Published online by Cambridge University Press: 14 April 2009
Analysis of tetraparental Hfr × F− matings of Escherichia coli strains showed that mating complexes were predominantly pairs or small aggregates of cells. Many physically associated complexes of donor and recipient cells gave rise to no recombinant cells. The observed linkage of genetic markers in recombinants is sensitive to multiple mating events, and should therefore be measured under well-defined conditions giving pairwise matings only.