Polymorphisms in CALCRL and MPC1 Genes and Their Associations with Growth Traits in Tianzhu White Yaks

Single nucleotide polymorphisms (SNPs) may contribute to variation in economically important body traits in yak, but variants near calcitonin receptor-like receptor (CALCRL) and mitochondrial pyruvate carrier 1 (MPC1) have not been characterized in Tianzhu white yak. We evaluated two downstream SNPs in 536 yaks (351 females and 185 males; 2-6 years old) using polymerase chain reaction amplification and Sanger sequencing. Associations with body height, body oblique length, chest circumference, and body weight were analyzed separately using general linear models adjusted for sex and age. The CALCRL gene chr 2:140178268 A > T locus was associated with body weight (p = 0.001). Individuals with AA and AT genotypes had significantly greater body weight than individuals with the TT genotype. The MPC1 gene chr 10:98419837 C > T locus was associated with body height (p = 0.002), chest circumference (p < 0.001), and body weight (p < 0.001), but not body oblique length (p = 0.072); CC individuals generally showed greater values than TT individuals. Both SNPs are downstream non-coding variants. These loci are candidates for further investigation, but independent population validation and functional studies are required before their potential use in breeding programs.