The differences of muscle in Kazakh horses of different ages were investigated based on transcriptome technique

In order to explore the key candidate genes and molecular mechanisms of age-related muscle development in Kazakh horses, transcriptome sequencing was performed on the skeletal muscle of Kazakh horses in three parts at different growth stages. Sixteen Kazakh horses were selected and divided into 4 groups according to age with 4 biological replicates in each group. Tissue samples of longissimus dorsi muscle, abdominal wall muscle and diaphragm were collected for use. The results showed that in the O group VS F group, 434 mRNA differentially up-regulated and 322 down-regulated in longissimus dorsi muscle, 125 up-regulated and 127 down-regulated in abdominal wall muscle, 73 up-regulated and 70 down-regulated in diaphragm muscle. GO enrichment analysis focused on the biological process (BP) and the Oxidative phosphorylation pathway of KEGG signaling pathway (longissoid dorsalis muscle), and this pathway annotated 37 DEGs, including ATP5PF, NDUFB8 and ATP5MG, all of which were downregulated. ECM-receptor interaction (abdominal wall) annotated 7 DEGs, including COL4A2, COL4A1 and ITGA5, while the Hippo signaling pathway (diaphragm) annotated 6 DEGs, including SERPINE1, RASSF1 and FZD10. COL4A1, COL4A2, BMP2, MDH1, Serpine1, ATF3, etc. are the key regulatory genes of muscle development. This study will provide reliable data support and theoretical basis for better exploring the effects of age on equine skeletal muscle development.