# Exercise-Induced Meat Quality Improvement Is Associated with an lncRNA-miRNA-mRNA Network in Tibetan Sheep

## TL;DR

Exercise improves meat quality in Tibetan sheep by changing muscle fibers and fat content through a complex genetic network.

## Contribution

Identified an lncRNA-miRNA-mRNA network linking exercise to meat quality in Tibetan sheep.

## Key findings

- Active Tibetan sheep had finer muscle fibers and higher fat content, improving meat tenderness and flavor.
- Transcriptomic analysis revealed 208 mRNAs and 490 lncRNAs linked to muscle fiber and energy metabolism changes.
- A regulatory network involving lncRNA-miRNA-mRNA interactions was constructed to explain exercise-induced adaptations.

## Abstract

This study addresses the unknown problem of how physical exercise influences meat quality in Tibetan sheep, a unique breed living on the Qinghai–Tibet Plateau. Our goal was to compare sheep kept in limited spaces with those that walked long distances on pastures. We found that active sheep developed finer muscle fibers and higher fat content, which makes their meat more tender, juicy, and flavorful. We also identified specific genetic mechanisms that control these beneficial changes. This work has social value as it guides farmers to improve meat quality through better management practices like grazing. This helps provide better food and promotes the sustainable development of the livestock industry.

Tibetan sheep, a unique breed indigenous to the Qinghai–Tibet Plateau, exhibit remarkable adaptations to high-altitude hypoxia, and their muscle quality is a key economic determinant. However, the molecular mechanisms by which exercise regulates meat quality in this breed remain poorly understood. This study aimed to systematically investigate the effects of different exercise volumes on the biceps femoris muscle of Tibetan sheep, integrating histological analysis with high-throughput transcriptome sequencing. We compared a low-exercise group with a high-exercise group and found that long-term endurance exercise resulted in phenotypic changes suggestive of a shift toward oxidative muscle fiber characteristics. This adaptation was characterized by significantly reduced muscle fiber diameter and cross-sectional area, alongside a crucial increase in intramuscular fat content, collectively enhancing meat tenderness, flavor, and juiciness. Transcriptomic analysis revealed extensive gene expression reprogramming, identifying 208 mRNAs and 490 lncRNAs that were differentially expressed and primarily associated with muscle fiber transition and energy metabolism. Furthermore, we constructed a putative lncRNA-miRNA-mRNA competing endogenous RNA network based on expression correlations and bioinformatic predictions, highlighting potential key regulatory axes such as LOC105603384/miR-16-z/MYLK3, LOC121820630/miR-381-y/NOX4, and LOC132659150/oar-miR-329a-3p/NF1. These findings provide a new perspective on the molecular basis of exercise-induced muscle adaptation in high-altitude animals and offer a solid theoretical framework for improving meat quality through scientific livestock management.