Project description:Here we determine the map of RNA methylation (m6A) in mouse embrionic stem cells, and Mettl3 knock out cells Examination of m6A modification sites on the transcriptome of mouse Embryonic stem cells and Embryonic Mettl3 knock out cells, using a m6A specific antibody.
Project description:N6-methyl-adenosine (m6A) is the most abundant modification on messenger RNAs and is linked to human diseases, but its functions in mammalian development are poorly understood. Here we reveal the evolutionary conservation and function of m6A by mapping the m6A methylome in mouse and human embryonic stem cells. Thousands of messenger and long noncoding RNAs show conserved m6A modification, including transcripts encoding core pluripotency transcription factors. m6A is enriched over 3M-bM-^@M-^Y untranslated regions at defined sequence motifs, and marks unstable transcripts, including transcripts turned over upon differentiation. Genetic inactivation or depletion of mouse and human Mettl3, one of the m6A methylases, led to m6A erasure on select target genes, prolonged Nanog expression upon differentiation, and impaired ESCM-bM-^@M-^Ys exit from self-renewal towards differentiation into several lineages in vitro and in vivo. Thus, m6A is a mark of transcriptome flexibility required for stem cells to differentiate to specific lineages. Examing m6A modification differences in two different cell types
Project description:N6-methyladenosine (m6A) has been recently identified as a conserved epitranscriptomic modification of eukaryotic mRNAs, but its features, regulatory mechanisms, and functions in cell reprogramming are largely unknown. Here, we report m6A modification profiles in the mRNA transcriptomes of four cell types with different degrees of pluripotency. Comparative analysis reveals several features of m6A, especially gene- and cell-type-specific m6A mRNA modifications. We also show that microRNAs (miRNAs) regulate m6A modification via a sequence pairing mechanism. Manipulation of miRNA expression or sequences alters m6A modification levels through modulating the binding of METTL3 methyltransferase to mRNAs containing miRNA targeting sites. Increased m6A abundance promotes the reprogramming of mouse embryonic fibroblasts (MEFs) to pluripotent stem cells; conversely, reduced m6A levels impede reprogramming. Our results therefore uncover a role for miRNAs in regulating m6A formation of mRNAs and provide a foundation for future functional studies of m6A modification in cell reprogramming. m6A-seq in ESC, iPSC, NSC and sertoli cells.
