scholarly journals The Krüppel-like factor Cabut has cell cycle regulatory properties similar to E2F1

2021 ◽  
Vol 118 (7) ◽  
pp. e2015675118
Author(s):  
Peng Zhang ◽  
Alexia J. Katzaroff ◽  
Laura A. Buttitta ◽  
Yiqin Ma ◽  
Huaqi Jiang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Stem Cell ◽  
Cyclin E ◽  
Intestinal Stem Cell ◽  
Cell Cycle Gene ◽  
Large Set ◽  
Gene Promoters ◽  
Cell Divisions ◽  
Stem Cell Divisions

Using a gain-of-function screen in Drosophila, we identified the Krüppel-like factor Cabut (Cbt) as a positive regulator of cell cycle gene expression and cell proliferation. Enforced cbt expression is sufficient to induce an extra cell division in the differentiating fly wing or eye, and also promotes intestinal stem cell divisions in the adult gut. Although inappropriate cell proliferation also results from forced expression of the E2f1 transcription factor or its target, Cyclin E, Cbt does not increase E2F1 or Cyclin E activity. Instead, Cbt regulates a large set of E2F1 target genes independently of E2F1, and our data suggest that Cbt acts via distinct binding sites in target gene promoters. Although Cbt was not required for cell proliferation during wing or eye development, Cbt is required for normal intestinal stem cell divisions in the midgut, which expresses E2F1 at relatively low levels. The E2F1-like functions of Cbt identify a distinct mechanism for cell cycle regulation that may be important in certain normal cell cycles, or in cells that cycle inappropriately, such as cancer cells.

scholarly journals Visceral mesoderm signaling regulates assembly position and function of the Drosophila testis niche

2021 ◽  
Author(s):  
Lauren Anllo ◽  
Stephen DiNardo
Keyword(s):  
Cell Cycle ◽  
Stem Cell ◽  
Tissue Homeostasis ◽  
Visceral Mesoderm ◽  
Cell Divisions ◽  
Cell Pool ◽  
Stem Cell Divisions ◽  
Drosophila Testis ◽  
And Function ◽  
Stem Cell Pool

SummaryTissue homeostasis often requires a properly placed niche to support stem cells. The morphogenetic processes that position a niche are just being described. We recently showed that Drosophila testis pro niche cells, specified at disparate positions during early gonadogenesis, must assemble in one collective at the gonad anterior. Here, we identify Slit and FGF signals emanating from adjacent visceral mesoderm (Vm) that regulate assembly. In response to signaling, niche cells express islet, which we find is also required for positioning the niche. Without signaling, niche cells specified furthest from the anterior are unable to migrate, remaining dispersed. Function of the dispersed niche is severely disrupted, with pro-niche cells evading cell cycle quiescence, compromised in their ability to signal the incipient stem cell pool, and failing to orient stem cell divisions properly. Our work identifies both extrinsic signaling and intrinsic responses required for proper assembly and placement of the testis niche.

scholarly journals A hybrid model connecting regulatory interactions with stem cell divisions in the root

2021 ◽  
Vol 2 ◽  
Author(s):  
Lisa Van den Broeck ◽  
Ryan J. Spurney ◽  
Adam P. Fisher ◽  
Michael Schwartz ◽  
Natalie M. Clark ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hybrid Model ◽  
Regulatory Networks ◽  
Quiescent Center ◽  
Specific Expression ◽  
Agent Based ◽  
Cell Divisions ◽  
Cell Type Specific Expression ◽  
Stem Cell Divisions ◽  
Cell Niche

Abstract Stem cells give rise to the entirety of cells within an organ. Maintaining stem cell identity and coordinately regulating stem cell divisions is crucial for proper development. In plants, mobile proteins, such as WUSCHEL-RELATED HOMEOBOX 5 (WOX5) and SHORTROOT (SHR), regulate divisions in the root stem cell niche. However, how these proteins coordinately function to establish systemic behaviour is not well understood. We propose a non-cell autonomous role for WOX5 in the cortex endodermis initial (CEI) and identify a regulator, ANGUSTIFOLIA (AN3)/GRF-INTERACTING FACTOR 1, that coordinates CEI divisions. Here, we show with a multi-scale hybrid model integrating ordinary differential equations (ODEs) and agent-based modeling that quiescent center (QC) and CEI divisions have different dynamics. Specifically, by combining continuous models to describe regulatory networks and agent-based rules, we model systemic behaviour, which led us to predict cell-type-specific expression dynamics of SHR, SCARECROW, WOX5, AN3 and CYCLIND6;1, and experimentally validate CEI cell divisions. Conclusively, our results show an interdependency between CEI and QC divisions.

The role of lin-22, a hairy/enhancer of split homolog, in patterning the peripheral nervous system of C. elegans

Development ◽  
1997 ◽  
Vol 124 (15) ◽  
pp. 2875-2888 ◽  
Author(s):  
L.A. Wrischnik ◽  
C.J. Kenyon
Keyword(s):  
Stem Cell ◽  
Regulatory Gene ◽  
Epidermal Cells ◽  
Body Axis ◽  
Wild Type ◽  
Hox Gene ◽  
C Elegans ◽  
Cell Divisions ◽  
Body Regions ◽  
Stem Cell Divisions

In C. elegans, six lateral epidermal stem cells, the seam cells V1-V6, are located in a row along the anterior-posterior (A/P) body axis. Anterior seam cells (V1-V4) undergo a fairly simple sequence of stem cell divisions and generate only epidermal cells. Posterior seam cells (V5 and V6) undergo a more complicated sequence of cell divisions that include additional rounds of stem cell proliferation and the production of neural as well as epidermal cells. In the wild type, activity of the gene lin-22 allows V1-V4 to generate their normal epidermal lineages rather than V5-like lineages. lin-22 activity is also required to prevent additional neurons from being produced by one branch of the V5 lineage. We find that the lin-22 gene exhibits homology to the Drosophila gene hairy, and that lin-22 activity represses neural development within the V5 lineage by blocking expression of the posterior-specific Hox gene mab-5 in specific cells. In addition, in order to prevent anterior V cells from generating V5-like lineages, wild-type lin-22 gene activity must inhibit (directly or indirectly) at least five downstream regulatory gene activities. In anterior body regions, lin-22(+) inhibits expression of the Hox gene mab-5. It also inhibits the activity of the achaete-scute homolog lin-32 and an unidentified gene that we postulate regulates stem cell division. Each of these three genes is required for the expression of a different piece of the ectopic V5-like lineages generated in lin-22 mutants. In addition, lin-22 activity prevents two other Hox genes, lin-39 and egl-5, from acquiring new activities within their normal domains of function along the A/P body axis. Some, but not all, of the patterning activities of lin-22 in C. elegans resemble those of hairy in Drosophila.

scholarly journals Unraveling the Control of Cell Cycle Periods during Intestinal Stem Cell Differentiation

2018 ◽  
Vol 115 (11) ◽  
pp. 2250-2258 ◽  
Author(s):  
Richard Ballweg ◽  
Suengwon Lee ◽  
Xiaonan Han ◽  
Philip K. Maini ◽  
Helen Byrne ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cell ◽  
Cell Differentiation ◽  
Stem Cell Differentiation ◽  
Intestinal Stem Cell

scholarly journals Mitochondria regulate intestinal stem cell proliferation and epithelial homeostasis through FOXO

2020 ◽  
Vol 31 (14) ◽  
pp. 1538-1549
Author(s):  
Fan Zhang ◽  
Mehdi Pirooznia ◽  
Hong Xu
Keyword(s):  
Stem Cells ◽  
Cell Proliferation ◽  
Transcription Factor ◽  
Stem Cell ◽  
Electron Transport Chain ◽  
Intestinal Stem Cell ◽  
Stem Cell Proliferation ◽  
Epithelial Homeostasis ◽  
Chain Complexes ◽  
Transport Chain

Deficiencies in electron transport chain complexes increase the activity of FOXO transcription factor in Drosophila midgut stem cells, which impairs stem cell proliferation and enterocyte specification.

scholarly journals Symmetric vs. Asymmetric Stem Cell Divisions: An Adaptation against Cancer?

PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e76195 ◽  
Author(s):  
Leili Shahriyari ◽  
Natalia L. Komarova
Keyword(s):  
Stem Cell ◽  
Cell Divisions ◽  
Stem Cell Divisions
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