Principal Component Analysis of genes involved in HCH degradation pathway. (A) PCA individual factor plot showing the grouping of the nine Sphingobium strains based upon the sequence divergence and copy number of the set of lin genes. Principle components 1 (accounting for 30.87% of the variation of the strains) and 2 (14.47%) were chosen as the separation of the strains by these PCs demonstrated the highest fidelity to known HCH degradation ability. (B) PCA variable factor plot using principle component 1 and 2, showing the contribution of the lin genetic sequences (s.linA, s.linB…) and copy number (c.linA, c.linB…) to the variation of the nine Sphingobium strains. HCH degradation ability was plotted as a supplementary categorical variable (not factored into the PCs), with non-HCH degraders coded as 0, partial degraders as 1, and complete degraders as 2.