Fig. 8. Possible scenarios of symbiont replacements during the evolution of Adelgidae.

A Hypothesis proposed in von Dohlen et al.([15]). B Current hypothesis based on the results of this study. Two-letter codes and colored lines indicate acquisition and retention of specific symbionts. C Venn-like diagrams showing the relative contributions of each symbiont to synthesizing EAA and precursors (homoserine and chorismate). In each pair, hypothesized senior symbionts are represented by circles on the left and juniors on the right; age relationships are based on B. Numbers where circles overlap indicate EAA or precursors that symbionts cooperate to produce. In pathways where partial redundancies exist between symbionts, the symbiont contributing genes for the full pathway is counted as the sole contributor.