Riley M, Anilionis A
J Bacteriol. 1980 Jul;143(1):366-76. doi: 10.1128/jb.143.1.366-376.1980.
We have assessed the degree of relatedness of several portions of the Escherichia coli genome to the corresponding portions of the genomes of representative enteric bacteria, using the Southern transfer and hybridization technique (E. Southern, J. Mol. Biol. 98:503-517, 1975). The degree of relatedness varied among the regions examined. Judging both by the relative amounts of deoxyribonucleic acid in the various enteric genomes that are highly homologous and by the conservation of positions of restriction enzyme cleavage sites in these regions, the enteric genomes have diverged to greater extents in some parts of the genomes than in others. Portions of the genomes (including the tnaA and thyA genes, the trp operon, and one other unassigned segment) appear to have evolved in concert with the genome as a whole. By contrast, the lacZ gene and portions of the genome that are homologous to phage lambda vary more widely, perhaps reflecting a separate evolutionary origin for these segments of deoxyribonucleic acid.
我们运用Southern转移和杂交技术（E. Southern，《分子生物学杂志》98:503 - 517，1975年），评估了大肠杆菌基因组的几个部分与代表性肠道细菌基因组相应部分的相关性程度。在所检测的区域中，相关性程度各不相同。从高度同源的各种肠道基因组中脱氧核糖核酸的相对含量以及这些区域中限制性内切酶切割位点位置的保守性来判断，肠道基因组在基因组的某些部分比其他部分分化程度更大。基因组的一些部分（包括tnaA和thyA基因、trp操纵子以及另一个未指定的片段）似乎与整个基因组协同进化。相比之下，lacZ基因以及与噬菌体λ同源的基因组部分变化更为广泛，这可能反映了这些脱氧核糖核酸片段有独立的进化起源。
