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.

scholarly journals Emerging mechanisms of asymmetric stem cell division

2018 ◽  
Vol 217 (11) ◽  
pp. 3785-3795 ◽  
Author(s):  
Zsolt G. Venkei ◽  
Yukiko M. Yamashita
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Division ◽  
Asymmetric Cell Division ◽  
Binary Outcomes ◽  
Cellular Mechanisms ◽  
Asymmetric Cell Divisions ◽  
Cell Divisions ◽  
Dividing Cells ◽  
Stem Cell Division

The asymmetric cell division of stem cells, which produces one stem cell and one differentiating cell, has emerged as a mechanism to balance stem cell self-renewal and differentiation. Elaborate cellular mechanisms that orchestrate the processes required for asymmetric cell divisions are often shared between stem cells and other asymmetrically dividing cells. During asymmetric cell division, cells must establish asymmetry/polarity, which is guided by varying degrees of intrinsic versus extrinsic cues, and use intracellular machineries to divide in a desired orientation in the context of the asymmetry/polarity. Recent studies have expanded our knowledge on the mechanisms of asymmetric cell divisions, revealing the previously unappreciated complexity in setting up the cellular and/or environmental asymmetry, ensuring binary outcomes of the fate determination. In this review, we summarize recent progress in understanding the mechanisms and regulations of asymmetric stem cell division.

scholarly journals Symmetric Inheritance of Histones H3 in Drosophila Male Germline Stem Cell Divisions

2021 ◽  
Author(s):  
Julie Ray ◽  
Keith A. Maggert
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Germ Line ◽  
Germline Stem Cell ◽  
Cell Nuclei ◽  
Cell Divisions ◽  
Regulatory Information ◽  
Alternative Hypotheses ◽  
Stem Cell Divisions ◽  
Gene Regulatory

Mitotically-stable epigenetic memory requires a mechanism for the maintenance of gene-regulatory information through the cell division cycle. Typically DNA-protein contacts are disrupted by DNA replication, but in some cases locus- specific association between DNA and overlying histones may appear to be maintained, providing a plausible mechanism for the transmission of histone-associated gene-regulatory information to daughter cells. Male Drosophila melanogaster testis germ stem cell divisions seem a clear example of such inheritance, as previously chromatin-bound histone H3.2 proteins (presumably with their post-translational modifications intact) have been reported to be retained in the germ stem cell nuclei, while newly synthesized histones are incorporated exclusively into daughter spermatogonial chromosomes. To investigate the rate of errors in this selective partitioning that may lead to defects in the epigenetic identity of germ stem cells, we employed a photoswitchable Dendra2 moiety as a C-terminal fusion on Histones H3; we could thereby discriminate histones translated before photoswitching and those translated after. We found instead that male germ line stem cell divisions show no evidence of asymmetric histone partitioning, even after a single division, and thus no evidence for locus-specific retention of either Histone H3.2 or Histone H3.3. We considered alternative hypotheses for the appearance of asymmetry and find that previous reports of asymmetric histone distribution in male germ stem cells can be satisfactorily explained by asynchrony between subsequent sister stem cell and spermatogonial 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.

Male germ line stem cells: from cell biology to cell therapy

2003 ◽  
Vol 15 (6) ◽  
pp. 323 ◽  
Author(s):  
David Pei-Cheng Lin ◽  
Ming-Yu Chang ◽  
Bo-Yie Chen ◽  
Han-Hsin Chang
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Lines ◽  
Germ Cells ◽  
Germ Line ◽  
Current Status ◽  
Seminiferous Tubules ◽  
Male Germ Line ◽  
Male Germ Cells ◽  
Stem Cell Lines

Research using stem cells has several applications in basic biology and clinical medicine. Recent advances in the establishment of male germ line stem cells provided researchers with the ability to identify, isolate, maintain, expand and differentiate the spermatogonia, the primitive male germ cells, as cell lines under in vitro conditions. The ability to culture and manipulate stem cell lines from male germ cells has gradually facilitated research into spermatogenesis and male infertility, to an extent beyond that facilitated by the use of somatic stem cells. After the introduction of exogenous genes, the spermatogonial cells can be transplanted into the seminiferous tubules of recipients, where the transplanted cells can contribute to the offspring. The present review concentrates on the origin, life cycle and establishment of stem cell lines from male germ cells, as well as the current status of transplantation techniques and the application of spermatogonial stem cell lines.

Generation of Functional Hepatocytes From Mouse Germ Line Cell-Derived Pluripotent Stem Cells In Vitro

2010 ◽  
Vol 19 (8) ◽  
pp. 1183-1194 ◽  
Author(s):  
Sharmila Fagoonee ◽  
Robin M. Hobbs ◽  
Letizia De Chiara ◽  
Daniela Cantarella ◽  
Rosario M. Piro ◽  
...  
Keyword(s):  
Stem Cells ◽  
Pluripotent Stem Cells ◽  
Germ Line ◽  
Germ Line Cell

scholarly journals CENP-C regulates centromere assembly, asymmetry and epigenetic age in Drosophila germline stem cells

2020 ◽  
Author(s):  
Ben L Carty ◽  
Anna A Dattoli ◽  
Elaine M Dunleavy
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Germ Line ◽  
Asymmetric Distribution ◽  
Germline Stem Cells ◽  
Daughter Cells ◽  
Sister Chromatids ◽  
Asymmetric Divisions ◽  
Centromere Assembly

AbstractGermline stem cells divide asymmetrically to produce one new daughter stem cell and one daughter cell that will subsequently undergo meiosis and differentiate to generate the mature gamete. The silent sister hypothesis proposes that in asymmetric divisions, the selective inheritance of sister chromatids carrying specific epigenetic marks between stem and daughter cells impacts cell fate. To facilitate this selective inheritance, the hypothesis specifically proposes that the centromeric region of each sister chromatid is distinct. In Drosophila germ line stem cells (GSCs), it has recently been shown that the centromeric histone CENP-A (called CID in flies) - the epigenetic determinant of centromere identity - is asymmetrically distributed between sister chromatids. In these cells, CID deposition occurs in G2 phase such that sister chromatids destined to end up in the stem cell harbour more CENP-A, assemble more kinetochore proteins and capture more spindle microtubules. These results suggest a potential mechanism of ‘mitotic drive’ that might bias chromosome segregation. Here we report that the inner kinetochore protein CENP-C, is required for the assembly of CID in G2 phase in GSCs. Moreover, CENP-C is required to maintain a normal asymmetric distribution of CID between stem and daughter cells. In addition, we find that CID is lost from centromeres in aged GSCs and that a reduction in CENP-C accelerates this loss. Finally, we show that CENP-C depletion in GSCs disrupts the balance of stem and daughter cells in the ovary, shifting GSCs toward a self-renewal tendency. Ultimately, we provide evidence that centromere assembly and maintenance via CENP-C is required to sustain asymmetric divisions in female Drosophila GSCs.

scholarly journals Planarian stem cells sense the identity of the missing pharynx to launch its targeted regeneration

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Tisha E Bohr ◽  
Divya A Shiroor ◽  
Carolyn E Adler
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Division ◽  
Cell Types ◽  
Erk Signaling ◽  
Stem Cell Population ◽  
Cell Responses ◽  
Stem Cell Division ◽  
Tissue Production ◽  
Single Organ

In order to regenerate tissues successfully, stem cells must detect injuries and restore missing cell types through largely unknown mechanisms. Planarian flatworms have an extensive stem cell population responsible for regenerating any organ after amputation. Here, we compare planarian stem cell responses to different injuries by either amputation of a single organ, the pharynx, or removal of tissues from other organs by decapitation. We find that planarian stem cells adopt distinct behaviors depending on what tissue is missing to target progenitor and tissue production towards missing tissues. Loss of non-pharyngeal tissues only increases non-pharyngeal progenitors, while pharynx removal selectively triggers division and expansion of pharynx progenitors. By pharmacologically inhibiting either mitosis or activation of the MAP kinase ERK, we identify a narrow window of time during which stem cell division and ERK signaling produces pharynx progenitors necessary for regeneration. These results indicate that planarian stem cells can tailor their output to match the regenerative needs of the animal.

429 GENERATION OF Oct4-EGFP TRANSGENIC PIGS FOR MONITORING REPROGRAMMING AND PLURIPOTENCY

2010 ◽  
Vol 22 (1) ◽  
pp. 371 ◽  
Author(s):  
M. Nowak-Imialek ◽  
W. A. Kues ◽  
B. Petersen ◽  
A. Lucas-Hahn ◽  
D. Herrmann ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Embryonic Stem Cells ◽  
Fluorescent Protein ◽  
Germ Line ◽  
Embryonic Stem ◽  
Large Animal Model ◽  
Large Animal ◽  
Transgenic Pigs ◽  
Egfp Fluorescence

The Oct4 gene is an essential transcription factor for maintenance of pluripotency in mammals. Here, we report the production of cloned transgenic pigs carrying a genomic construct encompassing murine Oct4 regulatory regions and driving an enhanced green fluorescent protein (Oct4-EGFP) construct. We employed fetal porcine fibroblasts, stably co-transfected with neomycin and the mouse Oct4-EGFP construct, for somatic cell nuclear transfer to reconstruct transgenic embryos. The cloned embryos (811 embryos) were surgically transferred into the oviducts of 8 recipient animals. Two pregnancies were terminated at Day 25 for recovery of fetuses and the others delivered a total of 23 piglets, of which 11 survived the postpartum period. A detailed analysis showed that the Oct4-EGFP construct was active in cloned pig blastocysts from Days 5 to 6. EGFP fluorescence was found exclusively in the primordial germ cells of Day 25 fetuses, whereas somatic tissues did not express the transgene. We could also detect expression of Oct4-EGFP in individual cells of the postnatal testis. Testis-specific expression was confirmed by Northern blotting. We fused transgenic porcine fibroblasts with murine embryonic stem cells to analyze reactivation of the Oct4-EGFP transgene under experimental reprogramming conditions. The fused hybrids displayed stem cell morphology and a high proliferation rate and started to express EGFP fluorescence 72 h after fusion. In conclusion, we report the production of viable Oct4-EGFP transgenic piglets that express EGFP exclusively in germ line and pluripotent cells. This transgenic pig line is a valuable tool for derivation and maintenance of porcine embryonic stem cells and will be of utmost interest for reprogramming studies and for preclinical testing of stem cell therapies in a large animal model. Funded by BMBF.

scholarly journals Regulating the regulator: Numb acts upstream of p53 to control mammary stem and progenitor cell

2015 ◽  
Vol 211 (4) ◽  
pp. 737-739 ◽  
Author(s):  
Marisa M. Faraldo ◽  
Marina A. Glukhova
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Cell Expansion ◽  
Progenitor Cell ◽  
Asymmetric Cell Divisions ◽  
Stem Cell Expansion ◽  
Cell Divisions ◽  
Cell Fate Determinant ◽  
Mammary Stem

In this issue, Tosoni et al. (2015. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201505037) report that cell fate determinant and tumor suppressor Numb imposes asymmetric cell divisions in mammary stem cells by regulating p53. Numb thereby restricts mammary stem cell expansion and controls the proliferation and lineage-specific characteristics of their progeny.

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