Unique and Specific mA RNA Methylation in Mouse Embryonic and Postnatal Cerebral Cortices.

N-methyladenosine (mA)-mediated epitranscriptomic regulation is critical for various physiological processes. Genetic studies demonstrate that proper mA-methylation is required for mouse brain development and function. Revealing landscapes of mA-methylation in the cerebral cortex at different developmental stages will help to understand the biological meaning of epitranscriptomic regulation. Here, we depict the temporal-specific mA-methylation status in mouse embryonic and postnatal cortices using methylated RNA immunoprecipitation (MeRIP) sequencing. We identified unique mA binding motifs in stage-specific RNAs and found that more RNA transcripts are temporally methylated in embryonic cortices than in postnatal ones. Moreover, we found that cortical transcription factors and genes associated with neurological disorders are broadly as well specifically methylated at mA sites. Our study highlights the importance of epitranscriptomic regulation in the developing cortex and provides a fundamental reference for future mechanistic examinations of mA methylation-mediated gene expression regulation in normal brain development and neurological disorders.