Project description:Expression response after induction of putative phrenic neuronal determinants in ES cell-derived motor neurons was compared to a pre-determined list of genes over-expressed in FACS-sorted primary. Transcription factor Pou3f1 was identified as a major determinant of phrenic identity.
Project description:To develop molecular indicators of neurodevelopmental disorders related to the exposure to external chemicals, we have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to influence neuronal differentiation from embryonic stem cells. Thalidomide (TMD), bisphenol A (BPA), 4-hydroxy-2,2',3,4',5,5',6-heptachlorobiphenyl (4OH-PCB187) and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) were exposed to human embryonic stem (ES) cell-derived sphere on day 3 after starting sphere formation for 72 hours. Gene expression analysis on the stage of sphere development showed chemical specific characteristics.
Project description:Mouse embryonic stem (ES) cells cultured in defined medium with MEK and GSK3 inhibitors (2i) resemble the pre-implantation epiblast in the ground state, with full development capacity including the somatic lineages and the germline. Although β-catenin is known to be crucial for naive pluripotency of ES cells, the mechanism is not fully understood. Here we showed that β-catenin interacted with a repressive protein complex to maintain the ground state of ES cells by fine-tuning their lineage development potential. Absence of β-catenin impaired ES cell self-renewal without affecting the core self-renewal circuitry of Oct4, Sox2 and Nanog as well as other pluripotency factors. However, β-catenin-deficient cells showed a primed state transcriptional signature with perturbed expression of germline and neuronal lineage genes. Knockdown of Tcf7l1, the repressor in canonical Wnt signaling pathway, did not completely rescue the β-catenin-deficient phenotype of ES cells. Mechanistically, β-catenin formed a novel biochemical complex with E2F6, HP1γ and HMGA2 to restrain ES cells from differentiation by co-occupying the promoters of germline and neuronal lineage regulators independent of TCF7L1. Overall, out work showed that β-catenin maintained ground state ES cells by orchestrating their development plasticity through a repressive protein complex with E2F6, HP1γ and HMGA2.
Project description:Using Chromatin immunoprecipitation combined with Selective Isolation of Chromatin Associated Proteins (ChIP-SICAP), we define the chromatin-bound proteins co-localized with CTCF in mouse embryonic stem cells (ES) and neuronal stem (NS) cells. We uncover the proteins that are differentially co-localized with CTCF in ES and NS cells. We show the link between the underlying role of RNA-binding proteins with consolidation of chromatin structure during mammalian development.
