鱼类免疫球蛋白基因结构及抗体多样性的遗传机制

本文对鱼类免疫球蛋白的基因结构以及抗体多样性产生的遗传机制作一综述。免疫球蛋白重链和轻链是由不同染色体上的多基因座编码的，在鱼类的不同分类单元中具有不同的基因组织方式。鱼类抗体可以识别外界为数众多的抗原，其多样性主要是由以下遗传机制产生的：种系V区编码区段的多样性、V (D) J区段组合的多样性、基因重组的不精确性、基因转换、体细胞突变以及H和L链的随机组合等。 Gene Structure and Genetic Diversity of Immunoglobulins in Fish ZHANG Yong-an,NIE Pin,ZHU Zuo-yan State Key Laboratory of Freshwater Ecology and Biotechnology,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China Abstract:The current knowledge concerning the structure of fish immunoglobulin (Ig) genes and the genetic mechanisms in generating fish antibody diversities is reviewed.The heavy (H-) and light (L-) chains of the immunoglobulin are encoded by multigenic loci on separate chromosomes.In different taxa of fish,the Ig genes are organized in different patterns.Fish antibody can recognize various foreign antigens,and the antibody diversity is generated by the following genetic mechanisms:the sequence diversity within the segments encoding the variable domain,the combinatorial diversity of V (D) J segments,the imprecision of rearrangements,gene conversion,somatic hypermutation,and the combination of H- and L-chain. Key words：immunoglobulin; gene; antibody; diversity; fish

Gene Structure and Genetic Diversity of Immunoglobulins in Fish

The current knowledge concerning the structure of fish immunoglobulin (Ig) genes and the genetic mechanisms in generating fish antibody diversities is reviewed. The heavy (H-) and light (L-) chains of the immunoglobulin are encoded by multigenic loci on separate chromosomes. In different taxa of fish,the Ig genes are organized in different patterns. Fish antibody can recognize various foreign antigens, and the antibody diversity is generated by the following genetic mechanisms: the sequence diversity within the segments encoding the variable domain,the combinatorial diversity of V (D) J segments, the imprecision of rearrangements,gene conversion,somatic hypermutation,and the combination of H- and L-chain.