina Bracero ◽

...

Keyword(s):

Cell Cycle ◽

Stem Cells ◽

Stem Cell ◽

Cell Cycle Progression ◽

Daughter Cell ◽

Asymmetric Division ◽

Germline Stem Cell ◽

Cycle Progression ◽

Daughter Cells ◽

Sister Chromatids

AbstractStem cells undergo asymmetric division to produce both a self-renewing stem cell and a differentiating daughter cell. DuringDrosophilamale germline stem cell (GSC) asymmetric division, preexisting old histones H3 and H4 are enriched in the self-renewed stem daughter cell, whereas the newly synthesized H3 and H4 are enriched in the differentiating daughter cell. However, the biological consequences in the two daughter cells resulting from asymmetric histone inheritance remained to be elucidated. In this work, we track both old and new histones throughout GSC cell cycle using high spatial and temporal resolution microscopy. We find several unique features differentiating old versus new histone-enriched sister chromatids, including nucleosome density, chromosomal condensation, and H3 Ser10 phosphorylation. These distinct chromosomal features lead to their differential association with Cdc6, an essential component of the pre-replication complex, which subsequently contributes to asynchronous initiation of DNA replication in the two resulting daughter cells. Disruption of asymmetric histone inheritance abolishes both differential Cdc6 association and asynchronous S-phase entry, demonstrating that asymmetric histone acts upstream of these critical events during cell cycle progression. Furthermore, GSC defects are detected under these conditions, indicating a connection between histone inheritance, cell cycle progression and cell fate decision. Together, these studies reveal that cell cycle remodeling as a crucial biological ‘readout’ of asymmetric histone inheritance, which precedes and could lead to other well-known readouts such as differential gene expression. This work also enhances our understanding of asymmetric histone inheritance and epigenetic regulation in other stem cells or asymmetrically dividing cells in multicellular organisms.

Download Full-text

Asymmetry and Cell Fate in Stem Cells and Cancer

Blood ◽

10.1182/blood.v124.21.sci-45.sci-45 ◽

2014 ◽

Vol 124 (21) ◽

pp. SCI-45-SCI-45

Author(s):

Tannishtha Reya

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Cell Fate ◽

Imaging System ◽

Conflicts Of Interest ◽

Asymmetric Division ◽

Hematologic Malignancies ◽

Cell Fate Determinant ◽

In Vivo Imaging System

Abstract Our research focuses on the signals that control stem cell self-renewal and how these signals are hijacked in cancer. Using genetic models, we have shown that classic developmental signaling pathways such as Wnt and Hedgehog play key roles in stem cell growth and regeneration and are dysregulated during leukemia development. In addition, we have used real-time imaging strategies to show that stem cells have the capacity to undergo both symmetric and asymmetric division, and that shifts in the balance between these modes of division are controlled by the microenvironment and subverted by oncogenes. This work led to the discovery that regulators of asymmetric division, such as the cell fate determinant Musashi, can promote aggressive leukemias and may serve as critical targets for diagnostics and therapy in hematologic malignancies. Most recently, we have developed a high resolution in vivo imaging system that has allowed us to begin to map the behavior and interactions of stem cells with the microenvironment within living animals and to define how these change during cancer formation. Disclosures No relevant conflicts of interest to declare.

Download Full-text

Stem cell mitotic drive ensures asymmetric epigenetic inheritance

10.1101/416446 ◽

2018 ◽

Author(s):

Rajesh Ranjan ◽

Jonathan Snedeker ◽

Xin Chen

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Cell Division ◽

Sister Chromatid ◽

Germline Stem Cell ◽

Cell Fates ◽

Daughter Cells ◽

Sister Chromatids ◽

Distinct Cell

SUMMARYThrough the process of symmetric cell division, one mother cell gives rise to two identical daughter cells. Many stem cells utilize asymmetric cell division (ACD) to produce a self-renewed stem cell and a differentiating daughter cell. Since both daughter cells inherit the identical genetic information during ACD, a crucial question concerns how non-genic factors could be inherited differentially to establish distinct cell fates. It has been hypothesized that epigenetic differences at sister centromeres could contribute to biased sister chromatid attachment and segregation. However, direct in vivo evidence has never been shown. Here, we report that a stem cell-specific ‘mitotic drive’ ensures biased sister chromatid attachment and segregation. We have found during stem cell ACD, sister centromeres become asymmetrically enriched with proteins involved in centromere specification and kinetochore function. Furthermore, we show that that temporally asymmetric microtubule activities direct polarized nuclear envelope breakdown, allowing for the preferential recognition and attachment of microtubules to asymmetric sister kinetochores and sister centromeres. This communication occurs in a spatiotemporally regulated manner. Abolishment of either the establishment of asymmetric sister centromeres or the asymmetric microtubule emanation results in randomized sister chromatid segregation, which leads to stem cell loss. Our results demonstrate that the cis-asymmetry at sister centromeres tightly coordinates with the trans-asymmetry from the mitotic machinery to allow for differential attachment and segregation of genetically identical yet epigenetically distinct sister chromatids. Together, these results provide the first direct in vivo mechanisms for partitioning epigenetically distinct sister chromatids in asymmetrically dividing stem cells, which opens a new direction to study how this mechanism could be used in other developmental contexts to achieve distinct cell fates through mitosis.One Sentence SummaryDuring Drosophila male germline stem cell asymmetric division, sister centromeres communicate with spindle microtubules for differential attachment and segregation of sister chromatids.

Download Full-text

Uncoupling of ribosome biogenesis and Tor activation by TRIM-NHL proteins promotes terminal differentiation

10.1101/2021.03.31.437822 ◽

2021 ◽

Author(s):

Jinghua Gui ◽

Felipe Karam Teixeira

Keyword(s):

Protein Synthesis ◽

Stem Cell ◽

Cell Differentiation ◽

Cell Fate ◽

Ribosome Biogenesis ◽

Terminal Differentiation ◽

Stem Cell Differentiation ◽

Cellular Growth ◽

Germline Stem Cell ◽

Female Germline

Proper stem cell differentiation relies on a balance between cellular growth and terminal differentiation, but the mechanisms coordinating these processes remain elusive. Recent studies indicate that ribosome biogenesis (RiBi) and protein synthesis, two of the most energy-consuming cellular processes supporting growth, are tightly regulated and yet can be uncoupled during stem cell fate transitions. Here, using the Drosophila adult female germline stem cell (GSC) and larval neuroblast (NB) systems, we show that Mei-P26 and Brat, two Drosophila TRIM-NHL paralogues of the mammalian TRIM32 protein family, are responsible for uncoupling RiBi and protein synthesis during GSC and NB differentiation, respectively. This is achieved by TRIM-NHL-mediated activation of the Target of rapamycin (Tor) kinase and concomitant repression of RiBi specifically during stem cell differentiation. In consequence, the anabolic reprogramming established by TRIM-NHL activity creates the conditions for terminal differentiation. In agreement with this, depletion of mei-P26 or brat, which results in excessive cellular growth and defective terminal differentiation, can be counterbalanced by ectopic activation of Tor together with suppression of RiBi, allowing completion of differentiation. Our work indicates that TRIM-NHL proteins uncouple RiBi and translation activities to coordinate growth and differentiation, and proposes that the control of cellular resources provides a meter for terminal differentiation.

Download Full-text

Stiffness Gradients Mimicking In Vivo Tissue Variation Regulate Mesenchymal Stem Cell Fate

PLoS ONE ◽

10.1371/journal.pone.0015978 ◽

2011 ◽

Vol 6 (1) ◽

pp. e15978 ◽

Cited By ~ 302

Author(s):

Justin R. Tse ◽

Adam J. Engler

Keyword(s):

Stem Cell ◽

Mesenchymal Stem Cell ◽

Cell Fate ◽

Stem Cell Fate

Download Full-text

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

eLife ◽

10.7554/elife.20977 ◽

2016 ◽

Vol 5 ◽

Cited By ~ 14

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.

Download Full-text

RNAi-based screens uncover a potential new role for the orphan neuropeptide receptor Moody in Drosophila female germline stem cell maintenance

PLoS ONE ◽

10.1371/journal.pone.0243756 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0243756

Author(s):

Tianlu Ma ◽

Shinya Matsuoka ◽

Daniela Drummond-Barbosa

Keyword(s):

Stem Cell ◽

Egg Production ◽

Large Scale ◽

Signal To Noise Ratio ◽

Egg Laying ◽

Melatonin Receptors ◽

Germline Stem Cell ◽

Stem Cell Maintenance ◽

Female Germline ◽

Cell Maintenance

Reproduction is highly sensitive to changes in physiology and the external environment. Neuropeptides are evolutionarily conserved signaling molecules that regulate multiple physiological processes. However, the potential reproductive roles of many neuropeptide signaling pathways remain underexplored. Here, we describe the results of RNAi-based screens in Drosophila melanogaster to identify neuropeptides/neuropeptide receptors with potential roles in oogenesis. The screen read-outs were either the number of eggs laid per female per day over time or fluorescence microscopy analysis of dissected ovaries. We found that the orphan neuropeptide receptor encoded by moody (homologous to mammalian melatonin receptors) is likely required in somatic cells for normal egg production and proper germline stem cell maintenance. However, the egg laying screens had low signal-to-noise ratio and did not lead to the identification of additional candidates. Thus, although egg count assays might be useful for large-scale screens to identify oogenesis regulators that result in dramatic changes in oogenesis, more labor-intensive microscopy-based screen are better applicable for identifying new physiological regulators of oogenesis with more subtle phenotypes.

Download Full-text