Phylogenetic Relationships Between Mycoplasmas and Other Procaryotes Based upon the Electrophoretic Behavior of Their Ribosomal Ribonucleic Acids

Abstract
The migration of ribosomal ribonucleic acids (rRNA's) from bacteria, bacterial L forms, mycoplasmas, and acholeplasmas in nondenaturing and formamide gels has been examined. Mycoplasmal and acholeplasmal RNAs migrate in a pattern distinct from each other and from bacteria in nondenaturing gels. The differences observed appear to be mainly due to conformational differences in the molecules. When examined under denaturing conditions in formamide gels, the 23S RNAs of all organisms examined comigrated. The 16S RNAs of mycoplasmas and acholeplasmas comigrated and appear to be of a smaller molecular weight than bacterial 16S RNA. It is suggested that the differences observed are indicative of significant phylogenetic divergence between mycoplasmas and bacteria or bacterial L forms.