GEPHE SUMMARY
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Gephebase Gene
Entry Status
Published
GepheID
GP00002372
Main curator
Santos
PHENOTYPIC CHANGE
Trait Category
Trait
Trait State in Taxon A
WT
Trait State in Taxon B
reduction of melanic pigmentation having pale orange-red skin but with red-wine-colored eyes
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Latin Name
Common Name
Japanese medaka
Synonyms
Poecilia latipes; Japanese medaka; Japanese rice fish; medaka; Oryzias latipes (Temminck & Schlegel, 1846); Poecilia latipes Temminck & Schlegel, 1846; Orizias latipes
Rank
species
Lineage
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ha; Neoteleostei; Eurypterygia; Ctenosquamata; Acanthomorphata; Euacanthomorphacea; Percomorphaceae; Ovalentaria; Atherinomorphae; Beloniformes; Adrianichthyoidei; Adrianichthyidae; Oryziinae; Oryzias
Parent
NCBI Taxonomy ID
is Taxon A an Infraspecies?
Yes
Taxon A Description
WT strain
Taxon B
Latin Name
Common Name
Japanese medaka
Synonyms
Poecilia latipes; Japanese medaka; Japanese rice fish; medaka; Oryzias latipes (Temminck & Schlegel, 1846); Poecilia latipes Temminck & Schlegel, 1846; Orizias latipes
Rank
species
Lineage
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ha; Neoteleostei; Eurypterygia; Ctenosquamata; Acanthomorphata; Euacanthomorphacea; Percomorphaceae; Ovalentaria; Atherinomorphae; Beloniformes; Adrianichthyoidei; Adrianichthyidae; Oryziinae; Oryzias
Parent
NCBI Taxonomy ID
is Taxon B an Infraspecies?
Yes
Taxon B Description
genotype i4/i4
GENOTYPIC CHANGE
Generic Gene Name
Tyr
Synonyms
c; Oca1; skc35; albino
String
Sequence Similarities
Belongs to the tyrosinase family.
GO - Molecular Function
GO:0042803 : protein homodimerization activity
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GO - Biological Process
GO:0042438 : melanin biosynthetic process
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GO - Cellular Component
GO:0016021 : integral component of membrane
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Presumptive Null
Molecular Type
Aberration Type
Insertion Size
1-10 kb
Molecular Details of the Mutation
"i4 allele was found to contain a 4.7- kb transposable element in the 5th exon"
"Tyr-i4 contains a 4.7-kb insertion in exon 5 (Fig. 3). If the inserted fragment was transcribed, the amino acid sequence would be altered after the 469th residue, with a termination codon (UAG) at amino acid position 471. The i4/i4 genotype exhibits a quasi-albino phenotype. This may be explained by generation of a tyrosinase protein that only lacks its C-terminus region. The wild-type tyrosinase has a highly hydrophobic amino acid block at its C terminus (aa 480 - aa 500) which is thought to be part of a membrane spanning domain (Inagaki et al., 1994). A possible explanation is that the mutant tyrosinase encoded by Tyr- i4 lacks this region, so that it cannot be positioned properly on the membrane"
"Tyr-i4 contains a 4.7-kb insertion in exon 5 (Fig. 3). If the inserted fragment was transcribed, the amino acid sequence would be altered after the 469th residue, with a termination codon (UAG) at amino acid position 471. The i4/i4 genotype exhibits a quasi-albino phenotype. This may be explained by generation of a tyrosinase protein that only lacks its C-terminus region. The wild-type tyrosinase has a highly hydrophobic amino acid block at its C terminus (aa 480 - aa 500) which is thought to be part of a membrane spanning domain (Inagaki et al., 1994). A possible explanation is that the mutant tyrosinase encoded by Tyr- i4 lacks this region, so that it cannot be positioned properly on the membrane"
Experimental Evidence
Authors
Koga A; Hori H
Abstract
The i locus of the medaka fish, Oryzias latipes, is responsible for tyrosinase expression, and several mutant alleles have been identified. The genotype i1/i1 exhibits a complete albino phenotype, having pale orange-red skin and red eyes. This mutant lacks in vivo tyrosinase activity. The genotype i4/i4, on the other hand, shows a quasi-albino phenotype with skin as bright as that of i1/i1 but with red-wine-colored eyes. At the light microscope level, reduced pigmentation is observed both in the skin and eyes of this mutant. The tyrosinase genes for the i1 and the i4 alleles were cloned and sequenced, and compared with that of the wild-type tyrosinase gene. The i1 allele was found to contain a 1.9-kb transposable element in the 1st exon, and the i4 allele was found to contain a 4.7-kb transposable element in the 5th exon. Both i1 and i4 are alleles that were found in a commercial breeding population. The insertion of a transposable element thus appears to constitute a natural cause of mutations that cause albinism in this organism.
Additional References
RELATED GEPHE
Related Genes
Related Haplotypes
No matches found.
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