GENOME-WIDE ASSOCIATION STUDY FOR MILK PRODUCTION IN IRANIAN BUFFALO

A genome wide association study (GWAS) was conducted to identify regions of the genome associated with milk production trait in Iranian water buffaloes. In order to do this study, 303 water buffalo from Azeri (N=207), Khuzestani (N=96) breeds were genotyped with Axiom® Buffalo Genotyping 90K Array. Average of monthly recording of one lactation period were used as phenotypic data for each individual. After adjustments of records for fixed effects, phenotypes were regressed on each single nucleotide polymorphisms (SNP) using a linear regression model by GenABEL package in R. In total, 10 SNPs were identified on BTAs 4, 5, 7, 13, 14, 15 and X as probably associated regions with milk production. These selected SNPs with 400 Kbp neighboring genomic regions were surveyed to find probable candidate genes by annotation. In total, 11 genes identified from the annotation of selected SNPs on the cattle genome (UMD3.1 Bos Taurus). Among the candidate genes identified in these regions, the most important gene that associated with milk production was SCOS2 gene on chromosome BTA5. Further research with additional individual and records is essential to detect associated regions with milk production and to suggestion for commercial application to the genetic improvement.

Keywords:

Genome wide association study , single nucleotide polymorphisms , Azeri and Khuzestani buffalo breeds