Observations on a Transmissible Agent Determining Sexual Differentiation in Bacterium coli

作者：Will Hayes · 发表于：Microbiology · 年份：1953 · DOI：10.1099/00221287-8-1-72 · 被引用次数：170 · 研究领域：Evolution and Genetic Dynamics、Steroid Chemistry and Biochemistry、Bacterial Genetics and Biotechnology

SUMMARY: Analysis of a pair of Bacterium coli K-12 mutants which had ceased to show genetic recombination after storage, implicated mutant 58–161, which had previously behaved as a gene donor strain, as the infertile parent. Infertile 58–161 failed to display recombination when crossed with a gene acceptor strain (W-677) but was able to mate successfully with wild-type K-12 and prototrophic recombinant donor strains, i.e. it had become a gene acceptor. The terms ‘F + ’ and ‘F − ’ have been adopted (after Lederberg, Cavalli & Lederberg, 1952) to denote donor and acceptor strains respectively. Growth of either 58–161/F − or W-677/F − in mixed broth culture with 58–161/F + resulted in the conversion to F + of up to 75 % of re-isolated colonies of the initially F − strain. F − strains converted to F + by strains of dissimilar genotype showed no phenotypic alteration and, therefore, were not recombinants. Washed, mixed cultures on minimal agar yielded an F + conversion rate of only 3·6%, while 100 % recombinants were F + under the same conditions. The F + agent could be transmitted serially through F − strains and was not filterable. While F − × F − crosses were sterile, F + × F − crosses showed maximum fertility. F + × F + crosses were c. 1020 times less productive than F + × F −. The F + agent had a determining effect on the phenotype of recombinants. Thus, when the F + F − relationship was reversed in F + × F − crosses between the same pair of mutants, almost all recombinants w...