Abstract

The aim of the present genome-wide association study (GWAS) was to identify single nucleotide polymorphisms (SNPs) and candidate genes associated with lactose percentage (LP) and lactose yield (LY) in Egyptian buffalo. The phenotypic dataset included 60,318 monthly measures for LP and LY from 1481 animals. A total number of 114 animals with high and low deviated performance were selected for genotyping with Axiom Buffalo Genotyping 90K Array. Genome-wide analysis was performed using a single marker regression. The GWAS revealed 32 significant and seven suggestive SNPs for LP, however; only two suggestive SNPs were identified for LY. The identified genomic regions are overlapped with previously reported QTL in different cattle breeds. In addition, novel genomic loci were detected. The identified genomic regions harbored many candidate genes with biological roles associated with milk production traits, such as TPD52 and ZBTB10 on chromosome 15; AADAT and GALNTL6 on chromosome 3 and COL8A1 and PLOD2 on chromosome 1. Our findings provide the basis to uncover the key markers and candidate genes affecting lactose traits which facilitate the exploration of the genetic mechanisms that control lactose traits variation in Egyptian buffalo.