scholarly journals Cell Cycle Kinetics and Development of Hydra Attenuata

1974 ◽  
Vol 16 (2) ◽  
pp. 359-375 ◽  
Author(s):  
C. N. DAVID ◽  
A. GIERER
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Interstitial Cell ◽  
Flow Model ◽  
Interstitial Cells ◽  
Nerve Cells ◽  
Stem Cell Divisions ◽  
Basal Disk ◽  
Hydra Attenuata

The differentiation of nerve cells and nematocytes in Hydra attenuata has been investigated by labelling interstitial cell precursors with [3H]thymidine and following by autoradiography the appearance of labelled, newly differentiated cells. Nematocyte differentiation occurs only in the gastric region where labelled nematoblasts appear 12 h and labelled nematocytes 72-96 h after addition of [3H]thymidine. Labelled nerves appear in hypostome, gastric region, and basal disk about 18 h after addition of [3H]thymidine. The lag in the appearance of labelled cells includes cell division of the precursor as well as differentiation since nerves and nematocytes have 2n postmitotic nuclear DNA content. A cell flow model is proposed for interstitial cells and their differentiated products. Stem cells occur as single interstitial cells or in pairs. Per cell generation about 60 % of the daughter cells of stem cell divisions remain stem cells and about 40 % differentiate nerves and nematocytes. Nerves differentiate directly from stem cells in about 1 day. Nematocyte differentiation requires 5-7 days including proliferation of a cluster of 4, 8, 16 or 32 interstitial cells and differentiation of a nematocyst capsule in each cell. The numbers of interstitial cells and nematoblasts predicted by the cell flow model from the rates of nerve differentiation (900 nerves/day/ hydra), nematocyte differentiation (1760 nematocyte nests/day/hydra) and stem cell proliferation (stem cell cycle = 24 h), agree with the numbers of these cells observed in hydra. The number of stem cells per hydra is 3000-6000 depending on assumptions about the time of determination. The ratio of nematocyte to nerve differentiation averaged over the whole hydra is 3:1. In the hypostome and basal disk interstitial cell differentiation occurs exclusively to nerve cells while in the gastric region the ratio of nematocyte to nerve differentiation is about 7:1.

scholarly journals Reoccurring neural stem cell divisions in the adult zebrafish telencephalon are sufficient for the emergence of aggregated spatiotemporal patterns

PLoS Biology ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. e3000708
Author(s):  
Valerio Lupperger ◽  
Carsten Marr ◽  
Prisca Chapouton
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Neural Stem Cell ◽  
Agent Based ◽  
Brain Hemispheres ◽  
Random Fashion ◽  
Dividing Cells ◽  
Stem Cell Divisions ◽  
Stem Cell Populations

Regulation of quiescence and cell cycle entry is pivotal for the maintenance of stem cell populations. Regulatory mechanisms, however, are poorly understood. In particular, it is unclear how the activity of single stem cells is coordinated within the population or if cells divide in a purely random fashion. We addressed this issue by analyzing division events in an adult neural stem cell (NSC) population of the zebrafish telencephalon. Spatial statistics and mathematical modeling of over 80,000 NSCs in 36 brain hemispheres revealed weakly aggregated, nonrandom division patterns in space and time. Analyzing divisions at 2 time points allowed us to infer cell cycle and S-phase lengths computationally. Interestingly, we observed rapid cell cycle reentries in roughly 15% of newly born NSCs. In agent-based simulations of NSC populations, this redividing activity sufficed to induce aggregated spatiotemporal division patterns that matched the ones observed experimentally. In contrast, omitting redivisions leads to a random spatiotemporal distribution of dividing cells. Spatiotemporal aggregation of dividing stem cells can thus emerge solely from the cells’ history.

scholarly journals Elimination by Hydra interstitial and nerve cells by means of colchicine

1976 ◽  
Vol 21 (1) ◽  
pp. 1-13 ◽  
Author(s):  
R.D. Campbell
Keyword(s):  
Stem Cell ◽  
Epithelial Cells ◽  
Effective Treatment ◽  
Interstitial Cells ◽  
Nerve Cells ◽  
Digestive Cells ◽  
Hydra Attenuata ◽  
Derivatives Of

Hydra treated with colchicine or Colcemid become depleted of 95–99% of their interstitial cells and derivatives of this stem cell: nematoblasts, nematocytes and nerve cells. A second treatment removes most or all remaining interstitial cells. The most effective treatment is an 8-h immersion of whole Hydra attenuata in 0.04% Colcemid or 0.4% colchicine. Interstitial cells are eliminated through phagocytosis by both ectodermal and endodermal epithelial cells. The endodermal digestive cells send processes through the mesoglea which engulf interstitial cells and retract them into the endoderm. The resultant hydra, though devoid of nematocysts, can be artificially fed: these animals grow and bud and can be used to study the behaviour and development of tissue lacking nerve and interstitial cells.

scholarly journals Regulation of interstitial cell differentiation in Hydra attenuata. IV. Nerve cell commitment in head regeneration is position-dependent

1978 ◽  
Vol 34 (1) ◽  
pp. 27-38
Author(s):  
M.S. Yaross ◽  
H.R. Bode
Keyword(s):  
Stem Cell ◽  
Cell Differentiation ◽  
Nerve Cell ◽  
Interstitial Cell ◽  
Fold Increase ◽  
Nerve Cells ◽  
Multipotent Stem Cell ◽  
Hydra Attenuata ◽  
Cell Commitment ◽  
Head Regeneration

In hydra, nerve cells are a differentiation product of the interstitial cell, a multipotent stem cell. Nerve cell commitment was examined during head regeneration in Hydra attenuata. Within 3 h of head removal there is a 10- to 20-fold increase in nerve cell commitment in the tissue which subsequently forms the new head. Nerve cell commitment is unaltered in the remainder of the gastric region. This local increase in nerve cell commitment is responsible for about one half the new nerve cells formed during head regeneration, while one half differentiate from interstitial cells that migrate into the regenerating tip.

scholarly journals Cell cycle lengths of stem cells and their lineage from cellular demography

2020 ◽  
Author(s):  
Purna Gadre ◽  
Nitin Nitsure ◽  
Debasmita Mazumdar ◽  
Samir Gupta ◽  
Krishanu Ray
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Fold Increase ◽  
Tissue Homeostasis ◽  
Fine Tuning ◽  
List Type ◽  
Germline Stem Cells ◽  
Stem Cell Divisions ◽  
Cycle Lengths

AbstractAdult stem cells and their transit-amplifying (TA) progeny dynamically alter their proliferation rates to maintain tissue homeostasis. To test how the division rates of stem cell and TA cells affect tissue growth and differentiation, we developed a computation strategy which estimates the average cell cycle lengths/lifespans of germline stem cells (GSCs) and their TA progeny from cellular demography. Analysis of the wild-type data from Drosophila testis using this method indicated anomalous changes in lifespans during the germline transit-amplification with a nearly 1.3-fold increase after the first division and about a 2-fold decrease in the subsequent stage. Genetic perturbations altering the cell cycle rates of GSC and its immediate daughter, the gonialblast (GB), proportionately changed the rates of subsequent TA divisions. Notably, a nearly 2-fold increase or decrease in the total TA duration did not alter the induction of meiosis after four mitotic cycles. Altogether, these results suggest that the rates of GSC and GB divisions can adjust the rates of subsequent divisions and the onset of differentiation.Significance StatementDynamic regulation of the proliferation rate of stem cells and their transit-amplifying daughters maintains tissue homeostasis in different conditions such as tissue regeneration, aging, and hormonal imbalance. Previous studies suggested that a molecular clock in the stem cell progeny determines the timing of differentiation. This work shows that alterations of the rates of stem cell divisions, as well as that of its progeny, could override the differentiation clock in the Drosophila testis, and highlights a possible mechanism of fine-tuning the transit-amplification program under different conditions such as tissue damage, aging, and hormonal inputs. Also, the method developed for this study could be adapted to estimate lineage expansion plasticity from demographic changes in other systems.HighlightsDetermination of cellular lifespan during transit-amplification from demographyLifespans of Drosophila male germline cells changes anomalously during the TALifespan changes of germline stem cells readjust that of the progeny cellsAnomalous lifespan expansion midway through TA precedes the Bam onset

scholarly journals Bmi1 Augments Proliferation and Survival of Cortical Bone-Derived Stem Cells after Injury through Novel Epigenetic Signaling via Histone 3 Regulation

2021 ◽  
Vol 22 (15) ◽  
pp. 7813
Author(s):  
Lindsay Kraus ◽  
Chris Bryan ◽  
Marcus Wagner ◽  
Tabito Kino ◽  
Melissa Gunchenko ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Dna Damage ◽  
Stem Cell ◽  
Histone Modification ◽  
Epigenetic Regulation ◽  
Critical Role ◽  
Proliferative Potential ◽  
Therapeutic Effects ◽  
Histone 3

Ischemic heart disease can lead to myocardial infarction (MI), a major cause of morbidity and mortality worldwide. Multiple stem cell types have been safely transferred into failing human hearts, but the overall clinical cardiovascular benefits have been modest. Therefore, there is a dire need to understand the basic biology of stem cells to enhance therapeutic effects. Bmi1 is part of the polycomb repressive complex 1 (PRC1) that is involved in different processes including proliferation, survival and differentiation of stem cells. We isolated cortical bones stem cells (CBSCs) from bone stroma, and they express significantly high levels of Bmi1 compared to mesenchymal stem cells (MSCs) and cardiac-derived stem cells (CDCs). Using lentiviral transduction, Bmi1 was knocked down in the CBSCs to determine the effect of loss of Bmi1 on proliferation and survival potential with or without Bmi1 in CBSCs. Our data show that with the loss of Bmi1, there is a decrease in CBSC ability to proliferate and survive during stress. This loss of functionality is attributed to changes in histone modification, specifically histone 3 lysine 27 (H3K27). Without the proper epigenetic regulation, due to the loss of the polycomb protein in CBSCs, there is a significant decrease in cell cycle proteins, including Cyclin B, E2F, and WEE as well as an increase in DNA damage genes, including ataxia-telangiectasia mutated (ATM) and ATM and Rad3-related (ATR). In conclusion, in the absence of Bmi1, CBSCs lose their proliferative potential, have increased DNA damage and apoptosis, and more cell cycle arrest due to changes in epigenetic modifications. Consequently, Bmi1 plays a critical role in stem cell proliferation and survival through cell cycle regulation, specifically in the CBSCs. This regulation is associated with the histone modification and regulation of Bmi1, therefore indicating a novel mechanism of Bmi1 and the epigenetic regulation of stem cells.

scholarly journals Quiescent, Slow-Cycling Stem Cell Populations in Cancer: A Review of the Evidence and Discussion of Significance

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Nathan Moore ◽  
Stephen Lyle
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Cancer Stem Cells ◽  
Adult Stem Cells ◽  
Cell Populations ◽  
Proliferative Potential ◽  
Cell Cycle Regulators ◽  
Slow Cycling ◽  
Stem Cell Populations

Long-lived cancer stem cells (CSCs) with indefinite proliferative potential have been identified in multiple epithelial cancer types. These cells are likely derived from transformed adult stem cells and are thought to share many characteristics with their parental population, including a quiescent slow-cycling phenotype. Various label-retaining techniques have been used to identify normal slow cycling adult stem cell populations and offer a unique methodology to functionally identify and isolate cancer stem cells. The quiescent nature of CSCs represents an inherent mechanism that at least partially explains chemotherapy resistance and recurrence in posttherapy cancer patients. Isolating and understanding the cell cycle regulatory mechanisms of quiescent cancer cells will be a key component to creation of future therapies that better target CSCs and totally eradicate tumors. Here we review the evidence for quiescent CSC populations and explore potential cell cycle regulators that may serve as future targets for elimination of these cells.

Genetic analysis of developmental mechanisms in hydra. V. Cell lineage and development of chimera hydra

1978 ◽  
Vol 32 (1) ◽  
pp. 215-232
Author(s):  
T. Sugiyama ◽  
T. Fujisawa
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Interstitial Cell ◽  
Cell Lineage ◽  
Interstitial Cells ◽  
Nerve Cells ◽  
Polyp Size ◽  
Primary Determinant ◽  
One Year ◽  
Almost All

Chimeric hydra were produced by making use of a strain (nf-1) which lacks interstitial cells, nerve cells and nematocytes. This strain arises by spontaneous loss of interstitial cells from its parental strain (sf-1) (Sugiyama & Fujisawa, 1978). Reintroduction of interstitial cells from other strains into nf-1 leads to the creation of chimeric strains that consisted of epithelial cells derived from strain sf-1 and interstitial cells and their derivatives (nerves and nematocytes) from other strains. In chimeras, interstitial or epithelial cells apparently maintain very stable cell lineages; no indication was obtained that suggested interstitial cell differentiation into epithelial cells or dedifferentiation in the opposite direction during the long courses of chimera cultures (up to one year). Developmental characters of chimeras were examined and compared to those of the epithelial cell (sf-1) and the interstitial cell donors. Almost all of the chimera's characters examined (growth rate, budding rate, tentacle numbers, polyp size, regenerative capacity, etc.) closely resembled those of the epithelial cell donor, but not of the interstitial cell donors. This suggests that epithelial cells, rather than interstitial or nerve cells, are the primary determinant of most, if not all, of hydra developmental characters.

scholarly journals APC is required for muscle stem cell proliferation and skeletal muscle tissue repair

2015 ◽  
Vol 210 (5) ◽  
pp. 717-726 ◽  
Author(s):  
Alice Parisi ◽  
Floriane Lacour ◽  
Lorenzo Giordani ◽  
Sabine Colnot ◽  
Pascal Maire ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Skeletal Muscle ◽  
Stem Cells ◽  
Stem Cell ◽  
Cell Cycle Progression ◽  
Cell Types ◽  
Double Knockout ◽  
Muscle Stem Cells ◽  
Adult Muscle ◽  
Canonical Wnt

The tumor suppressor adenomatous polyposis coli (APC) is a crucial regulator of many stem cell types. In constantly cycling stem cells of fast turnover tissues, APC loss results in the constitutive activation of a Wnt target gene program that massively increases proliferation and leads to malignant transformation. However, APC function in skeletal muscle, a tissue with a low turnover rate, has never been investigated. Here we show that conditional genetic disruption of APC in adult muscle stem cells results in the abrogation of adult muscle regenerative potential. We demonstrate that APC removal in adult muscle stem cells abolishes cell cycle entry and leads to cell death. By using double knockout strategies, we further prove that this phenotype is attributable to overactivation of β-catenin signaling. Our results demonstrate that in muscle stem cells, APC dampens canonical Wnt signaling to allow cell cycle progression and radically diverge from previous observations concerning stem cells in actively self-renewing tissues.

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.

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