Project description:Neural crest cells are migratory progenitor cells that contribute to nearly all tissues and organs throughout the body. Their formation, migration and differentiation are regulated by a multitude of signaling pathways, that when disrupted can lead to disorders termed neurocristopathies. While work in avian and amphibian species has revealed essential factors governing the specification and induction of neural crest cells during gastrulation and neurulation in non-mammalian species, their functions do not appear to be conserved in mice, leaving major gaps in our understanding of neural crest cell formation in mammals. Here we describe Germ Cell Nuclear Factor (GCNF/Nr6a1), an orphan nuclear receptor, as a critical regulator of neural crest cell formation in mice. Gcnf null mutant mice, exhibit a major disruption of neural crest cell formation. The purpose of this experiment is to examine gene expression changes in response to Gcnf mutation in E9.0 mouse embryos.
Project description:Comparative principles of DNA methylation reprogramming during human and mouse in vitro primordial germ cell specification [Mouse smallRNA-Seq]
Project description:Neural crest cells are migratory progenitor cells that contribute to nearly all tissues and organs throughout the body. Their formation, migration and differentiation are regulated by a multitude of signaling pathways, that when disrupted can lead to disorders termed neurocristopathies. While work in avian and amphibian species has revealed essential factors governing the specification and induction of neural crest cells during gastrulation and neurulation in non-mammalian species, their functions do not appear to be conserved in mice, leaving major gaps in our understanding of neural crest cell formation in mammals. Here we describe Germ Cell Nuclear Factor (GCNF/Nr6a1), an orphan nuclear receptor, as a critical regulator of neural crest cell formation in mice. Gcnf null mutant mice, exhibit a major disruption of neural crest cell formation. The purpose of this experiment is to examine gene expression changes in response to Gcnf mutation in anterior and posterior cranial regions of E9.25 mouse embryos.
Project description:Differentiation of human embryonic stem cells (hESCs) provides a unique opportunity to study the epigenetic mechanisms that facilitate cellular transitions in a human context. To that end, we performed comprehensive transcriptional and epigenetic profiling of early populations derived through directed differentiation of hESCs representing each of the three embryonic germ layers. Integration of whole genome bisulfite sequencing, chromatin immunoprecipitation-sequencing and RNA-Sequencing reveals unique events associated with specification towards each lineage. While we observe expected dynamics such as loss of DNA methylation and gain of H3K4me1 at distal putative regulatory elements, we frequently found a germ layer specific switch to H3K27me3 at sites of high DNA methylation in the undifferentiated state. By carefully dissecting these initial events, we may be able to devise more faithful differentiation strategies and gain novel insights in to the robust rewiring of regulatory programs during cellular transitions. 10 Samples in total, 5 in replicate. To better understand the interplay of epigenetic dynamics and transcription factor binding upon in vitro specification of human embryonic stem cells we profiled OCT4, SOX2 and NANOG in hESC and the endoderm master regulatory factor FOXA2 in in vitro derived endoderm cells (dEN). To gain further insights into the relation of DNA methylation and TF binding, we carried out ChIP-bisulfite sequencing for FOXA2 in dEN. Lastly, we were interested in the fate of genes bound by FOXA2 in dEN upon further differentiation and therefore differentiated dEN further towards a hepatocyte like state and performed RNA-Seq.
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.