KAT2B Gene Polymorphisms Are Associated with Body Measure Traits in Four Chinese Cattle Breeds.

Abstract

Simple SummaryGenetic improvement is one of the most important keys to overcoming the shortcomings of beef production. Identifying molecular markers related to growth characteristics and meat quality is significant in improving beef cattle breeds. Studies have shown that KAT2B, a transcriptional co-activator regulating the acetylation modification of histones, may be involved in the development and metabolism of muscle and adipose. However, there are no reports on investigating KAT2B genetic variation in Chinese native cattle. Firstly, this manuscript reports the initial bioinformatics analysis of KAT2B, finding that KAT2B protein is highly conserved among ruminants. The KAT2B gene expression profile in Qinchuan cattle was characterized, showing the spatiotemporal specificity of KAT2B gene expression in tissues such as adipose and liver during fetal and adult periods. Then, the investigation of KAT2B gene polymorphisms was carried out. Three SNPs of the KAT2B gene were identified and were found to be correlated with multiple body measurements in Fu, Qinchuan, Yak, and Chaidam cattle. These findings suggest that these three SNPs of KAT2B can serve as the molecular markers to select individuals for beef cattle breed improvement.Identifying molecular markers related to growth characteristics or meat quality is significant for improving beef cattle breeds. K(lysine) acetyltransferase 2B (KAT2B) is a transcriptional co-activator regulating the acetylation modification of histones, which may be involved in the development and metabolism of muscle and adipose. However, investigations of KAT2B genetic variations in Chinese native cattle are still limited. This study aimed to identify crucial single nucleotide polymorphisms (SNPs) influencing the body measurements of Chinese native cattle. Biological evolution and conservation analysis showed that KAT2B was highly conserved among the ruminants. By qPCR assay, KAT2B gene expression was found to be spatiotemporally specific in bovine tissues such as adipose and liver. By the RFLP-PCR method, three SNPs of KAT2B (g.T61908C, g.T62131C, and g.C73406T) were identified in 827 individuals of four Chinese cattle breeds, including Qinchuan (n = 658), Fu (n = 52), Yak (n = 48), and Chaidam (n = 69) cattle. Association analysis between these KAT2B polymorphisms and the body measurements of Chinese native cattle revealed significant observations. The genetic effects of g.T61908C, g.T62131C, and g.C73406T on the associated phenotypes were illustrated in each breed. In Qinchuan cattle, g.T62131C was significantly associated with better body height, chest width, hip width, and withers height, for which TC and/or TT were the advantageous genotype. In Fu cattle, TT genotype of g.T61908C was associated to better body length, while individuals with TT or CC of g.T62131C showed higher circumference of cannon bone than those with TC genotype. In Yak, individuals with TT genotype of g.C73406T had heavier body weight. In Chaidam cattle, TC genotype of g.C73406T was associated to superior body weight, while CC genotype of g.C73406T was associated to superior chest girth and circumference of cannon bone. These findings suggest that KAT2B gene polymorphisms can be used as the molecular markers for the early molecular marker-assisted selection in beef cattle breeding programs.