Profiling of N6-methyladenosine methylation in porcine longissimus dorsi muscle and unravelling the hub gene ADIPOQ promotes adipogenesis in an m6A-YTHDF1-dependent manner.

BACKGROUND: Intramuscular fat (IMF) content is a critical indicator of pork quality, and abnormal IMF is also relevant to human disease as well as aging. Although N6-methyladenosine (m6A) RNA modification was recently found to regulate adipogenesis in porcine intramuscular fat, however, the underlying molecular mechanisms was still unclear. RESULTS: In this work, we collected 20 longissimus dorsi muscle samples with high (average 3.95%) or low IMF content (average 1.22%) from a unique heterogenous swine population for m6A sequencing (m6A-seq). We discovered 70 genes show both differential RNA expression and m6A modification from high and low IMF group, including ADIPOQ and SFRP1, two hub genes inferred through gene co-expression analysis. Particularly, we observed ADIPOQ, which contains three m6A modification sites within 3' untranslated and protein coding region, could promote porcine intramuscular preadipocyte differentiation in an m6A-dependent manner. Furthermore, we found the YT521­B homology domain family protein 1 (YTHDF1) could target and promote ADIPOQ mRNA translation. CONCLUSIONS: Our study provided a comprehensive profiling of m6A methylation in porcine longissimus dorsi muscle and characterized the involvement of m6A epigenetic modification in the regulation of ADIPOQ mRNA on IMF deposition through an m6A-YTHDF1-dependent manner.