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How small can the difference among competitors be for coexistence to occur
Author(s) -
Kashiwagi Akiko,
Kanaya Tadashi,
Yomo Tetsuya,
Urabe Itaru
Publication year - 1998
Publication title -
population ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 59
eISSN - 1438-390X
pISSN - 1438-3896
DOI - 10.1007/bf02763407
Subject(s) - biology , chemostat , plasmid , genetics , point mutation , strain (injury) , population , competitor analysis , escherichia coli , nucleotide , gene , mutation , evolutionary biology , bacteria , demography , management , anatomy , sociology , economics
Closely related competitors comprising of Escherichia coli strains having the same metabolic system and differing only with a few bases on the glutamine synthetase gene in the plasmid pKGN were previously shown to coexist in a chemostat. The differences among these closely related competitors can be considered large enough to allow coexistence as the level of enzyme activity is different. To bring the difference among competitors to the slightest possible, the mutation was introduced on the noncoding region of the plasmid pKGN harbored in the wild‐type strain (strain W). The new strain, strain W’, carries the plasmid pKGN’ with a 4‐base insertion at the Hind III site in the polycloning site of pKGN. As the noncoding region is a nucleotide segment that is not translated into amino acids, the relatedness between strains W and W’ is the closest possible from the genetic point of view. Interestingly, though both strains are almost identical, they can coexist stably in a chemostat irrespective of the initial population size. These experimental results suggest that in the natural ecosystem, no matter how akin competitors are, coexistence is not impossible.