摘要
随着DNA聚合酶X家族成员数量的增加 ,特别是两个昆虫痘病毒 (entomopoxvirus ,EPV)成员的加入 ,家族内部的系统发育关系需要重新检查。总共 37个来自不同物种的DNA聚合酶X家族成员的核心结构域序列被分析。结果显示 :系统发育树呈现的家族内部系统发育关系基本上与家族成员的物种分布状态相吻合 ,其中 ,病毒成员与真核生物DNA聚合酶beta(polβ)亚群构成姐妹群 ,提示病毒成员可能起源于真核细胞的相应基因。亚群的歧异时间、基因结构比较和同线基因保守性分析显示 ,哺乳动物DNA聚合酶基因 (PolM)可能起源于脱氧核苷酸末端转移酶基因 (TdT)最近发生的基因重复。
Phylogeny within DNA polymerase X family requires a re examination as the expansion of family members,particularly considering the enter of two entomopoxvirus(EPV) members.A total of 37 DNA polymerase core domain sequences(SMART domain),which come from numerous species with different evolutional levels,including above two virus members,were analyzed.The result showed that,the phylogenetic relationship within this family basically assorted with the distribution status of used species,of which two virus members and DNA polymerase beta(polβ) of eukaryote were clustered together into sister group,indicating the likelihood that the two entomopoxviruses originated from eukaryote.The divergence time of subgroups,similarity of gene structure and conservation of syntenic genes were also analyzed,and evidences showed that,DNA polymerase mu (polμ) is only present in Mammals,and as a recently occured duplication gene of terminal deoxynucleotidyl transferase(TdT).
