[Correlation analysis between polymorphism of the 59383635th locus on X chromosome and fat-tail trait in sheep]

Fat tail or fat rump is one of essential traits for surviving in harsh environments, and the mechanism of fat deposition and its inheritable characters in sheep are still unclear. Therefore, the 59383635th locus on X chromosome in our unpublished chip data was chosen as candidate SNP, PCR-SSCP method was used to detect genotypes in five sheep breeds which have extreme differences in tail types (Altay, Small Tail Han Sheep, Hu, Chinese Merino and Suffolk), and the mathematical model was employed to analyze the correlation between the polymorphism and the trait of fat tail or fat rump. The results in this study showed that the high frequency of allele T exists in Altay flock, and the frequency of allele C appears to be particularly high in the thin tail sheep breeds. The result of mathematical model showed that the ratio of T/C increased exponentially with the increase of phenotype score. These results suggest that there is a big difference in the SNP distribution between fat tail (rump) and thin tail sheep populations, and the SNP can be used as an ideal molecular marker in high-fat or low-fat sheep breeding. However, the biological function of the SNP remains to be further studied.