The Correlation Analysis Between Bulls HSP Gene Polymorphism And Semen Quality And Progeny Performance

This study is aimed to reveal the correlation between HSP gene and progeny performance in bulls in order to provide the theoretical basis for the marker-assisted selection of anti-heat stress cattle. In this experiment,125bp and 233bp fragments of HSP gene named HSPA8 and HSPA1A from 142 bulls was amplified by polymerase chain reaction(PCR),respectively.The genetic polymorphisms in the population were detected by single-strand conformational polymorphism(SSCP) of the HSP gene,and analyzes the association between bulls HSP gene polymorphism and semen quality and progeny performance.Results as follows,1 The PCR-SSCP analysis of HSP geneTwo fragments according to cattle HSPA8 gene exon partial sequence and HSPA1A gene exon partial sequence registered in the NCBI database were amplified using Primer5.0 software design the two specific primers.Detected the polymorphism of HSP gene by PCR-SSCP, and the PCR products were sequenced and sequence analysis was performed. The results indicated that T3358C transition mutations in HSPA8 and A6201C and T6202A transvertion mutations in HSPA1A were founded.T3358C mutation resulted in an amino acid change of valine into isoleucine in HSPA8, and two genoytypes (AA and AB) were found with frequency was 0.5775 and 0.4225, respectively. Chi-square test showed that bulls were in Hardy-Weinberg equilibrium. T6202A mutation resulted in an amino acid change of phenylalanine into isoleucine in HSPA1A, and five genotypes (AA, AB, BB, AC,BC) were found with frequency was 0.345,0.4930,0.0845,0.0352 and 0.04220, respectively. Chi-square test showed that bulls were not in Hardy-Weinberg equilibrium.2 Bulls HSP gene polymorphism and progeny performanceThe relationships between bulls HSP gene polymorphism and progeny performance was analysized by least squares linear model. The results showed that estimated breeding value of milk(EBVM) and 305 days milk yield of individuals (DMYI)with genotype AA were both significantly higher than that with genotype AB (P<0.05) at HSPA8 site.Meanwhile, the EBVM of individuals with genotype BB was significantly higher than that with genotype AC at HSPA1A site (P<0.05), estimated breeding value of protein (EBVP) of individuals with genotype AB was significantly higher than that with genotype AC (P<0.05), and 305 DMYI with genotype AC was significantly higher than that with genotype BB (P<0.05).3 Bulls HSP gene polymorphism and semen quality41 bulls from 2006 to 2009,which came from Shanghai, Nanjing and Henan were selected and the correlation analysis between bulls HSP gene polymorphism and semen quality in different seasons conditions was performed by single factor variance using SPSS17.0 statistical software General Linear Model procedure. The results showed that sperm motility and acrosomal integrity are at the lowest level in summer heat stress period, which are significantly lower than that in the other three seasons (P<0.01). The effects of heat stress on sperm density also varied among seasons, in which the lowest was shown in the begining of autum (P<0.01). The sperm abnomal rate in summer and autum were significantly higher compared to that of in spring and winter (P<0.01). Sperm density(SD), sperm motility(SM) and acrosomal integrity(AI) of individuals with genotype AA were significantly higher than that with genotype AB(P<0.05) in HSPA8, and sperm abnormality rate(SAR) of individuals with genotype AA was significantly lower than that with genotype AB (P<0.05),however, SD of individuals with genotype BC are significantly lower than that with genotype AA (P<0.01) in HSPA1A, SM of individuals with genotype AC was significantly lower than that with genotype AB (P<0.01), SAR of individuals with genotype AB was significantly higher than that with genotype AC (P<0.01).