Genomic insights into selection signatures and candidate genes for milk production traits in buffalo population

Abstract

Genetic variability in livestock driven by selection leaves distinct signatures within the genome. However, the comprehensive landscape of the selection responses for milk production traits in the Chinese buffalo population remains elusive. This study employed an integrated haplotype score (iHS) and runs of homozygosity (ROH) analyses of whole-genome sequence data from 100 Chinese buffaloes to decipher selection signatures. Using iHS and ROH, we identified 1 046 and 1 045 significant genomic regions, containing 717 and 263 candidate genes, respectively. The integration of iHS and ROH revealed 258 candidate regions and 108 overlapping genes, representing true selection signatures. Additionally, 94 candidate regions overlapped with 672 previously reported quantitative trait loci associated with key economically important traits. Annotation of the genomic regions highlighted candidate genes linked to milk production traits, including SNORD42, COX18, ANKRD17, ALB, RASSF6, CXCL8, TMEM232, ARHGAP26, and NR3C1. Transcriptome-wide association analysis supported ANKRD17 and CEP41 as potential candidates for affecting milk traits. This study unveils a comprehensive selection signature profile for the Chinese buffalo population by integrating iHS and ROH methods. The findings have broad implications for improving milk production traits in buffalo populations globally, contributing to more sustainable livestock systems. The identified candidate genes shed light on the selection response for milk production traits, offering crucial insights into optimising the breeding strategies for Chinese buffaloes.