GEPHE SUMMARY
Entry Status
Published
GepheID
GP00000052
Main curator
Martin
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Other fishes
Trait State in Taxon B
Dissostichus mawsoni - notothenioid fishes
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
Antarctic toothfish
Synonyms
Antarctic toothfish; Dissostichus mawsoni Norman, 1937; Dissostichus mawsonii; Dissosticus mawsoni
Rank
species
Lineage
Show more ... Clupeocephala; Euteleosteomorpha; Neoteleostei; Eurypterygia; Ctenosquamata; Acanthomorphata; Euacanthomorphacea; Percomorphaceae; Eupercaria; Perciformes; Notothenioidei; Nototheniidae; Dissostichus
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
Generic Gene Name
afgp8
Synonyms
-
String
-
Sequence Similarities
-
GO - Molecular Function
-
GO - Biological Process
-
UniProtKB
Notothenia neglecta
GenebankID or UniProtKB
Presumptive Null
No
Molecular Type
Aberration Type
Molecular Details of the Mutation
multiple modifications of a pancreatic; secreted trypsinogen; notably via multiplications of small tri-peptidic repeats
Experimental Evidence
Authors
Chen L; DeVries AL; Cheng CH
Abstract
Freezing avoidance conferred by different types of antifreeze proteins in various polar and subpolar fishes represents a remarkable example of cold adaptation, but how these unique proteins arose is unknown. We have found that the antifreeze glycoproteins (AFGPs) of the predominant Antarctic fish taxon, the notothenioids, evolved from a pancreatic trypsinogen. We have determined the likely evolutionary process by which this occurred through characterization and analyses of notothenioid AFGP and trypsinogen genes. The primordial AFGP gene apparently arose through recruitment of the 5' and 3' ends of an ancestral trypsinogen gene, which provided the secretory signal and the 3' untranslated region, respectively, plus de novo amplification of a 9-nt Thr-Ala-Ala coding element from the trypsinogen progenitor to create a new protein coding region for the repetitive tripeptide backbone of the antifreeze protein. The small sequence divergence (4-7%) between notothenioid AFGP and trypsinogen genes indicates that the transformation of the proteinase gene into the novel ice-binding protein gene occurred quite recently, about 5-14 million years ago (mya), which is highly consistent with the estimated times of the freezing of the Antarctic Ocean at 10-14 mya, and of the main phyletic divergence of the AFGP-bearing notothenioid families at 7-15 mya. The notothenioid trypsinogen to AFGP conversion is the first clear example of how an old protein gene spawned a new gene for an entirely new protein with a new function. It also represents a rare instance in which protein evolution, organismal adaptation, and environmental conditions can be linked directly.
RELATED GEPHE
Related Genes
Related Haplotypes
No matches found.
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