TitleParallel molecular evolution in an herbivore community.
Publication TypeJournal Article
Year of Publication2012
AuthorsZhen, Y, Aardema, ML, Medina, EM, Schumer, M, Andolfatto, P
Date Published2012 Sep 28
KeywordsAdaptation, Biological, Amino Acid Sequence, Amino Acid Substitution, Animals, Apocynaceae, Cardenolides, Evolution, Molecular, Genetic Pleiotropy, Herbivory, Host-Parasite Interactions, Insects, Molecular Sequence Data, Organ Specificity, Sodium-Potassium-Exchanging ATPase

Numerous insects have independently evolved the ability to feed on plants that produce toxic secondary compounds called cardenolides and can sequester these compounds for use in their defense. We surveyed the protein target for cardenolides, the alpha subunit of the sodium pump, Na(+),K(+)-ATPase (ATPĪ±), in 14 species that feed on cardenolide-producing plants and 15 outgroups spanning three insect orders. Despite the large number of potential targets for modulating cardenolide sensitivity, amino acid substitutions associated with host-plant specialization are highly clustered, with many parallel substitutions. Additionally, we document four independent duplications of ATPĪ± with convergent tissue-specific expression patterns. We find that unique substitutions are disproportionately associated with recent duplications relative to parallel substitutions. Together, these findings support the hypothesis that adaptation tends to take evolutionary paths that minimize negative pleiotropy.

Alternate JournalScience