Project description:To explore the effects of Tet on porcine pre-implantation embryogenesis, we utilized Bobcat339, a specific small-molecule inhibitor of the Tet protein, to treat parthenogenetic 4-cell stage embryos.
Project description:We generated RRBS data to enable a comparative DNA methylation analysis of Dnmt1 Tet/Tet, a mouse embyonic stem cell line (ESC) that overexpresses DNMT1 and the WT R1 ESCs and their neuronal derivatives. The optimized data analysis workflows provides a framework for comparative investigations of methylation profiles. This platform offers a comprehensive and more accurate quantitative and qualitative evaluation of methylated cytosines in ESCs and neurons. We expect that RRBS-based methylome analysis permits to understand the epigenetic basis of abnormal neurogenesis.
Project description:TET-family dioxygenases oxidize 5-methylcytosine (5mC) in DNA, and exert tumor suppressor activity in many types of cancers. Even in the absence of TET coding region mutations, TET loss-of-function is strongly associated with cancer. We show that acute elimination of TET function induces the rapid development of an aggressive, fully-penetrant and cell-autonomous myeloid leukemia in mice, pointing to a causative role for TET-loss-of-function in this myeloid malignancy. Phenotypic and transcriptional profiling showed aberrant differentiation of hematopoietic stem/ progenitor cells, impaired erythroid and lymphoid differentiation and strong skewing to the myeloid lineage, with only a mild relation to changes in DNA modification. We also observed progressive accumulation of DNA damage and strong impairment of DNA break repair, suggesting a key role for TET proteins in maintaining genomic integrity.
Project description:Tet-mediated DNA oxidation is a new type of epigenetic modification in mammals and its role in the regulation of cell fate transition remains poorly understood. Here, we derive mouse embryonic fibroblasts (MEFs) deleted in all three Tet genes and examine their capability to be reprogrammed into iPS cells. We demonstrate that these Tet-deficient MEFs cannot be reprogrammed due to a blockage in the mesenchymal-to-epithelial transition (MET). Reprogramming of MEFs deficient in TDG is similarly blocked. The blockage is caused by impaired activation of crucial microRNAs, which depends on oxidative demethylation promoted by Tet and TDG. Reintroduction of either miR-200c or catalytically active Tet and TDG restores reprogramming to the respective knockout MEFs. Thus, oxidative demethylation is essential for somatic cell reprogramming. These findings provide mechanistic insights into the operation of epigenetic barriers in cell lineage conversion. Reduced Representation Bisulfite (RRBS, MspI,~75-400bp size fraction) and Tet-Assisted RRBS (TARRBS) of MEFs & reprogramming MEFs at Day 5