| Semen quality is considered as one of the most important traits of breeder cocks’ fertility.The quality of semen plays an important role in fertilization rate of hatching egg and production performance of progeny.The detection of semen quality to choose excellent breeder cocks for production is an important guarantee on poultry industry. The polymorphisms of gene BSG, SPEE1, SPATA4, SPAG6, P’2X7and ANXA7in Beijing-You male chickens were studied, the associations between the genotypes and semen quality traits were analyzed in this research. Real-time fluorescent quantitative PCR was used to analyze the difference of mRNA expression of those genes between high, middle and low semen volume in testicular.The study aims to affort references for selection of related candidate genes on semen quality and application of molecular marker-assisted selection,and lay the foundations for breeding research of Beijing-You chicken’s fertility.MALDI-TOF-MS SNP technology was applied to classify the genotypes of89male Beijing-You chickens aged35weeks. After identifying the haplotype with Phase and Haploview software, the linear model was constructed for association analysis.89male Beijing-You chickens aged58weeks, which selected at the base of result from test1, were assigned to3group (high,middle and low)according semen volume, to study the mRNA expression of candidate genes of high,middle and low semen volume in testicular, results were as follows:1.Candidate genes were screened out of the16SNPs, associated with the unit of analysis point of discovery, C29756T and T23041C loci in gene SPAG6were signifi-cantly associated with semen volume,sperm motility and sperm deformity rate (P<0.05). T23041C site in CC genotype was a high volume of semen sperm motility-low sperm deformity rate of dominant genotype;C3422A site in gene SPATA4was sign-ificantly correlated the sperm deformity rate, sperm concentration,semen pH value, weight and testicular weight (P<0.05);here in, genotype AA of C3422A locus was a high weight-high testicular weight of the dominant genotype, and A3329C site was significantly associated with testicular weight (P<0.05); C4294T locus in BSG gene was significantly associated with comb weight (P<0.05); G3399and C5699T loci in SPEE1gene were significantly associated with body weight (P<0.05);A139G site in gene P2X7was significantly associated with semen volume,sperm deformity rate and meat beard weight (P<0.05),and genotype AA was the advantage genotypes of high semen volume-low sperm deformity rate genotypes,C4184T and A10579G sites were significantly associated with sperm motility (P<0.05);G6862A locus in gene ANXA7was significantly associated with sperm density (P<0.05).A13854T site was significantly associated with semen (P<0.05),and G14234A site was signifi-cantly related with comb weight (P<0.05).2.C29756T and T23041C were significantly associated with semen volume, sperm motility and sperm abnormality (P<0.05);the haplotypes were significantly assoc-iated with the traits of semen volume and sperm abnormality (P<0.05). Chickens with H4H4haplotype showed significantly higher semen volume,and lower sperm abnorm-ality than that with H2H3and H3H3haplotypes,indicating that H4H4haplotype com-bination was a high semen volume-high sperm motility-sperm motility-low sperm abnormality rate of the advantages of genotypes; H2H3haplotype was favorable haplotype combinations for comb traits.3.Real-time quantitative PCR detection in testicular showed that:the mRNA expressions of BSG, SPEE1, SPATA4and ANXA7in low semen volume treatment were significantly lower than high and middle treatments (P<0.05); but the mRNA expressions of P2X7in different treatments had no significant difference (P>0.05); the mRNA expressions of SPAG6in high semen volume treatment were significantly higher than low and middle treatments (P<0.05),this gene maybe plays a key role in spermiogenesis of breeder cocks to insure the integrity of sperm head.4.SPAG6, SPATA4genes can be used as the high quality of semen in chickens screening candidate genes.In T23041C site of SPAG6gene, CC genotype and H4H4haplotype combination can be used as the dominant genotype and combinations in high semen quality cocks,respectively.In C3422A in SPATA4gene, AA genotype is the dominant genotype for body weight-testicular traits of cock selection. |
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