无脊椎动物免疫分子多态性

 一般认为，非特异性免疫分子由于胚系基因种类有限而不具备多态性.但近年来人们发现,脊椎动物γ/δ T 细胞受体、B1细胞受体、某些固有免疫成分，以及无脊椎动物的某些免疫球蛋白超家族（immunoglobulin superfamily，IgSF）分子、抗菌肽和模式识别受体（pattern recognition receptors，PRR）等同样具有较高程度的多态性.与特异性免疫分子相似，其多态性形成机制主要为基因组水平的基因重排、单核苷酸多态性、DNA 突变和 mRNA 水平的外显子可变剪接.该多态性的出现可能是无脊椎动物的一种适应性进化，其应为低等生物特异性识别和防御不同病原微生物感染的分子基础. 本文就无脊椎动物免疫分子多态性的最新研究进展及其可能的形成机制与意义进行概述.

Polymorphisms of Immune Molecules in Invertebrates

Recent studies have shown a significant degree of molecular polymorphisms in many nonspecific immune molecules, which were believed to be conserved due to the limited variance in the germline genes. The polymorphisms in γ/δ T cell receptor, B1 cell receptor and certain innate immune components have been found in vertebrates, whereas the polymorphisms in certain immunoglobulin superfamily molecules, antimicrobial peptides and pattern recognition receptors were identified in invertebrates. Similar to that was found for the specific immune molecules, the polymorphisms in non-specific immune molecules derived from gene rearrangement, single nucleotide polymorphisms, DNA mutation and alternative splicing of exons. The polymorphisms of immune molecules in invertebrates form the molecular basis to recognize and defend against different pathogens in lower organisms, and contributed in adaptive evolution. In this review, we will discuss recent progress in the polymorphism studies on the functions of invertebrate immune molecules and their possible formation mechanisms.