[METTL3 regulates expression of pluripotent genes in porcine pluripotent stem cells]

In post-transcriptional mRNA modification, m⁶A has been observed in a wide range of eukaryotes. METTL3, as a component of methyltransferase complex for m⁶A modification, regulates mouse naïve pluripotency and influences mRNA stability, especially affecting the expression level of the key pluripotent transcription factors. To reveal the expression pattern of the porcine METTL3 gene, we analyzed METTL3 expression level in different porcine tissues, somatic cells, and induced pluripotent stem cells (piPSCs) by RT-PCR. To identify the function of METTL3 for regulation of the expression of porcine pluripotent genes, we cloned a 1 859-bp coding sequence of METTL3 and synthesized a shRNA against METTL3. When knocking down METTL3 expression in piPSCs, the cell type of piPSCs became naïve-like morphology, alkaline phosphatase activity was increased, and expression level of pluripotent genes NANOG, OCT4 and LIN28A was significantly elevated. In addition, piPSCs cultured in medium containing 10 mmol/L cycloleucine for 48 h exhibited the similar result as that knocked down METTL3. These findings set the stage for optimization of piPS culture condition and further study on the roles of m6A in piPSCs.