The transcriptome-wide N6-methyladenosine (m6A) map profiling reveals the regulatory role of m6A in the yak ovary

Abstract

Background and aim Yak estrus is a seasonal phenomenon, probably involving epigenetic regulation of synthesis and secretion of sex hormones as well as growth and development of follicles. N6-methyladenosine (m6A) is the most common internal modification of the eukaryotic mRNA. However, there are no detailed reports on the m6A transcriptome map of yak ovary. Therefore, this study aimed to collected the yak ovarian tissues at three different states of anestrus (YO-A), estrus (YO-F), and pregnancy (YO-P), and obtained the full transcriptome m6A map in yak by MeRIP-seq. Results The HE staining revealed that the number of growing follicles and mature follicles in the ovary during the estrus period was relatively higher than those in the anestrus period and the pregnancy period. The RT-qPCR showed that the expression of METTL3, METTL14, FTO, YTHDC1 were significantly different across different periods in the ovaries, which suggests that m6A may play a regulatory role in ovarian activity. Next, we identified 20,174, 19,747 and 13,523 m6A peaks in the three ovarian samples of YO-A, YO-F and YO-P using the methylated RNA immunoprecipitation sequencing (MeRIP-seq). The m6A peaks are highly enriched in the coding sequence (CDS) region and 3′untranslated region (3′UTR) as well as the conserved sequence of “RRACH.” The GO, KEGG and GSEA analysis revealed the involvement of m6A in many physiological activities of the yak’s ovary during reproductive cycle. The association analysis found that some genes such as BNC1, HOMER1, BMP15, BMP6, GPX3, and WNT11 were related to ovarian functions. Conclusions The comparison of the distribution patterns of methylation peaks in the ovarian tissues across different periods further explored the m6A markers related to the regulation of ovarian ovulation and follicular development in the yak ovary. This comprehensive map provides a solid foundation for revealing the potential function of the mRNA m6A modification in the yak ovary.

Regulatory role of N6-methyladenosine in intramuscular fat deposition in chicken

“…Similarly, the m 6 A methylation sites in the different species and tissues mentioned above are also associated with RRACH conserved sequences. This pattern of modification has been validated by research on humans, chickens, and yak ( Xiong et al, 2021 ; Gu et al, 2022 ; Guo et al, 2022 ; Yu et al, 2023 ) and is corroborated by our findings.…”

RNA N6-methyladenosine profiling reveals differentially methylated genes associated with intramuscular fat metabolism during breast muscle development in chicken

“…Many m 6 A methylation sites were present in the breast muscle at all 3 developmental stages, with these m 6 A peaks primarily enriched in the CDS and 3′ UTR. This modification pattern is similar to that observed in rex rabbits, yaks, and pigs ( Jiang et al, 2019 ; Zhang et al, 2021 ; Guo et al, 2022 ; Luo et al, 2022 ). However, species- and tissue-specific m 6 A methylation patterns were identified in poultry studies.…”

Transcriptomics and metabolomics of blood, urine and ovarian follicular fluid of yak at induced estrus stage

“…Despite its importance in the yak industry, the regulation of estrus in yaks is not well understood, with limited knowledge about the major endocrine and physiological mechanisms that may promote estrus in anestrus animals [ 44 ]. However, recent research on yak estrus is gaining momentum, with scholars conducting comprehensive analyses of the ceRNA network expression profiles of ovarian granulosa cells and cumulus cells in yaks, as well as transcriptome-wide analysis of N6-methyladenosine (m6A) to reveal the regulatory role of m6A in yak ovaries [ 45 , 46 ]. In this study, we investigated the differentially expressed genes and differentially accumulated metabolites in the transcriptome and metabolome of estrous and unestrus yaks to explore the underlying mechanisms of estrus in yaks.…”