Project description:Precisely co-ordinated activation of lineage specific transcription factors direct cell fate decisions during mouse early development. The T-box transcription factor Eomes is dynamically expressed during mouse gastrulation and is a key regulator of the anterior visceral endoderm (AVE), cardiac mesoderm and definitive endoderm (DE) lineages. The cis-acting regulatory elements that direct spatiotemporally restricted Eomes expression domains have yet to be elucidated. To understand transcriptional regulation of Eomes in Definitive Endoderm open chromatin data was generated by ATAC-seq and histone modifications identified by ChIP-seq. Interactions at the Eomes locus and the loci of two related transcription factors Foxa2 and Lhx1, was also determined by NG Capture-C.
Project description:Precisely co-ordinated activation of lineage specific transcription factors direct cell fate decisions during mouse early development. The T-box transcription factor Eomes is dynamically expressed during mouse gastrulation and is a key regulator of the anterior visceral endoderm (AVE), cardiac mesoderm and definitive endoderm (DE) lineages. The cis-acting regulatory elements that direct spatiotemporally restricted Eomes expression domains have yet to be elucidated. To understand transcriptional regulation of Eomes in Definitive Endoderm open chromatin data was generated by ATAC-seq and histone modifications identified by ChIP-seq. Interactions at the Eomes locus and the loci of two related transcription factors Foxa2 and Lhx1, was also determined by NG Capture-C.
Project description:Precisely co-ordinated activation of lineage specific transcription factors direct cell fate decisions during mouse early development. The T-box transcription factor Eomes is dynamically expressed during mouse gastrulation and is a key regulator of the anterior visceral endoderm (AVE), cardiac mesoderm and definitive endoderm (DE) lineages. The cis-acting regulatory elements that direct spatiotemporally restricted Eomes expression domains have yet to be elucidated. To understand transcriptional regulation of Eomes in Definitive Endoderm open chromatin data was generated by ATAC-seq and histone modifications identified by ChIP-seq. Interactions at the Eomes locus and the loci of two related transcription factors Foxa2 and Lhx1, was also determined by NG Capture-C.
Project description:Enhancers play key roles in gene regulation. However, comprehensive enhancer discovery is challenging because most enhancers, especially those affected in complex diseases, have weak effects on gene expression. Through gene regulatory network modeling, we identified that dynamic cell state transitions, a critical missing component in prevalent enhancer discovery strategies, can be utilized to improve the cells’ sensitivity to enhancer perturbation. Guided by the modeling results, we performed a mid-transition CRISPRi-based enhancer screen utilizing human embryonic stem cell definitive endoderm differentiation as a dynamic transition system. The screen discovered a comprehensive set of enhancers (4 to 9 per locus) for each of the core lineage-specifying transcription factors (TFs), including many enhancers with weak to moderate effects. Integrating the screening results with enhancer activity measurements (ATAC-seq, H3K27ac ChIP-seq) and three-dimensional enhancer-promoter interaction information (CTCF looping, Hi-C), we were able to develop a CTCF loop-constrained Interaction Activity (CIA) model that can better predict functional enhancers compared to models that rely on Hi-C-based enhancer-promoter contact frequency. Together, our dynamic network-guided enhancer screen and the CIA enhancer prediction model provide generalizable strategies for sensitive and more comprehensive enhancer discovery in both normal and pathological cell state transitions.
Project description:Understanding the molecular mechanisms controlling early cell fate decisions in mammals is a major objective towards the development of robust methods for the differentiation of human pluripotent stem cells into clinically relevant cell types. Here, we used human embryonic stem cells (hESCs) to study specification of definitive endoderm in vitro. Using a combination of whole genome expression and ChIP-seq analyses, we established a hierarchy of transcription factors regulating endoderm specification. Importantly, pluripotency factors, namely NANOG, OCT4 and SOX2 have an essential function in this network by actively directing differentiation. Indeed, these transcription factors control the expression of EOMES, which marks the onset of endoderm specification. In turn, EOMES interacts with SMAD2/3 to initiate the transcriptional network governing endoderm formation. Together, these results provide for the first time a comprehensive molecular model connecting the transition from pluripotency to endoderm specification during mammalian development. ChIP-Seq of Eomesodermin binding in human embyonic stem cells, differentiated towards an endodermal fate for 48h in chemically-defined culture media. Includes an input DNA control. Supplementary file GSE26097_README.txt contains descriptions of the raw data files and processed data files.
Project description:Investigation of the role played by GATA6 in establishing the definitive endoderm chromatin accessbility profile. We used pluripotent stem cells as a model of early development. We derived GATA6-/- pluripotent cells with an inducible GATA6 construct that permits exongenous GATA6 cDNA expression upon supplmentation of doxycycline. We differentiated GATA6 +/+ and GATA6-/- (with and without doxycyline) cells to definitive endoderm and analyzed the chromatin profile using ATAC-seq.
Project description:Understanding the molecular mechanisms controlling early cell fate decisions in mammals is a major objective towards the development of robust methods for the differentiation of human pluripotent stem cells into clinically relevant cell types. Here, we used human embryonic stem cells (hESCs) to study specification of definitive endoderm in vitro. Using a combination of whole genome expression and ChIP-seq analyses, we established a hierarchy of transcription factors regulating endoderm specification. Importantly, pluripotency factors, namely NANOG, OCT4 and SOX2 have an essential function in this network by actively directing differentiation. Indeed, these transcription factors control the expression of EOMES, which marks the onset of endoderm specification. In turn, EOMES interacts with SMAD2/3 to initiate the transcriptional network governing endoderm formation. Together, these results provide for the first time a comprehensive molecular model connecting the transition from pluripotency to endoderm specification during mammalian development.