SARS冠状病毒的系统发育基因组研究

对SARS冠状病毒(SARS Coronavirus,SARS-CoV)进行了系统发育基因组研究.应用CLUSAL-X1.83程序,将来自GenBank数据库的全部102条SARS-CoV全基因组序列记录做多序列联配,然后采用MEGA3软件包进行系统发育基因组分析,使用邻接法构建系统发育树.根据该系统树,SARS-CoV全基因组记录可以分为2类.第1类包括2个来源于动物的分离株;第2类则覆盖了所有的人源分离株,并且可进一步分为2组,其中第1组包括5个来自于广东省的分离株,而第2组则覆盖了其他的来自于香港、内地和海外的分离株.这一分支格局代表了SARS-CoV从兽到人、从广东到全球的传播过程,并且基因组的替代变异幅度在传播过程中由大到小,逐渐稳定下来.还详细地给出了区分上述2群和2组的分子标签,为新毒株的鉴定和分型提供了理论依据.

PHYLOGENOMICS STUDY OF SARS CORONAVIRUS

A phylogenomics study on SARS Coronavirus (SARS-CoV) is performed. A total of 102 SARS-CoV complete genome sequence records are compiled from GenBank. Multiple sequences alignment is conducted using the program CLUSAL-X1.83, and the NJ method implemented in the MEGA3 software is employed to reconstruct the phylogenetic tree. According to the tree, all the records can be divided into two groups. The first includes two strains isolated from animals, while the second, including two sections, contains all the strains isolated from human. One section composes of five strains isolated from Guangdong Province of China, and another comprises all the remaining strains isolated from HongKong, China mainland and overseas. This branching pattern represents the transmission process of SARS-CoV from animal to human and from Guangdong to other places. In addition, the amount of substitution decreases to a stable state during the transmission process. Based on the classification, the molecular signatures which distinguish the two groups and two sections described above are given in detail, which are theoretical bases for identifying and classifying new strains.