Association Analysis Between The Genetic Polymorphism And The Heat Resistance Of Chinese Holstein Of ISG15 And IL8 Gene

Nowadays,greenhouse effect has been more and more serious,global warming has also became a quite serious problem.In most parte of China,high temperature has been lasting for a long time in summer.Heat stress has became one of the problems which badly need to be solved in dairy production.When the dairy heat stress occurs,cows' metabolism will disorder,the production and reproductive performance of dairy cows will decline,their immunity will reduce,which make them more vulnerable to the invasion of disease,such as Mastitis,Endometriosis and so on.At the same time,heat stress may led to abortion rate and stillbirth rate increased,it will cause considerable economic losses to farms.Therefore,analyzing the correlation between genetic polymorphisms can offer theoretical basis and technical support for the molecular markers to breeding heat-resistant,quality and high-yield dairy cows.In this experiment,we chose 112 Chinese Holstein in heat-stress from Hangzhou,Zhejiang Province,by PCR-SSCP method,the SNPs of ISG15 and IL8 genes were detected in Chinese Holstein.We also analysised the association between the SNPs of ISG15 and IL8 genes with rectal temperature,blood routine,biochemical index in serum of heat-stress Chinese Holstein.The following is the results of this research:(1)The SNPs of ISG15 gene and IL8 gene were detected in Chinese Holstein by PCR-SSCP method.1 mutation in ISG15 gene and 11 mutations in IL8 gene were detected.All mutations belong to moderate polymorphism(0.25<PIC<0.5).x2 test results showed that g.2209 T?C,g.2222G?A and g.2373 G?A in IL8 gene were significantiy deviation from Hardy-Weinberg equilibrium(P<0.05).(2)ISG15 g.844 G?A had litter associated with rectal temperature blood,biochemical index in serum of mild heat-stress Chinese Holstein.(THI=76.1)(3)Association analysis between the SNPs of IL8 gene with rectal temperature blood,biochemical index in serum of heat-stress Chinese Holstein.We found that,IL8 gene had six SNPs were significantly associated with MPV(P<0.05),Among them,g.2784 A?G?g.2857 T?C?g.2983 G?A was significant effect on AST(P<0.05).Chinese Holstein with the genotypes GGCCAA had lowest AST and The content of K+ in serum.IL8 gene g.202 C?T,g.264C?T,g.302 A?G was significantly effect on RBC,HCT,PLT and MDA(P<0.05).The result showed that the content of MDA in serum of Chinese Holstein with the genotypes TTTTGG was significantly lower than genotypes CTCTAG(P<0.05).The content of K+ in serum and rectal temperature of Chinese Holstein with the genotypes TTTTGG all were at a low level.The results suggested that g.202 C?T?g.264 C?T?g.302 A?G and g.2784 A?G?g.2857 T?C?g.2983 G?A SNPs of the IL8 gene may be used as a genetic marker to breeding Chinese Holstein with the character of heat-stress resistance and high producing.