Chemoreceptor Evolution in Hymenoptera and Its Implications for the Evolution of Eusociality.
Eusocial insects, mostly Hymenoptera, have evolved unique colonial lifestyles that rely on the perception of social context mainly through pheromones, and chemoreceptors are hypothesized to have played important adaptive roles in the evolution of sociality. However, because chemoreceptor repertoires have been characterized in few social insects and their solitary relatives, a comprehensive examination of this hypothesis has not been possible. Here, we annotate ∼3,000 odorant and gustatory receptors in recently sequenced Hymenoptera genomes and systematically compare >4,000 chemoreceptors from 13 hymenopterans, representing one solitary lineage (wasps) and three independently evolved eusocial lineages (ants and two bees). We observe a strong general tendency for chemoreceptors to expand in Hymenoptera, whereas the specifics of gene gains/losses are highly diverse between lineages. We also find more frequent positive selection on chemoreceptors in a facultative eusocial bee and in the common ancestor of ants compared with solitary wasps. Our results suggest that the frequent expansions of chemoreceptors have facilitated the transition to eusociality. Divergent expression patterns of odorant receptors between honeybee and ants further indicate differential roles of chemoreceptors in parallel trajectories of social evolution.
Department of Biological Sciences, Vanderbilt University.
Xiaofan
X
Zhou
Department of Biological Sciences, Vanderbilt University.
Antonis
A
Rokas
Department of Cell and Developmental Biology, University of Pennsylvania Department of Genetics, University of Pennsylvania Department of Biology, University of Pennsylvania.
Shelley L
SL
Berger
School of Life Sciences, Arizona State University, Tempe.
Jürgen
J
Liebig
Department of Entomology, University of California, Riverside.
Anandasankar
A
Ray
Department of Biological Sciences, Vanderbilt University l.zwiebel@vanderbilt.edu.
Laurence J
LJ
Zwiebel
D000818:Animals; D001000:Ants / Q000235:genetics / Q000378:metabolism; D001516:Bees / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D015870:Gene Expression; D023281:Genomics; D006927:Hymenoptera / Q000145:classification / Q000235:genetics*; D058977:Molecular Sequence Annotation; D018035:Receptors, Odorant / Q000235:genetics* / Q000378:metabolism; D012919:Social Behavior; D013649:Taste
D018035:Receptors, Odorant
Hymenoptera; chemosensation; eusociality; gustatory receptor; odorant receptor