Project description:During primary neurulation, the separation of a single-layered ectodermal sheet into the surface ectoderm (SE) and neural tube specifies SE and neural ectoderm (NE) cell fates. The mechanisms underlying fate specification in conjunction with neural tube closure are poorly understood. Here, by comparing expression profiles between SE and NE lineages, we observed that uncommitted progenitor cells, expressing stem cell markers, are present in the neural plate border/neural fold prior to neural tube closure. To identify what type of signaling pathways and transcriptional factors are involved in the fate specification between SE and NE cells during neurulation.
Project description:During primary neurulation, the separation of a single-layered ectodermal sheet into the surface ectoderm (SE) and neural tube specifies SE and neural ectoderm (NE) cell fates. The mechanisms underlying fate specification in conjunction with neural tube closure are poorly understood. Here, by comparing expression profiles between SE and NE lineages, we observed that uncommitted progenitor cells, expressing stem cell markers, are present in the neural plate border/neural fold prior to neural tube closure.
Project description:The transcription factor p63 is a master regulator of ectoderm development essential for epidermal specification. Although previous studies have highlighted the role of p63 triggering the epidermal transcriptomic program, its precise mechanism of target gene regulation in the complex context of a developing embryo remains poorly understood. Here, we used zebrafish embryos to analyze in vivo how p63 regulates the expression of its target genes during development. We generated tp63-knock-out mutants that recapitulate human phenotypes and show down-regulated epidermal gene expression. Following p63-binding dynamics during development, we found two distinct functions clearly separated in space and time. During early development, p63 binds enhancers associated to neural genes, where it limits Sox3 binding and reduces the expression of these neural genes. Indeed, we show that p63 and Sox3 are co-expressed in the neural plate border. Later in development, p63 binds enhancers associated to epidermal genes and promotes their expression, acting as a pioneer factor, as it binds to non-accessible chromatin and is required for its opening. Therefore, our results suggest that p63 is an important regulator of cell fate decisions during ectoderm specification, promoting the epidermal fate and inhibiting the neural program.
Project description:The transcription factor p63 is a master regulator of ectoderm development essential for epidermal specification. Although previous studies have highlighted the role of p63 triggering the epidermal transcriptomic program, its precise mechanism of target gene regulation in the complex context of a developing embryo remains poorly understood. Here, we used zebrafish embryos to analyze in vivo how p63 regulates the expression of its target genes during development. We generated tp63-knock-out mutants that recapitulate human phenotypes and show down-regulated epidermal gene expression. Following p63-binding dynamics during development, we found two distinct functions clearly separated in space and time. During early development, p63 binds enhancers associated to neural genes, where it limits Sox3 binding and reduces the expression of these neural genes. Indeed, we show that p63 and Sox3 are co-expressed in the neural plate border. Later in development, p63 binds enhancers associated to epidermal genes and promotes their expression, acting as a pioneer factor, as it binds to non-accessible chromatin and is required for its opening. Therefore, our results suggest that p63 is an important regulator of cell fate decisions during ectoderm specification, promoting the epidermal fate and inhibiting the neural program.
Project description:The transcription factor p63 is a master regulator of ectoderm development essential for epidermal specification. Although previous studies have highlighted the role of p63 triggering the epidermal transcriptomic program, its precise mechanism of target gene regulation in the complex context of a developing embryo remains poorly understood. Here, we used zebrafish embryos to analyze in vivo how p63 regulates the expression of its target genes during development. We generated tp63-knock-out mutants that recapitulate human phenotypes and show down-regulated epidermal gene expression. Following p63-binding dynamics during development, we found two distinct functions clearly separated in space and time. During early development, p63 binds enhancers associated to neural genes, where it limits Sox3 binding and reduces the expression of these neural genes. Indeed, we show that p63 and Sox3 are co-expressed in the neural plate border. Later in development, p63 binds enhancers associated to epidermal genes and promotes their expression, acting as a pioneer factor, as it binds to non-accessible chromatin and is required for its opening. Therefore, our results suggest that p63 is an important regulator of cell fate decisions during ectoderm specification, promoting the epidermal fate and inhibiting the neural program.
Project description:In recent years, several studies have shed light into the processes that regulate epidermal specification and homeostasis. We previously showed that a broad-spectrum γ–secretase inhibitor DAPT promoted early keratinocyte specification in human embryonic stem cells triggered to undergo ectoderm specification. Here, we show that DAPT accelerates human embryonic stem cell differentiation and induces expression of the ectoderm protein AP2. Furthermore, we utilize RNA sequencing to identify several candidate regulators of ectoderm specification including those involved in epithelial and epidermal development in human embryonic stem cells. Genes associated with transcriptional regulation and growth factor activity are significantly enriched upon DAPT treatment during specification of human embryonic stem cells to the ectoderm lineage. The human ectoderm cell signature identified in this study contains several genes expressed in ectodermal and epithelial tissues. Importantly, these genes are also associated with skin disorders and ectodermal defects, providing a platform for understanding the biology of human epidermal keratinocyte development under diseased and homeostatic conditions. 6 samples were analyzed, 3 replicates of ETOH treated H1 HESCs and 3 replicates of DAPT treated H1 HESCs
Project description:In recent years, several studies have shed light into the processes that regulate epidermal specification and homeostasis. We previously showed that a broad-spectrum γ–secretase inhibitor DAPT promoted early keratinocyte specification in human embryonic stem cells triggered to undergo ectoderm specification. Here, we show that DAPT accelerates human embryonic stem cell differentiation and induces expression of the ectoderm protein AP2. Furthermore, we utilize RNA sequencing to identify several candidate regulators of ectoderm specification including those involved in epithelial and epidermal development in human embryonic stem cells. Genes associated with transcriptional regulation and growth factor activity are significantly enriched upon DAPT treatment during specification of human embryonic stem cells to the ectoderm lineage. The human ectoderm cell signature identified in this study contains several genes expressed in ectodermal and epithelial tissues. Importantly, these genes are also associated with skin disorders and ectodermal defects, providing a platform for understanding the biology of human epidermal keratinocyte development under diseased and homeostatic conditions.
Project description:Cell fate specification of neural stem/progenitor cells (NSCs) is an intricate developmental process that determines neural cell identity. While transcriptional mechanisms undoubtedly affect this process, translational mechanisms are much less understood. Here we show that deficiency of the chromatin remodeler Chromodomain Helicase DNA binding protein 5 (Chd5) causes transcriptional de-repression of multiple ribosomal subunit genes, increases protein synthesis, and expands the activated stem cell pool leading to perturbation of NSC fate. Compromised H3K27me3 in Chd5 deficient NSCs during early cell fate specification underlies the generation of excessive astrocytes at the expense of neurons at later stages of differentiation. Chd5 expression rescues these cell fate defects while simultaneously reestablishing H3K27me3, and inhibition of the H3K27me3-specific demethylase Utx restores appropriate cell fate specification in NSCs lacking Chd5. These findings define a Chd5-Utx-H3K27me3 axis pivotal in ribosome biogenesis and translation during neurogenesis, consistent with compromised CHD5 being implicated in glioma.
Project description:Background: E2A, encoded by the TCF3 gene locus, belongs to the E protein transcription factor family, which also includes HEB (TCF12) and E2-2 (TCF4), has been suggested to play an important role in leukemogenesis. However, far less is known about the function of E2A in cell-fate regulation of hESCs. Therefore, further understanding of E2A in self-renewal and differentiation of embryonic stem cells may be influenced. In the study, we demonstrated E2A knockout exhibited blocked neural differentiation, which is tightly related to histone modification H3K4me3 and H3K27me3. Methods: The genomic DNA of H3K4me3 and H3K27me3 binding peaks in wild type and E2A knockout neural progenitor cells were generated by ChIP-seq technique using IIIumina Hiseq 2500. Results: A comprehensive human chromatin state of H3K4me3 and H3K27me3 in wild type and E2A knockout neural progenitor cells was provided. Function enrichment, network characteristics and disease association of the binding peaks were analyzed. Conclusion: The dataset could serve as a baseline resource for investigating the potential effects and mechanism of H3K4me3/H3K27me3/E2A complex in neural differentiation period of embryonic stem cells