Muscle fibre transition and transcriptional changes of horse skeletal muscles during traditional Mongolian endurance training

Abstract

BackgroundTraditional Mongolian endurance training is an effective way to improve the athletic ability of the horse for endurance events and is widely used. This incorporates aerobic exercise and intermittent fasting and these altered physiologic conditions are associated with switches between muscle fibre types.ObjectivesTo better understand the adaption of horse skeletal muscle to traditional Mongolian endurance training from muscle fibre characteristics and transcriptional levels and to explore possible molecular mechanisms associated with the endurance performance of horses.Study designBefore‐after study.MethodsMuscle fibre type switches and muscle transcriptome changes in six Mongolian horses were assessed during 4 weeks of training. Transcriptomic and histochemical analyses were performed. The activities of oxidative and glycolytic metabolic enzymes were analysed and we generated deep RNA‐sequencing data relating to skeletal muscles.ResultsA fast‐to‐slow muscle fibre transition occurred in horse skeletal muscles, with a concomitant increase of oxidative enzyme activity and decreased glycolytic enzyme activity. Numerous differentially expressed genes were involved in the control of muscle protein balance and degradation. Differential alternative splicing events were also found during training which included exon‐skipping events in Ttn that were associated with muscle atrophy. Differentially expressed noncoding RNAs showed connections with muscle protein balance‐related pathways and fibre type specification via the post‐transcriptional regulation of miRNA.Main limitationsThe study focuses on horse athletic ability only from the aspect of muscular adaptation.ConclusionTraditional Mongolian endurance training‐induced muscle fibre transition and metabolic and transcriptional changes. Muscle‐specific non‐coding RNAs could contribute to these transcriptomic changes during training.

Determination of speed and assessment of conditioning in horses submitted to a lactate minimum test—alternative approaches

“…Although our work is innovative, it is important to recognize its limitations. The present trial can be considered a before-and-after study ( Bou et al, 2024 ) since there was no non-training control. It should be noted that the horses in the study were kept under a pasture regime, which ensured voluntary-spontenous exercise.…”

Identification of Differentially Expressed Genes after Endurance Runs in Karbadian Horses to Determine Candidates for Stress Indicators and Performance Capability

“…Studies in this area have shown repeatedly how closely intertwined the various metabolic pathways are, on the one hand, and how environmental factors can have a modeling effect on expression, on the other hand. Bou et al [39] showed that endurance training leads to alternative splicing and exon-skipping events as well as differentially expressed noncoding RNAs. The modulation of noncoding RNAs, which ultimately causes altered post-transcriptional regulation of gene expression and, thus, metabolic as well as immune adaptation, in response to exercise were shown in various studies [25].…”