Single Nucleotide Polymorphisms in Calpastatin Gene and the Association with Growth Traits in Tibetan sheep (Ovis aries)

The calpastatin gene has been extensively studied as a candidate gene because of its regulatory function within muscle development of animals. However, little is known about the association between variation of the calpastatin gene and growth traits in Tibetan sheep. Using DNA sequencing, four single nucleotide polymorphisms (SNPs) g.3844A>G, g.88874T>C, g.89126C>T and g.89157A>C were identified in this study. An association analysis indicates that the g.3844A>G and g.89126C>T polymorphisms affected body weight (P<0.05). The g.89157A>C polymorphism was a significantly correlated with body weight and chest circumference (P<0.05). The quantitative real-time polymerase chain reaction (qPCR) analysis revealed that the expression of calpastatin gene presented an increasing trend with an increase in age. Remarkably lower mRNA expression was detected at the fetal stage compared with adult ewes (P<0.05). These findings indicated that the calpastatin gene polymorphisms were involved in growth-related traits in Tibetan sheep, which can be considered as genetic markers for improving the growth traits of Chinese Tibetan sheep.