鱼类免疫球蛋白分子生物学研究进展

Progression of Current Knowledge on Molecular Biology in Fish Immunoglobulin

综述了近年来鱼类免疫球蛋白分子生物学的最新研究进展,主要涉及鱼类Ig基因序列分析、组成形式、重排机制以及转录调控4个方面.鱼类Ig重链和轻链基因克隆分析证实有多种不同的重链、轻链类型存在;重链和轻链基因由不同染色体上的多基因座编码,在不同的鱼类中具有不同的基因组织形式;重组信号序列在重链、轻链基因组中均有发现,其重排过程主要由重组活化酶进行调控;增强子和启动子在鱼类Ig转录调控中发挥重要作用,其中增强子序列在系统发育中具有保守性.Ig作为鱼体特异性体液免疫应答的主要因子,其分子生物学的深入研究对于阐明脊椎动物免疫系统进化具有重要意义.

The current knowledge during the past few years concerning the sequence analysis,structure,organization and translation regulation of immunoglobulin genes in fish was presented.Different types of immunoglobulin heavy chain and light chain had been identified in fish.The heavy chain and light chain of the immunoglobulin were encoded by multigenic loci on separate chromosomes.In different fish,the Ig genes were organized in different patterns.Recombination signal sequences（RSS）identified in both the heavy chain and the light chain genes were recognized and regulated by he recombination activating enzyme during the process of gene organization.The enhancer and the promoter played an important role in the translation regulation of immunoglobulin genes in fish.The sequences of the promoter were conserved in bony fish phylogeny.Since the immunoglobulin played a very important role in the specific humoral immune response in fish,the better understanding of the molecule mechanism of immunoglobulin was now thought to be of key importance for the clarification about the immune system evolution in the vertebrates.