Project description:To understand the role of Sox7 in primitive endoderm differentiation, we compare the gene expression pattern of Sox7 (+/-) and Sox7 (-/-) ES cells with or without dexamethasome (Dex) treatment. Because these ES cells harbour Gata6-GR transgene, Dex treatment forces ES cells differentate into XEN-like cells. As Sox7 (-/-) ES cells can differentiate into XEN-like cell by morphology, we assessed genome wide gene expression pattern. Sox7 (+/-) ES cells and Sox7 (-/-) ES cells are forced to differentiate into XEN-like cells by Gata6-GR transgene. To compare the gene expression, we collected RNA samples at day4 with or without dexamethasone treatment from each genotype.
Project description:Transcription factor-mediated reprogramming is a powerful method to study cell fate changes. In this work, we demonstrate that the transcription factor Gata6 can initiate reprograming of multiple cell types to induced extraembryonic endoderm (iXEN) cells. Intriguingly, Gata6 is sufficient to drive iXEN cells from mouse pluripotent cells and differentiated neural cells. Furthermore, GATA6 induction in human ES (hES) cells also downregulates pluripotency gene expression and upregulates extraembryonic endoderm genes, revealing a conserved function in mediating this cell fate switch. Profiling transcriptional changes following Gata6 induction in mES cells reveals step-wise pluripotency factor disengagement, with initial repression of Nanog and Esrrb, then Sox2 and finally Oct4, alongside step-wise activation of extraembryonic endoderm genes. Chromatin immunoprecipitation and subsequent high-throughput sequencing analysis shows Gata6 enrichment near both pluripotency and endoderm genes, suggesting that Gata6 functions as both a direct repressor and activator. Together this demonstrates that Gata6 is a versatile and potent reprogramming factor that can act alone to drive a cell fate switch from diverse cell types. (1) Microarray analysis of Gata6 overexpressing cells from 12 to 144 hours of doxycycline treatment in mouse embryonic stem (mES) cells compared to uninduced mES cells, embryo-derived XEN cells and Sox7 overexpressing mES cells after 144 hours of doxycycline treatment. (2) ChIP-seq analysis of Gata6 binding 36 hours following doxycycline treatment. (3) ChIP-seq analysis of Gata6 binding in embryo-derived XEN cells. (4) RNA-seq analysis of GATA6 overexpressing cells following 144 hours of induction in hES cells.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.