Fig. 3.

Principal Component Analysis (PCA) diagram of the complementary metabolite profiles produced through pairwise interactions (host environment). Complementary metabolites are those whose synthesis required the coexistence of both pair members and cannot be produced by either member alone in the predefined environment in which the simulations were carried out. P, C, H, R and W represent Portiera, Cardinium, Hamiltonella, Rickettsia and Wolbachia, respectively. Colors denote the species/biotype origin of each symbiont with the exception of Portiera that represents a generic origin. PCA clusters are present in colored circles adjacent to the bacterial combination initials. Hamiltonella and Cardinium combination have no synergistic metabolites and consequently is not represented. Black arrows represent determinant vectors. For plotting reasons, only names of the most important vectors are displayed (description of all synergistic metabolite and pathways is described in Additional file 8)