Identification of CircRNA-Related ceRNA Networks in the Longissimus Dorsi of Yaks at Different Developmental Stages

We investigated the expression profiles and functions of CircRNAs in the longissimus dorsi muscle of Datong yaks at different developmental stages, with the aim of clarifying their regulatory roles in skeletal muscle development. Samples of longissimus dorsi muscle were collected from Datong yaks at three developmental stages: 90-day-old fetuses, 6-month-old juveniles, and 3-year-old adults. High-throughput RNA sequencing was performed to identify CircRNAs. Differential expression analysis, along with GO and KEGG enrichment analyses, was conducted. A competing endogenous RNA (ceRNA) regulatory network was subsequently constructed to screen for core CircRNAs. A total of 17,027 CircRNAs were identified, with 6821 being differentially expressed. These differentially expressed CircRNAs showed significant enrichment in skeletal muscle development-related functions, such as sarcomere and calcium ion homeostasis, and were involved in key pathways, including the FoxO (Forkhead box O) and calcium signaling pathways. Construction of the ceRNA network revealed 20 core CircRNAs (e.g., CircRNA_10402 and CircRNA_15445), which may modulate the expression of 84 mRNAs by competing for binding with 42 miRNAs. This study preliminarily reveals the dynamic regulatory network of CircRNAs during skeletal muscle development in Datong yaks, providing new theoretical insights for understanding the molecular mechanisms underlying yak muscle development and for molecular breeding.