Evolutionary and Functional Integration of LCORL-NCAPG Locus with Myostatin Pathway in Broiler Chickens

Introduction: The remarkable growth performance of modern broiler chickens, particularly commercial breeds such as Ross 308 and Cobb 500, has been achieved through decades of intensive genetic selection in countries such as the United States and China. However, the molecular mechanisms underlying this enhanced growth phenotype remain incompletely understood. The present study aimed to evaluate genomic analysis of the LCORL-NCAPG locus in broiler chickens, Ross 308 and Cobb 500, to identify genetic variants, characterize regulatory elements, and investigate potential interactions with the Myostatin (MSTN) pathway.Materials and methods: A comparative genomic analysis of the LCORL-NCAPG locus, located on chromosome 4, a region associated with body size and growth traits across multiple species, was conducted. Using in silico approaches, including sequence analysis, motif prediction, evolutionary conservation profiling, and interaction network construction, genomic sequences from several commercial broiler lines and ancestral populations were analyzed. Genetic variants were identified and annotated using reference genome data (GRCg7b), and regulatory elements were predicted using motif-based scanning and CpG island detection. Functional interactions were explored through network analysis involving components of the MSTN pathway.Results: Broiler-specific variants in the LCORL-NCAPG locus, particularly in exonic and intergenic regions, were identified with signs of positive selection in broiler chicken lines, including higher alternative allele frequencies and conservation of non-coding regulatory elements. Notably, potential novel interactions between the transcription factor LCORL and MSTN were discovered, with LCORL exhibiting predicted interactions with SMAD3 and FOXO1, suggesting a central role in modulating muscle development through the MSTN signaling axis. These findings offered mechanistic insights into how growth-regulatory genes may be co-regulated in muscle tissue.Conclusion: These results improved the understanding of the genetic architecture of growth traits in commercial broiler chickens, highlighting the functional role of the LCORL-NCAPG locus and its interaction with the MSTN pathway. The present findings provided a strong foundation for future functional studies and potential targets for marker-assisted selection programs aimed at optimizing growth performance.