尼罗罗非鱼主要组织相容性复合体IA基因克隆与多态分析  

Gene cloning and polymorphism analysis of major histocompatibility complex( M HC) class IA gene from Oreochromis niloticus

作　　者：李同明[1] 周芬娜[1] 崔志峰[1] 季相山[1] 王慧[1] 

机构地区：[1]山东农业大学动物科技学院水产系,山东泰安271018

出　　处：《山东大学学报（理学版）》2013年第11期14-22,共9页Journal of Shandong University(Natural Science)

基　　金：山东省博士后创新基金资助项目(200703044);山东省自然科学基金资助项目(Y2008D32)

摘　　要：采用touchdown PCR和RACE技术,获得了两条尼罗罗非鱼MHC IA基因3’端的新序列,其长度均为957 bp,分别命名为orni-DAA*0101和orni-DAA*0102,其分别编码了两种新发现的等位基因亚型。两条新序列均包含666 bp的CDS区和291 bp的3’-UTR区,CDS区包含了部分多肽结合区、全部的IGC区以及跨膜区和胞质区。同源性比对显示,cDNA序列分别在388 bp和426 bp处发生了碱基转换,而其编码的氨基酸序列在第130位点存在谷氨酸与赖氨酸的差异。首次发现相对保守的IGC区也存在变异。研究结果对于揭示尼罗罗非鱼MHC IA基因的多态性及其与高抗病性的相关性有重要价值。In this study, The PCR products by rapid amplification of cDNA ends polymerase chain reaction（ RACE- PCR） and touchdown PCR from the tilapia MHC class IA gene 3＇ end were spliced and sequenced. The two 957 bp cDNA sequences were newly obtained and named orni-DAA ＊ 0101 and orni-DAA ＊ 0102, respectively. They encode two newly discovered subtypes of the alleles from tilapia MHC class IA gene. Both of the two cDNA fragments contain a 666 bp CDS region which consists of： a partial peptide-binding region, an immunoglobulin- like region, a transmem- brane region, a cytoplasmic region and with a 291 bp 3＇-UTR region. Homologous comparison shows that the cDNA sequences have two transition sites in 388 bp and 426 bp, but the amino acid sequences have only one single amino acid changed in the 130th site： the differences between Glutamic and Lysine. It is the first time to discover an amino acid variation in the relatively conservative IGC domain. The information newly obtained has an important value to reveal the relationship between high disease-resistance and polymorphism of tilapia MHC class IA gene.

关 键 词：尼罗罗非鱼 MHC IA 基因克隆 多态性 RACE 

分 类 号：Q785[生物学—分子生物学]