Polymorphisms Of MC4R And POU1F1 Genes And Its Associations With Several Growth Traits In Raccoon Dog

Raccoon dog whose fur is soft, light, beautiful and generous is a very valuable fur animal with high economic value. Its by-product has high development and utilization of value. Currently, the breeding industry of raccoon develops rapidly and raccoon product occupies an important position in the international market. There are numerous studies about breeding industry and feed, management and disease prevention and control technology has been quite mature. But breeding of raccoon has also been the traditional method, that method has not only a long cycle, but also has high cost and inaccuracy. From the 1980s, the rapid development of various genetic markers as DNA polymorphism makes molecular genetic markers used in animal breeding.Growth traits of animals is controlled by several genes, it is proved that MC4R and POU1F1 gene has an important regulatory role on the growth of animals after a number of tests. MC4R gene which is an important signaling molecule of regulation of energy balance and energy homeostasis can control animal appetite, weight and energy metabolism. As a trans-factor POU1F1 has important effects on growth and development of life by activating transcription of growth hormone gene (GH), prolactin gene (PRL) and thyrotrophic gene subunit (TSH(3). Therefore, this test selects MC4R and POU1F1 genes as a candidate gene, and 226 raccoons of Zhoujia farm are as experimental subjects, SNPs of the whole MC4R and part of POU1F1 gene is detected by PCR-SSCP method, and the correlation between polymorphism and growth traits caused by each mutation is analyzed. The main results are as follows:1. MC4R gene research results(1) The whole MC4R genes 1239bp are cloned, the homology of MC4R gene with human is 88% by BLAST comparative analysis in Genbank; the homology of MC4R gene with fox and dog is 98%; the homology of MC4R gene with panda is 92%; the homology of MC4R gene with wild boar is 87%.(2) Three mutations A43G, A143G and T241C are detected in MC4R-1 primer, the three mutation sites generate AA, AB and BB genotypes. The multiple comparisons show that:weight and bust of BB-type are higher than AA-type and AB-type, the difference is significant (P<0.05); the difference between AA-type and AB-type is not significant (P>0.05).(3) CC, CD and DD genotypes are detected by SSCP analysis product of MC4R-6 PCR of primers, it causes by A118C mutant by clone and sequence analysis. The least squares analysis shows that:the mutations affect weight of the whole test group (P<0.2); in males, it has a significant effect on the length of the body (P <0.05) and has no effect on the rest of growth traits (P>0.2). (4) EE, EF and FF genotypes are detected by SSCP analysis product of MC4R-7 PCR of primers, it causes by A42G and Cl 14A mutant by clone and sequence analysis. The least squares analysis shows that:the two mutations affect weight and body length of the whole test group (P<0.2) and has no effect on the rest of growth traits (P>0.2).(5) Statistical analysis after combining genotypes shows that:BBEF is the optimal genotype, the average weight is 6.224kg, it is significantly higher than BB-type (the average weight is 5.899kg) and EF-type (the average weight is 5.320kg). The minimum weight of ABFF-type raccoon is 5.000kg.2. POU1F1 gene research results(1) Exon 4 of raccoon POU1F1 gene is cloned, the sequence length is 150bp, the sequence has been submitted to GenBank (Accession No:GU361626). The homology of this section with dog is 100% by BLAST comparative analysis in Genbank; the homology of this section with cattle is 94%; the homology of this section with chimpanzee and human is 92%; the homology of this section with brown rat is 88%; the homology of this section with zebra fish is 84%; the homology of this section with jungle fowl is 83%.(2) Polymorphism detection is done for this section with SSCP method, there is no polymorphism detected in different test individuals.