荷包猪SLA-DRB基因cDNA的克隆及分子进化特征分析

The Cloning of c DNA of SLA-DRB from Hebao Pigs and the Analysis of Their Molecular Evolutionary Characteristics

旨在研究荷包猪SLA-DRB基因的分子特征,设计引物用RT-PCR扩增3头荷包猪DRB基因c DNA,并克隆至p MD18-T Vector,阳性克隆测序并做序列分析,分别进行同源性、分子进化及主要氨基酸变异位点分析。结果表明,成功从3头荷包猪中扩增得到SLA-DRB基因,分别命名为SLA-DRB-HB01-03,经序列测定后,证实c DNA全长为836 bp,其中1-801为ORF区,共编码266个氨基酸。同源性分析显示,SLA-DRB-HB与其他SLA-DRB等位基因的同源性介于90.3%-99.8%之间。分子进化分析表明,荷包猪SLA-DRB-HB独立分支,与其他等位基因相比较,进化更加原始。氨基酸变异位点和多态性分析结果显示,SLA-DRBHB本身存在一定的多态性。

In order to study the molecular characteristics of SLA-DRB derived from Hebao pigs, a pair of primers were designed to amplify the c DNA of SLA-DRB from 3 Hebao pigs. Then the amplified c DNA were cloned into p MD18-T vector and the positive clones were sequenced and analyzed by homology comparing, molecular evolution analysis, and comparing and analyzing the key amino acid sites. It was shown that the SLA-DRB alleles were amplified successfully from the tissues of the 3 Hebao pigs, and the alleles were designated as SLA-DRB-HB01, 02, and 03. After sequencing, the results showed that the c DNA of SLA-DRB-HB alleles was 836 bp, and the open reading fragments（ORF）of SLADRB-HB locating at sites of 1-801, encoding 266 amino acids. By homology analyzing, the SLA-DRB-HB genes had a homology value of 90.3%-99.8% with other SLA-DRB alleles. The analysis of molecular evolution showed that the SLA-DRB-HB alleles were clustered an independent branch of phylogenetic tree, and SLA-DRB-HB evolved more primarily in contrast to other SLA-DRB alleles. The analysis of the mutated amino acids sites and the polymorphism of SLA-DRB-HB demonstrated that they had polymorphism.