Molecular Mechanisms Underlying Differences in Athletic Ability in Racehorses Based on Whole Transcriptome Sequencing

This study aimed to compare blood samples from Yili horses with outstanding and average performance in 5000 m races through transcriptome sequencing, identify key differentially expressed genes, lncRNAs, and circRNAs, as well as related enriched pathways, and elucidate their regulatory networks. This study used six healthy four-year-old Yili stallions as subjects, divided into an excellent group (E group, n = 3) and an ordinary group (O group, n = 3) based on their 5000-m race performance. Blood RNA-Seq technology was used to analyze differentially expressed mRNAs, lncRNAs, and circRNAs. A total of 2298 mRNAs, 264 lncRNAs, and 215 circRNAs were identified as differentially expressed. Key genes such as EGR1, FOSB, MRPL1, LOC100049811, SIRPB2, and CYTB regulate athletic performance. These genes and their associated RNAs synergistically participate in energy metabolism, protein homeostasis, and muscle remodeling processes, revealing the molecular mechanisms influencing athletic performance and providing important references for identifying candidate genes associated with equine athletic performance.