GEPHE SUMMARY Print
Gephebase Gene
Entry Status
Published
GepheID
GP00000183
Main curator
Courtier
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Other Carnivora
Trait State in Taxon B
Erinaceus spp.
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Latin Name
Common Name
carnivores
Synonyms
carnivores
Rank
order
Lineage
Show more ... uterostomia; Chordata; Craniata; Vertebrata; Gnathostomata; Teleostomi; Euteleostomi; Sarcopterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Boreoeutheria; Laurasiatheria
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B #1
Common Name
southern white-breasted hedgehog
Synonyms
southern white-breasted hedgehog; Erinaceus concolor Martin 1838
Rank
species
Lineage
Show more ... stomata; Teleostomi; Euteleostomi; Sarcopterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Boreoeutheria; Laurasiatheria; Eulipotyphla; Erinaceidae; Erinaceinae; Erinaceus
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
Taxon B #2
Common Name
western European hedgehog
Synonyms
western European hedgehog; European hedgehog; common hedgehog; Erinaceus europaeus Linnaeus, 1758; Erinaceous europaeus; Erinaceus europeus
Rank
species
Lineage
Show more ... ostomata; Teleostomi; Euteleostomi; Sarcopterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Boreoeutheria; Laurasiatheria; Insectivora; Erinaceidae; Erinaceinae; Erinaceus
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
Generic Gene Name
CHRNA1
Synonyms
ACHRA; ACHRD; CHRNA; CMS1A; CMS1B; CMS2A; FCCMS; SCCMS; CHNRA
Sequence Similarities
Belongs to the ligand-gated ion channel (TC 1.A.9) family. Acetylcholine receptor (TC 1.A.9.1) subfamily. Alpha-1/CHRNA1 sub-subfamily.
UniProtKB
Homo sapiens
GenebankID or UniProtKB
Mutation #1
Presumptive Null
No
Molecular Type
Aberration Type
SNP
SNP Coding Change
Nonsynonymous
Molecular Details of the Mutation
Trp187Arg
Experimental Evidence
Taxon A Taxon B Position
Codon - - -
Amino-acid Trp Arg 187
Authors
Drabeck DH; Dean AM; Jansa SA
Abstract
Honey badgers (Mellivora capensis) prey upon and survive bites from venomous snakes (Family: Elapidae), but the molecular basis of their venom resistance is unknown. The muscular nicotinic cholinergic receptor (nAChR), targeted by snake α-neurotoxins, has evolved in some venom-resistant mammals to no longer bind these toxins. Through phylogenetic analysis of mammalian nAChR sequences, we show that honey badgers, hedgehogs, and pigs have independently acquired functionally equivalent amino acid replacements in the toxin-binding site of this receptor. These convergent amino acid changes impede toxin binding by introducing a positively charged amino acid in place of an uncharged aromatic residue. In venom-resistant mongooses, different replacements at these same sites are glycosylated, which is thought to disrupt binding through steric effects. Thus, it appears that resistance to snake venom α-neurotoxin has evolved at least four times among mammals through two distinct biochemical mechanisms operating at the same sites on the same receptor.

Copyright © 2015 Elsevier Ltd. All rights reserved.
Additional References
Mutation #2
Presumptive Null
No
Molecular Type
Aberration Type
SNP
SNP Coding Change
Nonsynonymous
Molecular Details of the Mutation
Phe189Ile
Experimental Evidence
Taxon A Taxon B Position
Codon - - -
Amino-acid Phe Ile 189
Authors
Drabeck DH; Dean AM; Jansa SA
Abstract
Honey badgers (Mellivora capensis) prey upon and survive bites from venomous snakes (Family: Elapidae), but the molecular basis of their venom resistance is unknown. The muscular nicotinic cholinergic receptor (nAChR), targeted by snake α-neurotoxins, has evolved in some venom-resistant mammals to no longer bind these toxins. Through phylogenetic analysis of mammalian nAChR sequences, we show that honey badgers, hedgehogs, and pigs have independently acquired functionally equivalent amino acid replacements in the toxin-binding site of this receptor. These convergent amino acid changes impede toxin binding by introducing a positively charged amino acid in place of an uncharged aromatic residue. In venom-resistant mongooses, different replacements at these same sites are glycosylated, which is thought to disrupt binding through steric effects. Thus, it appears that resistance to snake venom α-neurotoxin has evolved at least four times among mammals through two distinct biochemical mechanisms operating at the same sites on the same receptor.

Copyright © 2015 Elsevier Ltd. All rights reserved.
Additional References
RELATED GEPHE
Related Genes
No matches found.
Related Haplotypes
4
COMMENTS
Parallel changes in a 3rd lineage thought to be venom resistant (pigs)
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