GEPHE SUMMARY
Gephebase Gene
Entry Status
Published
GepheID
GP00000734
Main curator
Martin
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Other fishes
Trait State in Taxon B
Takifugu rubripes
Ancestral State
Data not curated
Taxonomic Status
Taxon A
Latin Name
Common Name
teleost fishes
Synonyms
teleost fishes
Rank
infraclass
Lineage
Show more ... ular organisms; Eukaryota; Opisthokonta; Metazoa; Eumetazoa; Bilateria; Deuterostomia; Chordata; Craniata; Vertebrata; Gnathostomata; Teleostomi; Euteleostomi; Actinopterygii; Actinopteri; Neopterygii
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B
Common Name
torafugu
Synonyms
Fugu rubripes; Sphaeroides rubripes; Tetraodon rubripes; torafugu; tiger puffer; Takifugu rubripes (Temminck & Schlegel, 1850)
Rank
species
Lineage
Show more ... leosteomorpha; Neoteleostei; Eurypterygia; Ctenosquamata; Acanthomorphata; Euacanthomorphacea; Percomorphaceae; Eupercaria; Tetraodontiformes; Tetraodontoidei; Tetradontoidea; Tetraodontidae; Takifugu
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
M1240T
Experimental Evidence
Taxon A Taxon B Position
Codon - - -
Amino-acid - - -
Authors
Jost MC; Hillis DM; Lu Y; Kyle JW; Fozzard HA; Zakon HH
Abstract
Approximately 75% of vertebrate proteins belong to protein families encoded by multiple evolutionarily related genes, a pattern that emerged as a result of gene and genome duplications over the course of vertebrate evolution. In families of genes with similar or related functions, adaptation to a strong selective agent should involve multiple adaptive changes across the entire gene family. However, we know of no evolutionary studies that have explicitly addressed this point. Here, we show how 4 taxonomically diverse species of pufferfishes (Tetraodontidae) each evolved resistance to the guanidinium toxins tetrodotoxin (TTX) and saxitoxin (STX) via parallel amino acid replacements across all 8 sodium channels present in teleost fish genomes. This resulted in diverse suites of coexisting sodium channel types that all confer varying degrees of toxin resistance, yet show remarkable convergence among genes and phylogenetically diverse species. Using site-directed mutagenesis and expression of a vertebrate sodium channel, we also demonstrate that resistance to TTX/STX is enhanced up to 15-fold by single, frequently observed replacements at 2 sites that have not previously been implicated in toxin binding but show similar or identical replacements in pufferfishes and in distantly related vertebrate and nonvertebrate animals. This study presents an example of natural selection acting upon a complete gene family, repeatedly arriving at a diverse but limited number of adaptive changes within the same genome. To be maximally informative, we suggest that future studies of molecular adaptation should consider all functionally similar paralogs of the affected gene family.
Additional References
RELATED GEPHE
Related Haplotypes
1
COMMENTS
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