The evolutionary origins of beneficial alleles during the repeated adaptation of garter snakes to deadly prey.

ABSTRACT: Where do the genetic variants underlying adaptive change come from? Are currently adaptive alleles recruited by selection from standing genetic variation within populations, moved through introgression from other populations, or do they arise as novel mutations? Here, we examine the molecular basis of repeated adaptation to the toxin of deadly prey in 3 species of garter snakes (Thamnophis) to determine whether adaptation has evolved through novel mutations, sieving of existing variation, or transmission of beneficial alleles across species. Functional amino acid substitutions in the skeletal muscle sodium channel (Na(v)1.4) are largely responsible for the physiological resistance of garter snakes to tetrodotoxin found in their newt (Taricha) prey. Phylogenetic analyses reject the hypothes

SUBMITTER: Feldman CR 

PROVIDER: S-EPMC2726340 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature