猪MHC-Ⅱ类区DQA新等位基因及新突变位点的发现  

Characterization of Novel Alleles and New Mutation Sites of Porcine MHC Class Ⅱ DQA

作　　者：刘榜[1] 朱正茂[1] 余梅[1] 曹建华[1] 林丽[1] 熊统安[1] 朱猛进[1] 彭中镇[1] 李奎[1] 

机构地区：[1]华中农业大学动物科技学院动物分子生物学与育种实验室,武汉430070

出　　处：《Acta Genetica Sinica》2003年第10期955-960,共6页

基　　金：国家重点基础研究发展规划项目 (G2 0 0 0 0 1610 3 ) ;国家 863计划 (2 0 0 1AA2 2 2 2 41;2 0 0 1AA2 13 0 61);国家杰出青年基金 (3 992 5 0 2 7);教育部重点项目 (0 112 1);湖北省攻关 (2 0 0 2AA2 0 1C2 7)资助项目~~

摘　　要：根据猪SLA DQA基因cDNA序列和人HLA DQA基因组序列设计引物 ,在猪中成功扩增了一个 731bp的片段 ,该片段包括猪SLA DQA基因的大部分第 2外显子、完整第 2内含子和少部分第 3外显子 ,通过克隆和PCR直接测序获得该片段的核苷酸序列。在家系中对第 2外显子的核苷酸序列和其编码的α1 结构域的氨基酸序列进行了分析 ,并与GenBank中所有的SLA DQA第 2外显子序列进行比较分析 ,发现有 4个新突变位点和两个新等位基因存在。新等位基因分别是DQA SLT 2 6和DQA TC 2 1 1。DQA SLT 2 6与单倍型c、d相比有 8个核苷酸的差异和 4个氨基酸的改变 :单倍型c、d在 6 0、6 5、81、93位的氨基酸分别是Val、Lys、Asp、Lys;而DQA SLT 2 6相应的氨基酸是Ala、Glu、Gly、Ile。DQA TC 2 1 1与单倍型c、d相比存在 1个氨基酸的改变 ,由单倍型c和d中 94位氨基酸His变为Tyr。The primers,DQAp161 and DQAp443,were designed bas ed on the homologous region of SLA-DQA cDNA sequences and HLA-DQA genomi c sequences.The 731 bp fragment of SLA-DQA including completed intron 2,the near completed exon 2 and partial exon 3 was obtained by PCR.The nucleotide se quences of the fragment of SLA-DQA were obtained with cloning and direct s equencing.Both nucleotide sequences of exon 2 and amino acid sequences of α 1 domain were analyzed in a pedigree.The sequence data were compared with all seq uences of SLA-DQA exon 2 in GenBank.Two novel alleles,DQA-SL T 26 and DQA-TC 21-1,were found according to the above analy ses.Four amino acid changes were observed among SLA-DQA haplotype c,d and DQA-SLT 26.They were Val→Ala(60),Lys→Glu(65),Asp →Gly(81) and Lys→Ile(93).Comparing the amino acids sequence of the all SLA- DQA sequences with DQA-TC 21-1 revealed that the His (94) was changed into Tyr.

关 键 词：SLA-DQA 第2外显子 第2内含子 DNA序列 新等位基因 

分 类 号：S828[农业科学—畜牧学]