ABSTRACT
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.
ABSTRACT
Laminin (LN) proteins are important components of extracellular matrix. These proteins regulate cell proliferation, differentiation, migration, and tissue repair. The LN family has 12 genes that encode 5 α, 4 β, and 3 γ proteins. LamininA5 (LAMA5) as an important gene can support pluripotent cell growth and have been widely studied. However, porcine LAMA5 is absent in all tested porcine genomic databases so far. In this study, we confirmed for the first time the existence of porcine LAMA5 through bioinformatics analysis, and verified this result by cDNA cloning and sequencing. To reveal the expression pattern of Laminin gene family, we detected the expression of Laminin genes in porcine tissues, somatic cells, and porcine induced pluripotent stem cells (piPSCs). The results showed that an alternative splicing variant of Laminin B1 (LAMB1-a) was found exclusively in all tested piPSCs. The expression of this alternative splicing variant is positively correlated with the pluripotent state of piPSCs. The above findings provide evidences and foundations for the father use of LN as extracellular matrix to facilitate the derivation and culture of porcine pluripotent stem cells.