Integrated miRNA–mRNA Analysis Reveals Regulatory Mechanisms of Muscle Fiber Transformation Underlying Meat Quality Variation in Chicken

Chicken muscle fibers are classified as oxidative or glycolytic, with distinct metabolic properties that influence meat quality. However, the molecular mechanisms linking fiber type to quality traits remain unclear. This study compared the pectoralis major (PEM) and soleus (SOL) muscles of Guangyuan Gray chickens, revealing significant differences in fiber characteristics and meat quality. Transcriptome analysis identified key pathways─MAPK, PPAR, and calcium signaling─associated with fiber-type variation. The transcription factor HOXC10, enriched in SOL, showed inverse expression to its predicted regulator, miR-6701-3p. Dual-luciferase assays confirmed HOXC10 as a direct target of miR-6701-3p. Functional studies in skeletal muscle satellite cells demonstrated that miR-6701-3p promotes proliferation, inhibits differentiation, and induces fast-twitch fiber formation, while HOXC10 facilitates slow-twitch fiber development. These findings suggest that the miR-6701-3p/HOXC10 axis may contribute to the regulation of muscle fiber types and be linked to muscle fiber characteristics that are associated with meat quality variation.