Meat quality is an economically important trait for global food production. Copy number variations (CNVs) have been previously implicated in elucidating the genetic basis of complex traits. In this article, we detected a total of 112,198 CNVs and 10,102 CNV regions (CNVRs) based on the Bovine HD SNP array. Next, we performed a CNV-based genome-wide association analysis (GWAS) of six meat quality traits and identified 12 significant CNV segments corresponding to eight candidate genes, including PCDH15, CSMD3, etc. Using region-based association analysis, we further identified six CNV segments relevant to meat quality in beef cattle. Among these, TRIM77 and TRIM64 within CNVR4 on BTA29 were detected as candidate genes for backfat thickness (BFT). Notably, we identified a 34 kb duplication for meat color (MC) which was supported by read-depth signals, and this duplication was embedded within the keratin gene family including KRT4, KRT78, and KRT79. Our findings will help to dissect the genetic architecture of meat quality traits from the aspects of CNVs, and subsequently improve the selection process in breeding programs.

Body weight is a polygenic trait with intricate inheritance patterns. Functional genomics enriched with multi-layer annotations offers essential resources for exploring the genetic architecture of complex traits. In this study, we conducted an extensive characterization of regulatory variants associated with body weight-related traits in cattle using multi-omics analysis. First, we identified seven candidate genes by integrating selective sweep analysis and multiple genome-wide association study (GWAS) strategies using imputed whole-genome sequencing data from a population of 1577 individuals. Subsequently, we uncovered 3340 eGenes (genes whose expression levels are associated with genetic variants) across 227 muscle samples. Transcriptome-wide association studies (TWASs) further revealed a total of 532 distinct candidate genes associated with body weight-related traits. Colocalization analyses unveiled 44 genes shared between expression quantitative trait loci (eQTLs) and GWAS signals. Moreover, a comprehensive analysis by integrating GWAS, selective sweep, eQTL, TWAS, epigenomic profiling, and molecular validation highlighted a positively selected genomic region on Bos taurus autosome 6 (BTA6). This locus harbors pleiotropic genes (LAP3, MED28, and NCAPG) and a prioritized functional variant involved in the complex regulation of body weight. Additionally, convergent evolution analysis and phenome-wide association studies underscored the conservation of this locus across species. Our study provides a comprehensive understanding of the genetic regulation of body weight through multi-omics analysis in cattle. Our findings contribute to unraveling the genetic mechanisms governing weight-related traits and shed valuable light on the genetic improvement of farm animals.

Fatty acid composition is a complex trait governed by a polygenic architecture. Although numerous genetic variants associated with fatty acids have been id