人类TCRαβ家族V基因的进化研究

Evolution of human T cell receptor variable gene segment families

目的:了解人类TCRα家族V基因(TCRAV)和TCRβ家族V基因(TCRBV)的进化特征。方法:采用MEGA3.1软件对人类TCRAV和TCRBV基因分别构建进化树,并估算基因复制的发生时间;采用FEL法检测TCRAV和TCRBV编码序列正选择和负选择位点。结果:进化树显示TCRAV和TCRBV的基因分组在进化过程中已经维持了相当长的时间。TCRAV已经不受正选择作用,TCRBV基因序列的CDRs区域检测到两个正选择位点。结论:人类TCRαβ家族V基因的进化特征为研究TCR基因在机体免疫及疾病防治提供了理论分析基础。

Objective：To study the phylogenies of human T cell receptor variable gene segment （TCR V） families. Methods：Phylogenetic trees for the functional TCRAV and TCRBV segment families were constructed by the MEGA computer program, with which to estimate the duplication events and to detect the positive selection and negative selection of the V segment codon by FEL method. Results： It was showed that the divergent gene groups of TCRAV and TCRBV were maintained during a long evolutionary time by the phylogenetic trees. TCRAV genes were under negative selection,but in tIER BV genes, CDRs were subject to positive selection and FRs under negative selection. Conclusion： This research provides the theoretical basis for studying the function of tIER gene in immunity and disease remedy.