The Study Of MTNR1A Gene In The Influence Of Sika Deer And Its Polymorphism

Antler trait is one of the main economic traits of the sika deer. Improving antler trait can promote deer industry development. Antler trait of sika deer is a restricted trait. The cycle of traditional breeding is long and the effect is slow. But the molecular marker-assisted selection can select early, save the cost of breeding and improve efficiency. It is of great significance in theory and practice.In this study, Wu San (Shuangyang species) and Dong Feng (Dong Feng species) sika deer are the 2 populations for experiments. Using SNP to study MTNR1A, at the same time, analysis relationship between different groups and sika deer antler trait. According to the MTNR1A genes published in NCBI (NC-007328.3), we designed 7 primers and got the sika deer’s MTNR1A gene sequences using sequencing technology. Therefore we used PCR-SSCP, AS-PCR to detect the MTNR gene polymorphism in exon2 and get 3 bases mutations. Meanwhile, we analysed the relationship between genetic polymorphisms and antler traits. The results showed that:1. Using 7 pairs of primers to PCR, only 1 PCR products had polymorphism and the mutation sites on exon2 of MTNR1A gene.2. We got the MTNR1A gene sequences of its 2 exons by sequencing. On the measurement of sika deer MTNR1A sequences and the cow MTNR1A gene sequences, the results shows that they have homology of 98%. And the other species were compared MTNR1A and found that homology was also high. This shows MTNR1A is highly the conservative genes.3. In Wu San and the Dong Feng special sika deer fields were detected 3 mutations in exon2 of MTNR1A. Each mutation also contains 2 alleles and 3 genotypes. There is a T-C mutation of 518bp in exon2 of MTNR1A. But it can not change amino acids; The locus of 629bp in exon2 of MTNR1A is discovered G-C mutation, and it changes amino acids, it makes arginine became tryptophan. We definited these 3 genotypes were GG, GC and CC type; There is a T-C mutation of 635bp in exon2 of MTNR1A. Also it can not change amino acids. By construcing three-dimensional structure of MTNR1A, we know that the amino acid of 518bp is in the inner membrane; the amino acid of 629bp is in the signaling molecules domain; the amino acid of 635bp is on the surface of membrane. We predicted that the change of 629bp and 635bp may affect MTNR1A’s function. 4 By Hardy-Weinberg test, the loci of 629bp and 635bp are equilibrium in Wusan. They are disequilibrium in Dongfeng. The locus of 518 is disequilibrium in Wusan and Dongfeng.5. Application of SPASS17.0, we analysed correlation between MTNR1A genotype and antler estimate in the least squares. Correlation analysis shows that only the change of 629bp affect antler production. Genotype of GG is the dominant type.