补体成分C3的系统发生

补体系统是先天免疫系统的重要组成部分，在宿主抗感染防御过程中起着关键作用.补体成分C3（complement component 3）是补体激活途径的中心成分，其通过3条补体激活途径参与免疫监督和免疫应答过程.虽然补体成分C3的基因和蛋白已在许多不同物种中被克隆和鉴定，对其基因的结构、功能和表达也进行了很多研究，但对C3分子的演化进程目前还不清楚. 本文对近年来补体成分C3系统发生进行了分析，同时对C3的结构、作用机制和功能进行了综述.

Phylogenetic Analysis of Complement Component 3

As an important part of the innate immune system, the complement system play a key role in the process of host defense against infections. Complement component 3 (C3) is at the central node of the complement activation pathway and is linked to the three complement activation pathways for immune surveillance and immuno responses. The C3 genes have been cloned from many different species, and their coded proteins were characterized in aspects of the structure, function and gene expression regulation. This study attempted to address the molecular evolution of C3 based on phylogenetic analysis, and the structure- function relation of C3 was also discussed.