Abstract:

In order to study the relationship between the CAST gene polymorphism and meat quality of 5 sheep breeds（Gansu alpine fine wool sheep， Small tail han sheep， Tibetan， Mongolian sheep and Tansheep which were fed in a typical farming mode of Gansu province） in Gansu Province at the molecular level and to explore the possibility of improving the quality of sheep meat by using CAST as a candidate gene， the polymorphism of intron 3 of CAST gene was detected by PCRSSCP in 5 sheep breeds， and the association between CAST gene polymorphism and meat quality in 9monthold sheep was analyzed. The results showed: compared with allele A，two mutations were detected which included G62T and C110T in allele B while only C92T was detected in allele C. The mutations formed AA， AB， BB and AC genotypes. Experimental results showed that 5 sheep breeds were in nonHardyWeinberg equilibrium state. Population genetic polymorphism analysis showed that the polymorphism information content （PIC） of the 5 sheep breeds was moderate. The association analysis showed that the water loss rate of AC genotype was significantly higher than those of others （P<005）， the shear forcer of AC was significantly lower than those of other three genotypes （P<005）. Genotype analysis of different sheep breeds showed that the water loss rate of AC genotype was significantly higher than other three genotypes （P<005） ， and the shear stress of AC genotype was significantly lower than other genotypes（P<005） except Mongolia sheep. The mutation locus had no significant influence on eye muscle area. These associations showed CAST gene could be used as a candidate gene for markerassisted selection of sheep meat performance and meat quality.

Key words: sheep, PCRSSCP, CAST gene, meat quality traits, association analysis