Analysis Of Polymorphisms Of PR Gene And PRLR Gene And The Relationship With Semen Quality In Bulls

Progesterone receptor (PR) has a close relationship with biological effect in female animals. Its relationship with biological effect in male is not that clear. But recent research proved that progesterone receptor affects male animals'reproductive activities. PR gene has a relationship with not only female's reproductive tissues in the aspects of growth, development, function, but also with male sterility. The exons and 5′UTR polymorphisms of PR gene in bulls were detected in this reserch by PCR-SSCP. The result showed that polymorphisms in exon 4, exon 8 and 5′UTR were detected in this population, there was no polymorphism in other exons; sequencing result indicated that there was a A20G mutation in exon 4, no amino acid alteration by this mutation. There were two mutations in exon 8, G86T and A207T , and they led to Gly-to-Val and Gln-to-His substitutions respectively. G-1809A and C-1808G mutations occurred in 5′UTR. Then relationships between genetypes and performances was analyzed, the results indicated that genetic polymorphisms of exon 4 and exon 8 significantly correlated with partial semen quality performances. Among the totle, for exon 4, BB genotype has a significant influence on that, the ejaculation level is much higher than genotype AA and genotype AB; for exon 8, genotype CC has a more ratio in live semen (frozen) than genotype CD. However, genotype CC is quite a lot lower than genotype CD according to semen density.Prolactin receptor regulates some functions in animals, such as breeding, lactating, growth, development, endocrine and metabolism, ect. PRLR has been detected in many kinds of tissues in several mammals, including brain, overies, placenta and uterus. And this gene can be defined as an essential candidate gene for reproductive trait. Respecting its several complex fuctions for breeding as reported, taking it as a candidate gene, the exons and 5′UTR polymorphisms of PRLR gene in bulls were detected in this reserch by PCR-SSCP. The result showed that polymorphisms in exon 1 and exon 8 were detected in this population, there was no polymorphism in other exons and 5′UTR; sequencing result indicated that there was a C135T mutation in exon 1,. There were two mutations in exon 8, G52A and T53C , no amino acid alterations by these mutations. Then relationship between genetypes and performances was analyzed, the results indicated that genetic polymorphisms of exon 1 and exon 8 significantly correlated with partial semen quality performances. Statistic results showed that, in the mutation of exon 1, genotype EF has a much lower ratio in fresh semen Ac integrity. For exon 8, three genotypes from two alleles also have fine genetic polymorphisms, and have obvious disdinctions in the frozen semen traits of vigor, among which there is no much difference between two homozygotic types while the heterozygosis type's frozen vigor level is remarkably higher than the homozygotic types.