Fig. 3.

Amino acid sites under positive selection in the IGF2 prohormone in matrotrophic fishes. (A) Schematic of domain structure of the IGF2 peptide sequence. (B) Schematic representation of a portion of IGF2 encompassing all amino acid sites exhibiting a >50% posterior probability (by Bayes Empirical Bayes analysis) of positive selection according to the branch-site models for both extensive matrotrophs (Table 1) and lecithotrophs (Table 3). Gray bars, sites with 50% < posterior probability < 95%; blue bars, sites with posterior probability > 95%: red bars, sites with posterior probability > 99%.