scholarly journals The EGL-13 SOX Domain Transcription Factor Affects the Uterine Cell Lineages in Caenorhabditis elegans

Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1623-1628
Author(s):  
Hediye Nese Cinar ◽  
Keri L Richards ◽  
Kavita S Oommen ◽  
Anna P Newman

Abstract We isolated egl-13 mutants in which the cells of the Caenorhabditis elegans uterus initially appeared to develop normally but then underwent an extra round of cell division. The data suggest that egl-13 is required for maintenance of the cell fate.

Genetics ◽  
2019 ◽  
Vol 212 (3) ◽  
pp. 773-788
Author(s):  
Françoise Simon ◽  
Anne Ramat ◽  
Sophie Louvet-Vallée ◽  
Jérôme Lacoste ◽  
Angélique Burg ◽  
...  

Cell diversity in multicellular organisms relies on coordination between cell proliferation and the acquisition of cell identity. The equilibrium between these two processes is essential to assure the correct number of determined cells at a given time at a given place. Using genetic approaches and correlative microscopy, we show that Tramtrack-69 (Ttk69, a Broad-complex, Tramtrack and Bric-à-brac - Zinc Finger (BTB-ZF) transcription factor ortholog of the human promyelocytic leukemia zinc finger factor) plays an essential role in controlling this balance. In the Drosophila bristle cell lineage, which produces the external sensory organs composed by a neuron and accessory cells, we show that ttk69 loss-of-function leads to supplementary neural-type cells at the expense of accessory cells. Our data indicate that Ttk69 (1) promotes cell cycle exit of newborn terminal cells by downregulating CycE, the principal cyclin involved in S-phase entry, and (2) regulates cell-fate acquisition and terminal differentiation, by downregulating the expression of hamlet and upregulating that of Suppressor of Hairless, two transcription factors involved in neural-fate acquisition and accessory cell differentiation, respectively. Thus, Ttk69 plays a central role in shaping neural cell lineages by integrating molecular mechanisms that regulate progenitor cell cycle exit and cell-fate commitment.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jerome Korzelius ◽  
Sina Azami ◽  
Tal Ronnen-Oron ◽  
Philipp Koch ◽  
Maik Baldauf ◽  
...  

Abstract In adult epithelial stem cell lineages, the precise differentiation of daughter cells is critical to maintain tissue homeostasis. Notch signaling controls the choice between absorptive and entero-endocrine cell differentiation in both the mammalian small intestine and the Drosophila midgut, yet how Notch promotes lineage restriction remains unclear. Here, we describe a role for the transcription factor Klumpfuss (Klu) in restricting the fate of enteroblasts (EBs) in the Drosophila intestine. Klu is induced in Notch-positive EBs and its activity restricts cell fate towards the enterocyte (EC) lineage. Transcriptomics and DamID profiling show that Klu suppresses enteroendocrine (EE) fate by repressing the action of the proneural gene Scute, which is essential for EE differentiation. Loss of Klu results in differentiation of EBs into EE cells. Our findings provide mechanistic insight into how lineage commitment in progenitor cell differentiation can be ensured downstream of initial specification cues.


2017 ◽  
Author(s):  
Hidenori Nakaoka ◽  
Yuichi Wakamoto

AbstractReplicative aging has been demonstrated in asymmetrically dividing unicellular organisms, seemingly caused by unequal damage partitioning. Although asymmetric segregation and inheritance of potential aging factors also occurs in symmetrically dividing species, it nevertheless remains controversial whether this results in aging. Based on large-scale single-cell lineage data obtained by time-lapse microscopy with a microfluidic device, in this report, we demonstrate the absence of replicative aging in old-pole cell lineages ofSchizosaccharomyces pombecultured under constant favorable conditions. By monitoring more than 1,500 cell lineages in seven different culture conditions, we showed that both cell division and death rates are remarkably constant for at least 50–80 generations. Our measurements revealed that the death rate per cellular generation increases with division rate, pointing to a physiological trade-off with fast growth under balanced growth conditions. We also observed the formation and inheritance of Hsp104-associated protein aggregates, which are a potential aging factor in old-pole cell lineages, and found that these aggregates exhibited a tendency to preferentially remain at the old-poles for several generations. However, the aggregates were eventually segregated from old-pole cells upon cell division and probabilistically allocated to new-pole cells. The quantity and inheritance of protein aggregates increased neither cellular generation time nor cell death initiation rates. Furthermore, our results revealed that unusually large amounts of protein aggregates induced by oxidative stress exposure did not result in aging; old-pole cells resumed normal growth upon stress removal, despite the fact that most of them inherited significant quantities of aggregates. These results collectively indicate that protein aggregates are not a major determinant of cell fate inS. pombe, and thus cannot be an appropriate molecular marker or index for replicative aging under both favorable and stressful environmental conditions.


2019 ◽  
Author(s):  
Filip Z. Klawe ◽  
Thomas Stiehl ◽  
Peter Bastian ◽  
Christophe Gaillochet ◽  
Jan U. Lohmann ◽  
...  

AbstractCoordination of fate transition and cell division is crucial to maintain the plant architecture and to achieve efficient production of plant organs. In this paper, we analysed the stem cell dynamics at the shoot apical meristem (SAM) that is one of the plant stem cells locations. We designed a mathematical model to elucidate the impact of hormonal signaling on the fate transition rates between different zones corresponding to slowly dividing stem cells and fast dividing transit amplifying cells. The model is based on a simplified two-dimensional disc geometry of the SAM and accounts for a continuous displacement towards the periphery of cells produced in the central zone. Coupling growth and hormonal signaling results in a non-linear system of reaction-diffusion equations on a growing domain with the growth velocity depending on the model components. The model is tested by simulating perturbations in the level of key transcription factors that maintain SAM homeostasis. The model provides new insights on how the transcription factor HECATE is integrated in the regulatory network that governs stem cell differentiation.SummaryPlants continuously generate new organs such as leaves, roots and flowers. This process is driven by stem cells which are located in specialized regions, so-called meristems. Dividing stem cells give rise to offspring that, during a process referred to as cell fate transition, become more specialized and give rise to organs. Plant architecture and crop yield crucially depend on the regulation of meristem dynamics. To better understand this regulation, we develop a computational model of the shoot meristem. The model describes the meristem as a two-dimensional disk that can grow and shrink over time, depending on the concentrations of the signalling factors in its interior. This allows studying how the non-linear interaction of multiple transcription factors is linked to cell division and fate-transition. We test the model by simulating perturbations of meristem signals and comparing them to experimental data. The model allows simulating different hypotheses about signal effects. Based on the model we study the specific role of the transcription factor HECATE and provide new insights in its action on cell dynamics and in its interrelation with other known transcription factors in the meristem.


Development ◽  
1994 ◽  
Vol 120 (2) ◽  
pp. 443-451 ◽  
Author(s):  
L.G. Edgar ◽  
N. Wolf ◽  
W.B. Wood

We have analysed early transcription in devitellinized, cultured embryos of the nematode Caenorhabditis elegans by two methods: measurement of [32P]UTP uptake into TCA-precipitable material and autoradiographic detection of [3H]UTP labelling both in the presence and absence of alpha-amanitin. RNA synthesis was first detected at the 8- to 12-cell stage, and alpha-amanitin sensitivity also appeared at this time, during the cleavages establishing the major founder cell lineages. The requirements for maternally supplied versus embryonically produced gene products in early embryogenesis were examined in the same culture system by observing the effects of alpha-amanitin on cell division and the early stereotyped lineage patterns. In the presence of high levels of alpha-amanitin added at varying times from two cells onward, cell division continued until approximately the 100-cell stage and then stopped during a single round of cell division. The characteristic unequal early cleavages, orientation of cleavage planes and lineage-specific timing of early divisions were unaffected by alpha-amanitin in embryos up to 87 cells. These results indicate that embryonic transcription starts well before gastrulation in C. elegans embryos, but that although embryonic transcripts may have important early functions, maternal products can support at least the mechanics of the first 6 to 7 cell cycles.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 224-224
Author(s):  
Hiromi Iwasaki ◽  
Yojiro Arinobu ◽  
Shin-ichi Mizuno ◽  
Hirokazu Shigematsu ◽  
Kiyoshi Takatsu ◽  
...  

Abstract Here we show that eosinophil progenitors (EoPs) and basophil/mast cell progenitors (BMCPs) are prospectively isolatable in normal hematopoiesis, and that their lineage decisions are regulated principally by GATA-2 and C/EBPα. These progenitors were isolated downstream of granulocyte/monocyte progenitors (GMPs), and BMCPs further generated monopotent basophil progenitors (BaPs) and mast cell progenitors (MCPs). Gene expression analysis showed that neither GATA-1 nor GATA-2 was expressed in GMPs, whereas both of them were upregulated in EoPs, BMCPs, BaPs and MCPs. Importantly, C/EBPα was expressed in EoPs and BaPs as well as GMPs, but was downregulated in BMCPs and MCPs. We have reported that GATA-1 is critical primarily for megakaryocyte/erythrocyte commitment or conversion of stem and progenitor cells. We therefore focused on GATA-2 and C/EBPα functions in this study. Since both EoPs and BaPs co-expressed GATA-2 and C/EBPα while GMPs expressed only C/EBPα, we first transduced GATA-2 into GMPs via a GFP-tagged retrovirus. Strikingly, all GATA-2+ GMPs gave rise to pure eosinophil colonies but not basophil colonies, indicating that enforced GATA-2 can instruct GMPs to become EoPs. Next, since BMCPs only expressed GATA-2 but not C/EBPα, we maintained the expression of C/EBPα in GMPs by retroviral transduction. Interestingly, the sustained expression of C/EBPα blocked basophil/mast cell differentiation from GMPs, indicating that C/EBPα downregulation is required for GMPs to choose the basophil/mast cell fate. As a reciprocal experiment, we conditionally disrupted C/EBPα gene at the level of GMPs by retrovirally transducing Cre gene into GMPs purified from mice in which C/EBPα gene is flanked by loxP sequences (floxed: F). The frequency of mast cell read-out from C/EBPα-disrupted GMPs was 5-fold higher than that from C/EBPα F/F (Cre−) GMPs. C/EBPα-disrupted GMPs, however, did not give rise to BaPs. Furthermore, MCPs transduced with C/EBPα were converted into BaPs. Thus, C/EBPα is required to be reactivated during transition from BMCPs to BaPs. We further tested their interplay in specification of these lineages by using common lymphoid progenitors (CLPs), which do not express GATA-2 or C/EBPα. We enforced the expression of each transcription factor in CLPs in different orders by using the two-step retroviral transduction system. Interestingly, C/EBPα transduction reprogrammed CLPs into GM lineages, and subsequently-transduced GATA-2 instructed C/EBPα + CLPs to select the eosinophil fate. Next, we switched the order of transduction. Strikingly, GATA-2 transduction converted CLPs into BMCPs, and subsequently-transduced C/EBPα specified GATA-2+ CLPs to become BaPs. Thus, at the branchpoint for EoPs and BMCPs, GATA-2 upregulation instructed EoP development if C/EBPα was present, whereas it instructed BMCP development if C/EBPα was absent. After the BMCP stage, C/EBPα had to remain suppressed for MCP development, whereas BaPs developed by C/EBPα reactivation. These data collectively suggest that the order of expression of GATA-2 and C/EBPα is critical for their interplay to selectively activate developmental programs for the eosinophil, the basophil and the mast cell lineages.


Genetics ◽  
2009 ◽  
Vol 183 (3) ◽  
pp. 965-977 ◽  
Author(s):  
Annina C. Spilker ◽  
Alexia Rabilotta ◽  
Caroline Zbinden ◽  
Jean-Claude Labbé ◽  
Monica Gotta

PAR proteins (partitioning defective) are major regulators of cell polarity and asymmetric cell division. One of the par genes, par-1, encodes a Ser/Thr kinase that is conserved from yeast to mammals. In Caenorhabditis elegans, par-1 governs asymmetric cell division by ensuring the polar distribution of cell fate determinants. However the precise mechanisms by which PAR-1 regulates asymmetric cell division in C. elegans remain to be elucidated. We performed a genomewide RNAi screen and identified six genes that specifically suppress the embryonic lethal phenotype associated with mutations in par-1. One of these suppressors is mpk-1, the C. elegans homolog of the conserved mitogen activated protein (MAP) kinase ERK. Loss of function of mpk-1 restored embryonic viability, asynchronous cell divisions, the asymmetric distribution of cell fate specification markers, and the distribution of PAR-1 protein in par-1 mutant embryos, indicating that this genetic interaction is functionally relevant for embryonic development. Furthermore, disrupting the function of other components of the MAPK signaling pathway resulted in suppression of par-1 embryonic lethality. Our data therefore indicates that MAP kinase signaling antagonizes PAR-1 signaling during early C. elegans embryonic polarization.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sandeep Gopal ◽  
Aqilah Amran ◽  
Andre Elton ◽  
Leelee Ng ◽  
Roger Pocock

AbstractCommunication between the soma and germline optimizes germ cell fate programs. Notch receptors are key determinants of germ cell fate but how somatic signals direct Notch-dependent germ cell behavior is undefined. Here we demonstrate that SDN-1 (syndecan-1), a somatic transmembrane proteoglycan, controls expression of the GLP-1 (germline proliferation-1) Notch receptor in the Caenorhabditis elegans germline. We find that SDN-1 control of a somatic TRP calcium channel governs calcium-dependent binding of an AP-2 transcription factor (APTF-2) to the glp-1 promoter. Hence, SDN-1 signaling promotes GLP-1 expression and mitotic germ cell fate. Together, these data reveal SDN-1 as a putative communication nexus between the germline and its somatic environment to control germ cell fate decisions.


2018 ◽  
Author(s):  
Françoise Simon ◽  
Anne Ramat ◽  
Sophie Louvet-Vallée ◽  
Jérôme Lacoste ◽  
Angélique Burg ◽  
...  

AbstractCell diversity in multicellular organisms relies on coordination between cell proliferation and the acquisition of cell identity. The equilibrium between these two processes is essential to assure the correct number of determined cells at a given time at a given place. Here, we show that Tramtrack-69 (Ttk69, a BTB-ZF transcription factor ortholog of the human PLZF factor) plays an essential role in controlling this balance. In theDrosophilabristle cell lineage, producing the external sensory organs composed by a neuron and accessory cells, we show thatttk69loss of function leads to supplementary neural-type cells at the expense of accessory cells. Our data indicate that Ttk69 (1) promotes cell-cycle exit of newborn terminal cells by downregulatingcycE, the principal cyclin involved in S-phase entry and (2) regulates cell fate acquisition and terminal differentiation by downregulating the expression ofhamletand upregulating that ofSuppressor of Hairless, two transcription factors involved in neural-fate acquisition and accessory-cell differentiation, respectively. Thus, Ttk69 plays a central role in shaping neural cell lineages by integrating molecular mechanisms that regulate progenitor cell-cycle exit and cell-fate commitment.Summary statementTramtrack-69, a transcription factor orthologous to the human tumor-suppressor PLZF, plays a central role in precursor cell lineages by integrating molecular mechanisms that regulate progenitor cell-cycle exit and cell-fate determination.


2020 ◽  
Vol 10 (9) ◽  
pp. 3071-3085
Author(s):  
Wendy Aquino-Nunez ◽  
Zachery E Mielko ◽  
Trae Dunn ◽  
Elise M Santorella ◽  
Ciara Hosea ◽  
...  

Abstract Identifying the mechanisms behind neuronal fate specification are key to understanding normal neural development in addition to neurodevelopmental disorders such as autism and schizophrenia. In vivo cell fate specification is difficult to study in vertebrates. However, the nematode Caenorhabditis elegans, with its invariant cell lineage and simple nervous system of 302 neurons, is an ideal organism to explore the earliest stages of neural development. We used a comparative transcriptome approach to examine the role of cnd-1/NeuroD1 in C. elegans nervous system development and function. This basic helix-loop-helix transcription factor is deeply conserved across phyla and plays a crucial role in cell fate specification in both the vertebrate nervous system and pancreas. We find that cnd-1 controls expression of ceh-5, a Vax2-like homeobox class transcription factor, in the RME head motorneurons and PVQ tail interneurons. We also show that cnd-1 functions redundantly with the Hox gene ceh-13/labial in defining the fate of DD1 and DD2 embryonic ventral nerve cord motorneurons. These data highlight the utility of comparative transcriptomes for identifying transcription factor targets and understanding gene regulatory networks.


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