The Correlation Between Polymorphism Of GH Gene And The Growth Traits In Sheep

The PCR-SSCP and gene sequencing were applied to detecte the polymorphism of GH gene complete sequence in 320 individuls that comprised of six sheep population, namely Oula Tibetan sheep(short name Oula sheep), Qiaoke Tibetan sheep(short name Qiaoke sheep), Ganjia Tibetan sheep(short name Qiaoke sheep), Small Tailed Han sheep, Genmeny marino, Poll Dorset. And the correlation between genetic polymorp- hisms and growth traits were analyzed by using general linear model(GLM). The results showed that:Among six primer pairs, There were polylnorphsms only in PCR products of Primer GH-P1,Primer GH-E4and Primer GH-P6, there were six locus were detected , which respectrvely were 2 locis, 1loci, 3locis in those three eare.The PCR-SSCP detected results of the 5′flanking region Sequence of GH gene showed : The polymorphism locus controled by two alleles A and B, there were three genotypes AA, AB and BB, and the AA was advantage genotype, the allele A was advantage allele. Chi-square test revealed that all three types of Tibetan-sheep and Small Tailed Han sheep populations was in Hardy-Weinberg equilibrium (P>0.05), Genmeny marino and Poll Dorset populations were not detected polymorphism at this locus. Sequence analysis indicated that the polymorphisms of the GH gene 5′flanking region Sequence were caused by T→C and G→A mutation at base positions 84bp and 85bp in PCR products of Primer GH-P1(at base positions 86bp and 87bp in EF077162),.The result of the correlation between different genotypes with growth traits were analyzed showed: individuals with genotype BB of the least square means of body-weight, body-length and body-height were significantly higher than that with genotypes AA and AB in Oula sheep population (P<0.05), the heart girth was no significant among different genotypes(P>0.05). And The Small Tailed Han sheep growth traits among three genotypes was not significant (P>0.05). Hence,the polymorphism of 5′flanking region locus demonstrated affected significantly Oula sheep on growth development. But it did not affecte for Small Tailed Han sheep on growth development. The PCR-SSCP detected results of GH gene Exon 4 showed: The polymorphism locus controled by two alleles Aand B, there were three genotypes AA, AB and BB, the BB were advantage genotype in all three types of Tibetan-sheep and Small Tailed Han sheep populations, and the AA were advantage genotype in the Genmeny marino and Poll Dorset populations, Chi-square test revealed that in six populations which were all at Non-equilibrium Hardy-Weinberg (P<0.01). Sequence analysis indicated that the polymorphisms of the GH gene Exon 4 were caused by T→C synonymous mutation at base positions 88bp in PCR products of Primer GH-E4(at base positions 1286bp in EF077162). The result of the correlation between different genotypes with growth traits were analyzed showed: individuals with genotype BB of body-weight and body size such as body-length were significantly higher than that with genotypes AA and AB in the Oula sheep and the Small Tailed Han sheep populations (P<0.05), but individuals with genotype AA of the least square means of body-weight and body size such as body-length were significantly or very significantly higher than that with other genotypes in the Genmeny marino and Poll Dorset populations (P<0.05 or P<0.01). Hence,the polymorphism of Exon4 locus demonstrated it related to sheep meat production, and it can be used as an important molecular markers for the sheep meat production.The PCR-SSCP detected results of GH gene 3′UTR showed : The polymorphism locus controled by three alleles A ,B and C, there were four genotypes AA, AB , BB and AC, BB genotype was not detected in the Genmeny marino and Poll Dorset populations, and the AA were advantage genotype in all populations. Chi-square test revealed that in six populations which were all at Non-equilibrium Hardy-Weinberg (P<0.05). Sequence analysis indicated that the polymorphisms of the GH gene 3′UTR sequence were caused by T inset, G→T and C→T (at base positions 1864bp, 1887bp and 1924bp in EF077162). The result of the correlation between different genotypes with growth traits were analyzed showed: All populations growth traits among different genotypes was not significant (P>0.05). Hence, it need to increase the number of sheep breeds and expand the sample number to study the characters associated with the growth trait. The population genetics analysis of the three polymorphism locus showed: all three types of Tibetan-sheep were in low polymorphic(PIC<0.25) in the three polymorp- hism locus. But the other populations were in medium polymorphic (0.25