Abstract
BackgroundOocytes maturation and early embryo development were regulated precisely by a series of factors at transcriptional and posttranslational levels. N6-methyladenosine (m6A) is the most prevalent modification in mRNA as a crucial regulator in RNA metabolism and gene regulation. However, the role of m6A on porcine oocyte maturation and early embryogenesis is largely unknown. ResultsHere, we found that oocytes treated with cycloleucine (CL), an inhibitor of m6A, could impair cumulus expansion, elevate mitochondrial reactive oxygen species (ROS) concentration and decreased oocytes maturation which partially caused by disturbed spindle organization and chromosomes alignment. Moreover, our results indicated that the CL treated parthenogenetic embryos arrested at 4-cell stage and showed worse blastocyst quality. CL treatment not only decreased the methylation levels of nucleic acid, H3K4me3 and H3K9me3, while increased the acetylation level of H4K16 during parthenogenetic embryos development in pigs. Furthermore, single cell RNA-seq (scRNA-seq) analysis indicated that CL treatment dramatically elevated the expression of metabolism-related (SLC16A1 and MAIG3 etc.) and maternal related (BTG4, WEE2 and BMP15 etc.) genes at blastocyst stage. ConclusionsTaken together, we found that m6A methylation inhibition by CL impaired porcine oocyte meiosis and early embryonic development via remodeling histone modifications and altering metabolism related gene expression in blastocysts.
Apolipoprotein B-related gene expression and ultrastructural characteristics of lipoprotein secretion in mouse yolk sac during embryonic development