title: Effects of geographical heterogeneity in species interactions on the evolution of venom genes.
abstract: Geographical heterogeneity in the composition of biotic interactions can create a mosaic of selection regimes that may drive the differentiation of phenotypes that operate at the interface of these interactions. Nonetheless, little is known about effects of these geographical mosaics on the evolution of genes encoding traits associated with species interactions. Predatory marine snails of the family Conidae use venom, a cocktail of conotoxins, to capture prey. We characterized patterns of geographical variation at five conotoxin genes of a vermivorous species, Conus ebraeus, at Hawaii, Guam and American Samoa, and evaluated how these patterns of variation are associated with geographical heterogeneity in prey utilization. All populations show distinct patterns of prey utilization. Three 'highly polymorphic' conotoxin genes showed significant geographical differences in allelic frequency, and appear to be affected by different modes of selection among populations. Two genes exhibited low levels of diversity and a general lack of differentiation among populations. Levels of diversity of 'highly polymorphic' genes exhibit a positive relationship with dietary breadth. The different patterns of evolution exhibited by conotoxin genes suggest that these genes play different roles in prey capture, and that some genes are more greatly affected by differences in predator-prey interactions than others. Moreover, differences in dietary breadth appear to have a greater influence on the differentiation of venoms than differences in the species of prey.
authors: Department of Ecology and Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, MI 48109, USA Department of Statistics, University of Michigan, Ann Arbor, MI 48109, USA changdan@umich.edu.
authors: Dan
authors: D
authors: Chang
authors: Department of Ecology and Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, MI 48109, USA.
authors: Amy M
authors: AM
authors: Olenzek
authors: Department of Ecology and Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, MI 48109, USA Smithsonian Tropical Research Institute, Balboa, Ancón, Republic of Panama.
authors: Thomas F
authors: TF
authors: Duda
mesh_terms: D018948:American Samoa; D000818:Animals; D020916:Conotoxins / Q000235:genetics* / Q000378:metabolism; D052078:Conus Snail / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D005787:Gene Frequency; D014644:Genetic Variation; D005843:Geography; D006141:Guam; D006254:Hawaii; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
chemical_list: D020916:Conotoxins
keywords: Conus; conotoxin; geographical variation; predator–prey interactions; selection