Study On Genetic Diversity Of Goat Agouti Gene

On the basis of sequences from GenBank, part of Agouti gene fragments was amplified. The 5275bp of goat agouti gene was obtained This part fragment of intron3 and exon4 had been handed out to GenBank, the Accession Number was DQ058664.13 point mutations were found in this fragment, of which 12 was in the intron 3 and 1 is in exon 4. These mutations were named as follows: A1796C, C1802G, C4283T, G4306T, A4312C, A4391T, A4417T, A4483C, C4578G, A4815T, C4888T, A4900G, and G5256T. The mutation G5256T lead to the amino acid substitution of V (Val) for G (Gly).For the C4888T, the gene frequency of C was mainly the same as T in most native breeds. The genetic characteristic of Tibetan, Chuandong white and Shannan white were closer, Longlin had closer genetic characteristic with Leizhou. The gene frequency of C in Taihang was 0.8030, which was the highest among these breeds. From the test of significance, the genotype of Taihang was different significantly with the other breeds.As the G5256T, allele T was the dominant gene in these breeds except for Chuandong white. The genetic characteristic of Chuandong white and Motou were different with the others. However the genetic characteristic of Guizhou White, Yichang White, Longlin and Guizhou Black were very similar. The goats from Southern China had higher polymorphisms than those from Northern.The molecular dendrogram among goat breeds was based on AIGD, 16 native goat breeds studied in this paper were divided into three groups, and the first group included Motou, Chuandong white, Longlin, Yichang White, Guizhou Black, Guizhou White, Chengde Horn Down, and Inner Mongolia Cashmere. The second group included Taihang White, Shannan White, Liaoning Cashmere, Tibetan, Leizhou, Jining Gray and Du'an. As a developed breed, Nanjiang Momgolian was in the third group.The similarity of Agouti gene sequence among goat and cattle, pig and horse were 92%, 65% and 59% correspondingly. An insert fragment was found in the sequences of cattle, pig and horse, which was 136 bp from 1842 to 1977 in the goat Agouti gene.With the group analysis to the 24 Agouti gene exon sequences from 8 species, goat had the highest similarity with cattle, and then pig, dog, cat, red fox, human and mouse in order. As the animal taxonomy, goat belongs to Bovidae Capra. The conclusion we had got here was identical with animal taxonomy.