RECOMBINATION IN ESCHERICHIA-COLI AND THE DEFINITION OF BIOLOGICAL SPECIES
RECOMBINATION IN ESCHERICHIA-COLI AND THE DEFINITION OF BIOLOGICAL SPECIES
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DOI：
10.1128/jb.173.22.7257-7268.1991
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发表时间：
1991-11-01
影响因子：
3.2
通讯作者：
GREEN, L
中科院分区：
文献类型：
--
作者：
DYKHUIZEN, DE;GREEN, L
测定了8种大肠杆菌野生株和鼠伤寒沙门氏菌gnd（6-磷酸葡萄糖酸脱氢酶）基因部分的DNA序列。 由于trp（色氨酸）操纵子和phoA（碱性磷酸酶）基因的一个区域已经从相同的菌株中测序，因此确定并比较了这三个区域的基因树。 基因树与物种或品系树的不同之处在于，基因树源自特定的DNA片段，而物种或品系树应该源自许多这样的片段，并且是最能代表物种或品系的系统发育关系的树。 如果E.在大肠杆菌中，不同基因的基因树与菌株树或彼此之间没有统计学差异。 但是，如果基因树有显著的不同，那么一定有重组。 方法提出，这些基因树是统计上不同的。 由于基因树的不同，我们得出结论，重组是重要的，在自然群体的E。杆菌 最后，我们建议，基因树可以用来创建一个可操作的手段，通过使用生物物种的定义来定义细菌物种。
The DNA sequence of part of the gnd (6-phosphogluconate dehydrogenase) gene was determined for eight wild strains of Escherichia coli and for Salmonella typhimurium. Since a region of the trp (tryptophan) operon and the phoA (alkaline phosphatase) gene have been sequenced from the same strains, the gene trees for these three regions were determined and compared. Gene trees are different from species or strain trees in that a gene tree is derived from a particular segment of DNA, whereas a species or strain tree should be derived from many such segments and is the tree that best represents the phylogenetic relationship of the species or strains. If there were no recombination in E. coli, the gene trees for different genes would not be statistically different from the strain tree or from each other. But, if the gene trees are significantly different, there must have been recombination. Methods are proposed that show these gene trees to be statistically different. Since the gene trees are different, we conclude that recombination is important in natural populations of E. coli. Finally, we suggest that gene trees can be used to create an operational means of defining bacterial species by using the biological species definition.