Study On The Genetic Diversity And Its Association With Growth Traits In Nanyang Catlle And Jiaxian Red Cattle

PCR-SSCP was used to detect the genetic diversity of the CLPG gene, DLK1 gene, DGAT2 gene in Nanyang catlle and Jiaxian Red cattle, and then the association with the growth traits were analyzed to provide molecular markers for the further breeding of Nanyang cattle and Jiaxian Red cattle. The results showed that:1. The genetic diversity of Nanyang cattle and Jiaxian Red cattlePCR-SSCP was used to detect the genetic diversity of the CLPG gene, the DLK1 gene intron1 locus and the DGAT2 gene intron3 locus, The results showed that: the PIC of the CLPG, DLK1, DGAT2 in Nangyang cattle and Jiaxian Red cattle was 0/0.2256, 0.3749/0.3582, 0.4044/0.3693, respectively, and the Heterozygosity was 0/0.234, 0.5012/0.4103, 0.568/0.4103, respectively.2. The association between the PCR-SSCP polymorphisms and the growth traitsThe correlation analysis between the polymorphism of CLPG gene and the body length, hucklebone width, circumference of cannon bone and body weight of Jiaxian Red cattle revealed that: the body weight and body length were bigger in the individuals with genotype AC which resulted from a C419T mutation.. The individuals with genotype AB had bigger than that with genotype AA and AC. The hucklebone width of individuals with genotype AB was bigger significantly than that with genotype AA (P<0.05) and AC (P<0.01); the circumference of cannon bone of the individuals with genotype AA was better than that of AB (P<0.05). No polymorphism at the locus was detected in Nanyang cattle.The correlation analysis between the polymorphism of CDLK1 gene and the growth showed that some of the growth traits were influenced by the genotype significantly. The difference of the body weight in 6 months was significant between the individuals with genotype AA and AB; Genotype BB could improve the body weight in 6 months and average daily gain significantly; The individuals with genotype AB had higher chest girth in 18 months than that with genotype AA; The individuals with genotype AB had higher hucklebone width in 24 months than that with genotype BB. The genotype showed no influence to the birth weight (P>0.05).The correlation analysis between the polymorphisms of DGAT2 gene intron3 and the growth traits indicated that: the individuals with genotype B had greater body weight in 6 months, body height in 6 month, hucklebone width in 12 months, hucklebone width in 18 month and chest girth in 24 months than that with genotype A and C significantly (P<0.01). Theχ2 Test of Independence at the DGAT2 gene locus between Nanyang cattle and Jiaxian Red cattle revealed that there was no difference (P>0.05).3. The synthetical analysis between CLPG gene and DLK1 geneThe correlation analysis between the combined genotypes of the CLPG gene and DLK1 gene and the product performance showed that: the difference of the height at hip cross between the individuals with genotype AB+AB and AC+AB was significant (P<0.05), AA+BB and AB+BB (P<0.01), AB+BB and AC+BB (P<0.05), and the difference was caused by the mutation of CLPG gene; The difference of the hucklebone width between the individuals with genotype AA+AA and AB+BB was significant (P<0.05), AA+AB and AB+BB (P<0.01), AB+BB and AC+AB (P<0.01), AB+BB and AC+AB (P<0.05), and the difference was caused by the synergic effect of the two genes. There was no difference (P>0.05) between the genotype AA and the genotype AB of the DLK1 gene when the DLK1 gene was analyzed separately, which was because of the influence of the mutation of the CLPG gene to the DLK1 gene that was not eliminated, and the results also proved that the mutation of the CLPG gene influence to the DLK1 gene.