Elucidation of transcription factors controlling mouse ES cell pluripotency and differentiation

Abstract

Embryonic stem (ES) cells can be maintained in undifferentiated states for indefinite passages and yet retain the potential to differentiate into all cell types. An intricate transcriptional regulatory network is, in part, responsible for maintaining such a pluripotency state. In vitro depletion of components of this network, such as Oct4, Sox2, Nanog, and Zic3, induce distinct cellular differentiation responses. In this thesis, I provide additional details of the regulatory network in ES cell pluripotency through characterization of the transcriptional regulators, REST and Zfp206, which have emerged as regulators of ES cell pluripotency.<br>REST has been shown to repress neuronal gene expression in neuronal stem cells (NSC) and non neuronal cells. Our group has recently shown that REST regulates distinct regulatory pathways in ES cells and NSC. By using genome wide mapping of the binding sites for REST and 5 of its cofactors, as well as gene expression profiling upon loss of REST and each cofactors, I found that the REST complex regulates ES cell pluripotency through recruitment of its cofactors. <br>In addition, using genome wide mapping techniques, I have identified a Zfp206 regulatory network and established a physiological interaction of Zfp206 with Oct4 and Sox2 to further expand our understanding of this transcriptional regulatory network. Genome wide mapping of Zfp206 binding sites with ChIP-seq shows that Zfp206 binding targets are enriched in developmental process, transcription regulation, and embryogenesis. Finally, a knockout of Zfp206 in mice was generated, though phenotyping is still ongoing.<br>