DuBose R F, Dykhuizen D E, Hartl D L
Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110.
Proc Natl Acad Sci U S A. 1988 Sep;85(18):7036-40. doi: 10.1073/pnas.85.18.7036.
An 1871-nucleotide region including the phoA gene (the structural gene encoding alkaline phosphatase, EC 3.1.3.1) was cloned and sequenced from eight naturally occurring strains of Escherichia coli. Alignment with the sequence from E. coli K-12 made apparent that there were 87 polymorphic nucleotide sites, of which 42 were informative for phylogenetic analysis. Maximum parsimony analysis revealed six equally parsimonious trees with a consistency index of 0.80. Of the 42 informative sites, 22 were inconsistent with each of the maximum parsimony trees. The spatial distribution of the inconsistent sites was highly nonrandom in a manner implying that intragenic recombination has played a major role in determining the evolutionary history of the nine alleles. The implication is that different segments of the phoA gene have different phylogenetic histories.
从八株自然存在的大肠杆菌菌株中克隆并测序了一个包含phoA基因(编码碱性磷酸酶的结构基因,EC 3.1.3.1)的1871个核苷酸区域。与大肠杆菌K-12的序列比对表明,有87个多态性核苷酸位点,其中42个对于系统发育分析具有信息性。最大简约分析揭示了六棵同等简约的树,一致性指数为0.80。在42个信息位点中,有22个与每棵最大简约树不一致。不一致位点的空间分布高度非随机,这意味着基因内重组在决定九个等位基因的进化历史中起了主要作用。这意味着phoA基因的不同片段具有不同的系统发育历史。