Genome-Wide Association Study and Meta-Analysis Uncovers Key Candidate Genes for Body Weight Traits in Chickens.

Background: Genome-wide association studies (GWAS) have been extensively employed to elucidate the genetic architecture of body weight (BW) traits in chickens, which represent key economic indicators in broiler production. With the growing availability of genomic data from diverse commercial and resource chicken populations, a critical challenge lies in how to effectively integrate these datasets to enhance sample size and thereby improve the statistical power for detecting genetic variants associated with complex traits.

Methods: In this study, we performed a multi-population GWAS meta-analysis on BW traits across three genetically distinct chicken populations, focusing on BW at 56, 70, and 84 days of age: P1 (N301 Yellow Plumage Dwarf Chicken Line; = 426), P2 (F2 reciprocal cross: High Quality Line A × Huiyang Bearded chicken; = 494), and P3 (F2 cross: Black-bone chicken × White Plymouth Rock; = 223).

Results: Compared to single-population GWAS, our meta-analysis identified 77 novel independent variants significantly associated with BW traits, while gene-based association analysis implicated 59 relevant candidate genes. Functional annotation of BW56- and BW84-associated SNPs (single-nucleotide polymorphisms) 1_170526144G>T and 1_170642110A>G, integrated with tissue-specific regulatory annotations, revealed significant enrichment of enhancer and promoter elements for and in muscle, adipose, and intestinal tissues. Through this meta-analysis and integrative genomics approach, we identified novel candidate genes associated with body weight traits in chickens.

Conclusions: These findings provide valuable mechanistic insights into the genetic mechanisms underlying body weight regulation in poultry and offer important references for selective breeding strategies aimed at improving production efficiency in the poultry industry.