Comprehensive analysis of the expression patterns and function of the axis in yak tissues and muscle satellite cells.

Background: The long interspersed nuclear element 1 () retrotransposon has been identified as a specific substrate for fat mass and obesity-related gene (), which facilitates the removal of N-methyladenosine modifications from its targeted RNAs.

Methods: This study examined the dynamic interaction between and in yak tissues and muscle satellite cells, utilizing RT-qPCR, RNA immunoprecipitation (RIP), immunofluorescence staining, and techniques involving overexpression and interference of and to elucidate the relationship between and in yak tissues and muscle satellite cells.

Results: Cloning and analysis of the coding sequence in Jiulong yak revealed a conserved protein structure across various breeds, with notable homology observed with domestic yak, domestic cattle, and Java bison. Comprehensive examination of and gene expression patterns in Jiulong yaks revealed consistent trends across tissues in both sexes. mRNA levels were markedly elevated in the heart and kidney, while RNA was predominantly expressed in the heart. Immunoprecipitation confirmed the direct interaction between the FTO protein and RNA in yak tissues and muscle satellite cells. The - axis was confirmed by a significant decrease in RNA enrichment following its expression interference in yak muscle satellite cells. Overexpression of substantially reduced the expression of recombinant myogenic factor 5 (). However, interference had no discernible effect on and myoblast determination protein 1 () mRNA levels. Immunofluorescence analysis revealed no alterations in Ki-67 protein expression following interference or overexpression. However, phalloidin staining demonstrated enhancement in the myotube fusion rate of yak muscle satellite cells upon interference.

Conclusion: This comprehensive mapping of the and mRNA expression patterns establishes a direct interaction between the protein and RNA in yak. The findings suggest that overexpression promotes muscle satellite cells differentiation, whereas negatively regulates myotube fusion. The study provides fundamental insights into the role of the - axis in determining the fate of muscle satellite cells in yak, laying a solid theoretical foundation for future investigations.