合作小型猪T细胞受体α链的基因结构及其多样性-中国动物学报.DOCVIP

PAGE PAGE 10 合作小型猪T细胞受体α链的基因结构及其多样性研究 高建平1,2，李玩生1，曾爽1，房永祥1，冯海燕1，杨孝朴2，景志忠*1,2 （1.中国农业科学院兰州兽医研究所　家畜疫病病原生物学国家重点实验室，农业部兽医公共卫生重点实验室，甘肃 兰州 730046；2. 甘肃农业大学动物医学院,甘肃 兰州 730070） 摘要：为了探讨猪TCR基因分子结构的复杂性及与人类的相似性，以公开的猪TCRα链基因为参考序列设计2对特异性引物，用RT－PCR法从合作小型猪外周血、淋巴结和脾脏的淋巴细胞中克隆了93个猪TCRα基因（简称STA）。测序分析表明，克隆的猪TCRα链的基因均含有可变的信号肽区和V区、高变的J区和恒定的C区的基因片段，但基因间的核苷酸序列组成都不完全相同，且具有十分复杂的多态性和多样性，基因间的同源性在68.4%～98.7%，这与TCRα链的基本基因结构特征相一致。依据TCRα基因的同源性对其分子结构、遗传演化关系和归类发现分析，在其信号肽区、FR1区和CDR1区、FR2区 和CDR2区以及FR3区和CDR3区都存在一些变异集中点和变异热点区。用IMGT/V-QUEST分析方法可将合作小型猪TCRαV区（STAV）、J区(STAJ)基因片段与人类的进行比较分析，发现合作小型猪TCRα与人类的遗传演化关系较近，每个序列都能找到与人类对应的TRAV、TRAJ基因片段，甚至V区的相似性可达92%以上。这表明，近交培育的合作小型猪在正常状态具有应对外界复杂微生物等环境的TCR遗传多样性分子基础，且适合作为人类免疫学及疾病研究的动物模型。 关键词：合作小型猪；TCRα基因;生物信息学;多样性； Genetic structure and diversity of T cell receptor alpha chain genes in Hezuo minipig GAO Jian-ping1,2，LI Wan-sheng1，ZENG Shuang1，FANG Yong-xiang 1，FENG Hai-yan 1， YANG Xiao-pu 2，JING Zhi-zhong *1,2 (1.State Key Laboratory of Veterinary Etiological Biology/Key Laboratory of Veterinary Public health of Ministry of Agriculture/Lanzhou Veterinary Research Institute, CAAS, Lanzhou 730046, China. 2. College of Veterinary Medine, Gansu Agricultural University, Lanzhou 7300 Abstract: Based on the gene of porcine T cell receptor alpha chain(TCRα) from the GenBank database, 93 of swine T cell receptor alpha chain genes(STA) were cloned by reverse transcription-polymerase chain reaction (RT-PCR) from porcine lymphocyte of peripheral-blood, lymphoid node and spleen. Sequence analysis showed that STA genes were all contain a domain of variable signal peptide and V, hypervariable J and conservative C. however, nucleotide sequence of STA was not complete identical with only 68.4%～98.7% homology among genes, and had extremely sophisticated polymorphism and diversity. This was concord to the genetic structure of TCRα chain. Molecular structure, genetic evolution and classify of these genes were carried out according to the homology of TCRα gene, which all exist several site