A mutation in POLR2A gene associated with body size traits in Dezhou donkeys revealed with GWAS.

Abstract

The Dezhou donkey is a famous local donkey breed in China. The aim of the present study was to identify the genes associated with the body size traits of the Dezhou donkey and facilitate the breeding activities of the donkeys. A total of 349 donkeys from 2 generations (113 individuals in F0 and 236 in F1) were analyzed with restriction-site-associated DNA sequencing. A genome-wide association study revealed that the region between 13.7 and 15.6 Mb of chromosome 13 is significantly associated with body sizes. Candidate genes related to body size development, including POLR2A, CHRNB1, FGF11, and ZBTB4, were identified. The results of GO and KEGG analysis indicated that the genes involved in many GO terms were related to metabolic processes and developmental processes. Additionally, a T>C mutation (Chr13:14312485) was found at intron 10 of the POLR2A gene. The association analysis showed significant differences among genotypes for the size traits. The body size of the individuals with the TT genotype was significantly higher than that with the CC genotype. The results showed that the polymorphism of POLR2A has the potential to be used as a marker in the breeding programs of the Dezhou donkeys.