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1: Science. 2002 Aug 23;297(5585):1336-9.Click here to read Links
Comment in:
Science. 2002 Aug 23;297(5585):1289-90.

Mechanisms of adaptation in a predator-prey arms race: TTX-resistant sodium channels.

Geffeney S, Brodie ED Jr, Ruben PC, Brodie ED 3rd.

Department of Biology, Utah State University, Logan, UT 84322, USA.

Populations of the garter snake Thamnophis sirtalis have evolved geographically variable resistance to tetrodotoxin (TTX) in a coevolutionary arms race with their toxic prey, newts of the genus Taricha. Here, we identify a physiological mechanism, the expression of TTX-resistant sodium channels in skeletal muscle, responsible for adaptive diversification in whole-animal resistance. Both individual and population differences in the ability of skeletal muscle fibers to function in the presence of TTX correlate closely with whole-animal measures of TTX resistance. Demonstration of individual variation in an essential physiological function responsible for the adaptive differences among populations is a step toward linking the selective consequences of coevolutionary interactions to geographic and phylogenetic patterns of diversity.

PMID: 12193784 [PubMed - indexed for MEDLINE]