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Spontaneous Allele Detail
Symbol: Tyrc
Name: tyrosinase; albino
MGI ID: MGI:1855976
Synonyms: c
Gene: Tyr  Location: Chr7:87073979-87142720 bp, - strand  Genetic Position: Chr7, 49.01 cM
Tyrc/Tyrc and Tyrc/Tyrc-ch Oca2p/ Oca2p

Show the 4 phenotype image(s) involving this allele.

Strain of Origin:  old mutant of the mouse fancy
Allele Type:    Spontaneous
Mutation:    Single point mutation
Mutation detailsThe specific mutation in the albino allele is a G-to-C transversion causing an amino acid change from cysteine to serine at position 103 or 85 (p.C103S for pre-protein, p.C85S for mature protein). This mutation introduces a DdeI enzyme restriction site. (J:10889, J:40223)
Inheritance:    Recessive
View phenotypes and curated references for all genotypes (concatenated display).
In Mice Carrying this Mutation: 85 assay results
In Structures Affected by this Mutation: 6 anatomical structures
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Mouse strains and cell lines available from the International Mouse Strain Resource (IMSR)
Carrying this Mutation:  Mouse Strains: 78 strains available      Cell Lines: 0 lines available
Carrying any Tyr Mutation:  357 strains or lines available
Tyrc, albino. This very old mutant was already known in Greek and Roman times. Hair and eyes are completely devoid of pigment (J:5436, J:5001, J:30725). The albino mutation affects the amount of tyrosinase, and thus of melanin, in pigment cells, but does not interfere with the production of pigment cells themselves (J:12173, J:13092). Melanocytes with melanosomes showing normal fine structure occur in the retina and hair follicles. Pigment granules are smaller and fewer than normal and completely lack melanin (J:5346, J:5001, J:30725). Tyrosinase is almost absent (J:12173). Although Tyr is the structural gene for tyrosinase, some albino mutations may affect tyrosinase enzyme regulation rather than structure (J:6611), suggesting that these mutations affect tyrosinase inhibition (J:5346), presumably via control regions of the gene. All the mutant alleles are recessive to wild-type in phenotype, but heterozygotes with wild-type produce intermediate amounts of tyrosinase (J:12173). Albino-locus mutants with lightly pigmented eyes have a reduced number of fibers of the optic nerve going to the ipsilateral lateral geniculate nucleus of the brain. This is probably a secondary effect of reduced tyrosinase activity or amount of pigment in the pigment epithelium, since genes at other loci that reduce eye pigmentation also cause the same anomaly (J:5436, J:6064). Abnormal retinal pathways disrupted at the optic chiasm that occur in albinism can be corrected with a Tyr normal transgene (J:22320). Lipofuscin is a terminal oxidation product pigment that accumulates with age. In a cross of C57BL/6J and BALB/cJ, which differ in cardiac deposition of the pigment, this trait segregated with albinism, and is controlled by the Tyr locus (J:15460). Tyrc homozygotes do not perform as well as normal in a number of behavioral tests. It is likely that this effect is mediated, at least in part, by defective vision resulting from lack of retinal pigment (J:5470, J:5360, J:5378).
Original:  J:34484 Detlefsen JA, A new mutation in the house mouse. Am Naturalist. 1921 Sep-Oct;55:469-73
All:  42 reference(s)

Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB), Gene Ontology (GO)
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MGI 6.17
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