红鲤4群体间主要组织相容性复合体的差异

应用鱼类主要组织相容性复合体(MIC)基因来探讨鱼类种群间遗传结构,寻找分子遗传标记。根据已报道的鲤鱼MICI类基因序列,设计了一对特异性引物,从兴国红鲤、荷包红鲤、玻璃红鲤及瓯江彩鲤基因组DNA中扩增了编码MICI类分子α2链的基因片段,并进行克隆、测序。结果表明,(1)编码MHC I类分子α2链的基因多态性较为丰富,234bp长度中有106个变异位点,多态位点百分率达45．3％;荷包红鲤的基因序列与其它3群体红鲤有显著差异;(2)由编码MICI类分子α2链的基因和氨基酸序列构建的系统进化树一致,兴国红鲤与团江彩鲤关系较近,属于同一进化支,玻璃红鲤和荷包红鲤分别属于另外两个不同的进化支,荷包红鲤是较为特化的群体;(3)多态性丰富的编码MICI类分子α2链的基因,适宜作为鲤鱼不同群体的分子遗传标记。

The variations of major histocompatibility complex in four populations of red common carp

The major histocompatibility complex ( MHC) of fish was used to study the genet ic structure as a molecular genetic marker of four populations of red common carp. Based on reported common carp MHC class .. gene sequences, a pair of specific primers was designed, MHC class .. molecular ..2 gene fragments were amplified from Xingguo red common carp ( Cyprinus carpio var. singguonensis ) , purse red common carp ( C. carpio var. wuyuanensis ) , glass red common carp ( C. carpio var. wananensis) , and Oujiang color common carp ( C. carpio var. color ) , then cloned and sequenced. The polymorphism of encoded MHC class ..molecular ..2 chain gene was rich, with 106 variable loci in 234bp in length. The percentage of polymorphism was 45. 3%, among the four populations, purse red common carp was significantly dif ferent from the other red common carps. The phylogenet ic trees constructed by encoded MHC class ..molecular ..2 chain gene and its amino acid sequences indicated identically, and the relationship between Xingguo red common carp and Oujiang color common carp was clo ser, belonging to one evo lutionary branch, whereas glass red common carp and purse red common carp belonged to the other two different evolutionary branches respectively. The purse red common carp is a more specialized group. The rich polymorphism of encoded MHC class .. molecular ..2 chain gene is suitable as a molecular genetic marker for different populations of common carp.