Ecological release and venom evolution of a predatory marine snail at Easter Island.
BACKGROUND
Ecological release is coupled with adaptive radiation and ecological diversification yet little is known about the molecular basis of phenotypic changes associated with this phenomenon. The venomous, predatory marine gastropod Conus miliaris has undergone ecological release and exhibits increased dietary breadth at Easter Island.


RESULTS
We examined the extent of genetic differentiation of two genes expressed in the venom of C. miliaris among samples from Easter Island, American Samoa and Guam. The population from Easter Island exhibits unique frequencies of alleles that encode distinct peptides at both loci. Levels of divergence at these loci exceed observed levels of divergence observed at a mitochondrial gene region at Easter Island.


CONCLUSIONS
Patterns of genetic variation at two genes expressed in the venom of this C. miliaris suggest that selection has operated at these genes and contributed to the divergence of venom composition at Easter Island. These results show that ecological release is associated with strong selection pressures that promote the evolution of new phenotypes.
Duda
Thomas F
TF
Department of Ecology and Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, Michigan, USA. tfduda@umich.edu
Lee
Taehwan
T
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D020916:Conotoxins / Q000737:chemistry / Q000235:genetics*; D052078:Conus Snail / Q000235:genetics*; D004463:Ecology; D003576:Electron Transport Complex IV / Q000235:genetics; D019143:Evolution, Molecular; D005243:Feces; D014644:Genetic Variation; D005843:Geography; D006239:Haplotypes; D008969:Molecular Sequence Data; D011235:Predatory Behavior; D012623:Seawater; D020539:Sequence Analysis, Protein
D020916:Conotoxins; D003576:Electron Transport Complex IV