Study On SNP Of Goat Callipyge Gene

Ever since a long time ago, the breeding work of meat goat was quite weak and the studies on candidate gene of double muscle trait in goat fell behind extremely comparing with other livestock and poultry for society and economy factors. There were more than twenty indigenous breeds in goat, of which Liaoning cashmere goat, Inner Mongolia cashmere goat and Jining grey goat belongs to specialization breed and others belongs to common breeds generally. Nanjiang brown goat is a better meat goat breed of our country bred via a long-term selection. However, its meat performance was relatively bad comparing with Boer goat of South African. Boer goat famous for its meat breed was produced South African originally, which has many characters, such as high productivity, quick growth and development, strong antireversion force, delicious meat and high value of seeds. Especially, it is obviously the goat breed having the trait of double muscle for that the muscle is full in neck, chest, shoulder, back, waist, buttocks and four limbs. Significant effects were got with the improvement of pure-propagation and hybridization all over the country since the introduction of Boer goat in 1995, which established useful basis for further studies on the breeding work of meat goat. On the basis of these, further research and investigation of molecular biological basis of the double muscle trait in Boer goat by molecular biological method, might provide important·theoretical and practical basis to direct the breeding work in meat goat of our country.The primers were used on the basis of Callipyge gene sequences of sheep from GenBank (Accession No. AF401294). The fragment of 493bp of Callipyge gene was amplifed from 59 Boer goar individuals, of which 15 individuals were sequenced. Aligment of these sequences, a SNP of C184T was detected by the software of BioEdit 7.0. The restriction enzyme used to recognize C184T was found by Webcutter2.0 software. Then the sequences of 1019 individuals of 22 goat breeds were used to PCR amplication, including 18 indigenous breeds, 4 introduced breeds and the offsprings of Boer goat. The PCR-RFLP analysis was performed with restriction enzyme Fok I, which Callipyge genotype was detected.There was a SNP within the fragment of 493bp by sequencing. Two alleles (C and T) and three genotypes (CC, CT and IT) were obtained. There was only CC genotype existed in Liaoning cashmere goat, Chengde polled goat, Taihang mountain goat, Shannan white goat, Chengdu brown goat, Chuandong white goat, Guizhou white goat, Matou goat, Longlin goat, Saanen goat, Nubian goat and Toggenburg goat. There were CC and CT genotypes existed in Jining grey goat, Inner Mongolia cashmere goat, Jianchang black goat, Tibetan goat, Nanjiang brown goat, Yichang white goat, Duan goat, Leizhou goat and Boer goat, and IT genotype was detected only in Boer goat. The frequency of T gene and CT genotype was the highest in the population of Boer goat, which were 0.3010 and 0.2537, respectively. The frequency of T gene and CT genotype was 0.0125～0.0667 and 0.0250～0.1333 respectively in Jining grey goat, Inner Mongolia cashmere goat, Jianchang black goat, Tibetan goat, Nanjiang brown goat, Yichang white goat, Duan goat and Leizhou goat. The frequency of CC genotype was the most in 22 breed populations.It was showed that the 22 populations were all in the balance of Hardy-Weinberg by the test (P＜0.05). The analysis of the relationship of goat CLPG genotype to body weight was carried out using general linear model by SPSS (version 13.0) with 67 Boer goat and their 247 offsprings. It showed that CC genotype of paternal genotype had an effect on the individual body weight at birth, three and four month-old, the CC genotype of paternal genotype and CT genotype of maternal genotype had an effect on the individual body weight at one week-old. It was inferred that the body weight of offspring generated by hybridism of normal male goat and female goat with Callipage gene was relatively higher at different ages, on which double muscle trait was affected. Therefore, Callipyge gene might be as a candidate gene of double muscle trait in goat, and the SNP of C184T might be a moleculer marker to detect Callipyge genotype.