Fuente: PubMed "meat" Food Chem (Oxf). 2025 Dec 11;12:100339. doi: 10.1016/j.fochms.2025.100339. eCollection 2026 Jun.ABSTRACTSkeletal muscles (SM) development and intramuscular fat (IMF) accumulation are critical determinants of meat quality and yield in chickens. While numerous myogenesis- or adipogenesis-related regulators have been identified in chickens, the coordinated regulation of both SM development and IMF accumulation remains poorly studied. MicroRNAs (miRNAs) have increasingly been implicated in myogenesis or adipogenesis by post-transcriptional regulating target gene expression; however, evidence on their coordinated regulation of both SM development and IMF accumulation in chickens is lacking. In this study, time-series transcriptomes for miRNA and mRNA expression were generated from breast muscle tissues of commercial Arbor Acres (AA) broilers across different developmental stages. Weighted gene co-expression network analysis and differential expression analysis revealed ten miRNAs as key regulators of chicken IMF deposition and SM development. Notably, miR-34c-5p simultaneously modulates the proliferation of both chicken primary myoblasts (CPMs) and chicken intramuscular preadipocytes (CIPs), and CPMs myogenic differentiation and CIPs adipogenic differentiation. Mechanistically, miR-34c-5p suppresses AASS gene expression by directly binding to its 3'-untranslated region (3'UTR), thereby coordinately regulating chicken myogenesis and adipogenesis. Collectively, these findings revealed the synchronous regulation of miR-34c-5p in IMF deposition and SM development by silencing its target AASS gene in chickens. These insights enhance our understanding of the regulatory mechanisms underlying IMF deposition and SM development and potential possible genetic targets to improve meat yield and quality in chickens.PMID:41502551 | PMC:PMC12769826 | DOI:10.1016/j.fochms.2025.100339