title: Caste-biased gene expression in a facultatively eusocial bee suggests a role for genetic accommodation in the evolution of eusociality.
abstract: Developmental plasticity may accelerate the evolution of phenotypic novelty through genetic accommodation, but studies of genetic accommodation often lack knowledge of the ancestral state to place selected traits in an evolutionary context. A promising approach for assessing genetic accommodation involves using a comparative framework to ask whether ancestral plasticity is related to the evolution of a particular trait. Bees are an excellent group for such comparisons because caste-based societies (eusociality) have evolved multiple times independently and extant species exhibit different modes of eusociality. We measured brain and abdominal gene expression in a facultatively eusocial bee, Megalopta genalis, and assessed whether plasticity in this species is functionally linked to eusocial traits in other bee lineages. Caste-biased abdominal genes in M. genalis overlapped significantly with caste-biased genes in obligately eusocial bees. Moreover, caste-biased genes in M. genalis overlapped significantly with genes shown to be rapidly evolving in multiple studies of 10 bee species, particularly for genes in the glycolysis pathway and other genes involved in metabolism. These results provide support for the idea that eusociality can evolve via genetic accommodation, with plasticity in facultatively eusocial species like M. genalis providing a substrate for selection during the evolution of caste in obligately eusocial lineages.
authors.affiliation: Program in Ecology, Evolution, and Conservation Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA bmjones2@illinois.edu.|Smithsonian Tropical Research Institute, Panama City 20521-9100, Panama.
authors.forename: Beryl M
authors.identifier: 0000-0003-2925-0807
authors.initials: BM
authors.lastname: Jones
authors.affiliation: Smithsonian Tropical Research Institute, Panama City 20521-9100, Panama.|Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Callum J
authors.initials: CJ
authors.lastname: Kingwell
authors.affiliation: Smithsonian Tropical Research Institute, Panama City 20521-9100, Panama.
authors.forename: William T
authors.initials: WT
authors.lastname: Wcislo
authors.affiliation: Program in Ecology, Evolution, and Conservation Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.|Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.|Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.|Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Gene E
authors.initials: GE
authors.lastname: Robinson
mesh_terms: D000818:Animals; D001516:Bees / Q000235:genetics*; D001522:Behavior, Animal; D005075:Biological Evolution; D015870:Gene Expression; D017344:Genes, Insect; D010641:Phenotype; D012919:Social Behavior
keywords: eusociality; gene expression; genetic accommodation; selection; social evolution