Coulson Danielle, Upton Chris
Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 3P6, Canada.
Virus Genes. 2011 Apr;42(2):171-7. doi: 10.1007/s11262-010-0560-x. Epub 2010 Dec 14.
By comparing sets of variola virus (VARV) genomes and sets of vaccinia virus (VACV) genomes, it was found that the insertion and deletion of small pieces of DNA (3-25 nucleotides) were common events among these poxviruses. Insertion events were characterized by the creation of tandem direct repeats, whereas the deletion events generally took place between two direct repeats that were separated by a few nucleotides. A number of the VARV and VACV indels clearly did not fit the expected phylogenetic tree patterns. Some of these were found to be the result of coincident events, but others, in VACV, suggest recombination among the VACV genomes. Such recombination would make the construction of phylogenetic trees problematic. The growth of VACV under artificial conditions and at high multiplicities does not select against these deletions.
通过比较天花病毒（VARV）基因组集合和痘苗病毒（VACV）基因组集合，发现小片段DNA（3 - 25个核苷酸）的插入和缺失在这些痘病毒中是常见事件。插入事件的特征是产生串联直接重复序列，而缺失事件通常发生在被几个核苷酸隔开的两个直接重复序列之间。许多VARV和VACV的插入缺失明显不符合预期的系统发育树模式。其中一些被发现是巧合事件的结果，但VACV中的其他一些事件表明VACV基因组之间发生了重组。这种重组会使系统发育树的构建产生问题。在人工条件下和高感染复数下VACV的生长并不会选择淘汰这些缺失。
