Use of principal component analysis in interpretation of deoxyribonucleic acid relatedness

Principal component analysis of published DNA-relatedness data showed the usefulness of this method in displaying relationships among closely related bacteria, and the level of ΔTm within groups and between groups should help decide whether these groups are genospecies.

Abstract

Principal component analysis (PCA) of published DNA-relatedness data showed the usefulness of this method in displaying relationships among closely related bacteria. Very similar ordinations were obtained when relative binding ratios (RBR) at 60°C or 75°C or ΔT m values were used to form the data matrix. A curvilinear relationship and a (quasi) linear relationship were found, respectively, between 75°C and 60°C RBR and ΔT m and 60°C RBR. These statistical relationships explain the similarity of PCA results using either measurement (60°C RBR, 75°C RBR, or ΔT m). Use of PCA is suggested to delineate groups within a complex set of DNA-relatedness data. The level of ΔT m within groups and between groups should help decide whether these groups are genospecies.