AN APPROACH TO THE MEASUREMENT OF GENETIC RELATEDNESS AMONG ORGANISMS

Abstract
By study of the binding of messenger RNA or DNA fragments to homologous and heterologous DNA immobilized in a gel structure, it is possible to measure quantitatively the genetic relatedness of several strains of enterobacteria. Essentially similar results are obtained from the RNA and DNA experiments. Reciprocal reactions in which the DNAs of the two organisms are interchanged give the same estimate of similarity. In the reaction of E. coli mes-senger RNA with the parent DNA, related RNA molecules originating from other organisms compete for the same sites in the DNA. Applications to the study of evolutionary relationships among bacteria and other organisms are considered.