GEPHE SUMMARY
Gephebase Gene
Entry Status
Published
GepheID
GP00000729
Main curator
Martin
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Amphiesma vibakari
Trait State in Taxon B
Amphiesma pryeri
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Common Name
Japanese keelback
Synonyms
Amphiesma vibakari; Tropidonotus vibakari; Japanese keelback; Amphiesma vibakari (Boie, 1826)
Rank
species
Lineage
Show more ... copterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Sauropsida; Sauria; Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera; Serpentes; Colubroidea; Colubridae; Natricinae; Hebius
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B
Latin Name
Common Name
Pryer's keelback
Synonyms
Amphiesma pryeri; Tropidonotus pryeri; Pryer's keelback; Amphiesma pryeri (Boulenger, 1887)
Rank
species
Lineage
Show more ... copterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Sauropsida; Sauria; Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera; Serpentes; Colubroidea; Colubridae; Natricinae; Hebius
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
Presumptive Null
No
Molecular Type
Aberration Type
SNP
SNP Coding Change
Nonsynonymous
Molecular Details of the Mutation
D1227E = D945E in DIII domain
Experimental Evidence
Taxon A Taxon B Position
Codon - - -
Amino-acid - - -
Authors
Feldman CR; Brodie ED; Brodie ED; Pfrender ME
Abstract
Natural selection often produces convergent changes in unrelated lineages, but the degree to which such adaptations occur via predictable genetic paths is unknown. If only a limited subset of possible mutations is fixed in independent lineages, then it is clear that constraint in the production or function of molecular variants is an important determinant of adaptation. We demonstrate remarkably constrained convergence during the evolution of resistance to the lethal poison, tetrodotoxin, in six snake species representing three distinct lineages from around the globe. Resistance-conferring amino acid substitutions in a voltage-gated sodium channel, Na(v)1.4, are clustered in only two regions of the protein, and a majority of the replacements are confined to the same three positions. The observed changes represent only a small fraction of the experimentally validated mutations known to increase Na(v)1.4 resistance to tetrodotoxin. These results suggest that constraints resulting from functional tradeoffs between ion channel function and toxin resistance led to predictable patterns of evolutionary convergence at the molecular level. Our data are consistent with theoretical predictions and recent microcosm work that suggest a predictable path is followed during an adaptive walk along a mutational landscape, and that natural selection may be frequently constrained to produce similar genetic outcomes even when operating on independent lineages.
RELATED GEPHE
Related Genes
No matches found.
Related Haplotypes
No matches found.
COMMENTS
Non-null mutation. Extreme TTX resistance evolved 5 times in Nav1.4 channel; but only in lineages that had previously evolved resistance in paralogous NaV channels
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