Strain Detail Sheet

Phenotype:
In the homozygous state, this mutant allele results in a light sandy brown/beige coloration on the C57BL/6J background strain.

Characteristics of the Locus: The albino (Tyr) locus encodes the rate-limiting enzyme for pigmentation, which is TYROSINASSE. The absolute requirement for functional TYROSINASE to catalyze the formation of melanin pigment is illustrated by the phenotypes of mice that lack this locus as a result of deletion, for example mice heterozygous for two overlapping deletions, MMRRC:009964 and MMRRC:009965 in which the albino locus is absent. The mice also lack all melanin pigment. Vertebrates that lack normal tyrosinase are characterized by reduction or absence of pigmentation in the eyes and/or skin. If the reduction of pigmentation is severe, optic nerve development may be abnormal, resulting in blindness. Reduction of melanogenesis may result from failure of normal tyrosinase function caused by its abnormal interaction with other proteins, from defects in its regulatory region, from absence or defect of the structural gene. The series of natural mutations that affect availability of normal tyrosinase function includes mutants of this type. C57BL/6J-Tyr^c-2J/Tyr^c-2J, available at The Jackson Laboratory, lacks tyrosinase activity as a result of point mutation in the structural region of the gene; Acromelanic (MMRRC:000140) may have a similar defect. Extreme dilution (MMRRC:000141) seems to have nearly normal pigmentation in the eyes, but their hair pigmentation is a uniform gray. In dark-eyed-albino (MMRRC:000139) the eye pigmentation is somewhat reduced, but intense, while the hair is unpigmented. Chinchilla mice(MMRRC:000144) are very dark, nearly black. Two of the mutant alleles, chinchilla mottled (MMRRC:000145) and extreme dilution mottled (MMRRC:000142) result in chimerism of hair and eye pigmentation that has been attributed to a rearrangement of the DNA 5kb upstream of the tyrosinase locus. One of the genes that regulates the activity of TYROSINASE is MITF. And there are functional interactions between TYROSINASE and TYROSINASE-RELATED PROTEIN within the pigment cell.

Strain Type: Congenic Spontaneous Mutant

Founder genetic background: Wild caught mouse, circa 1920 by JE Knight.

Strain genetic background: C57BL/6J

Strain Development:
First observed in wild mice trapped by JE Knight; later studied by JA Detlefsen; see note in Festing's Inbred Strains of Mice: CE. Backcrossed to C57BL/6J at least 10 generations then bred to homozygosity and maintained by sibling mating.

• Pigmentation research

Donor: Dr. ML Lamoreux, Texas A&M University

Primary Reference:

Detlefsen JA. A new mutation in the house mouse. Am. Naturalist. 1921 Sept.-Oct.;55:469-473.

Moyer FH. Genetic variations in the fine structure and ontogeny of mouse melanin granules. Am Zool. 1966 Feb;6(1):43-66. (Medline: 5902512)

Lamoreux ML. The inbred mouse in pigmentation research: significance of a congenic developmental system. Pigment Cell Res. 2000 Dec;13(6):421-30. Review. (Medline: 11153693)

Coat color: Beige

Other:

MMRRC Breeding System: Sib mating

Breeding Scheme(s):

• Homozygous female x Homozygous male

Generation: Unknown

Overall Breeding Performance:

Feed 9% fat mouse diet.

* Additional charges may apply for any special requests. Shipping costs are in addition to the basic distribution/resuscitation fees. Information on shipping costs and any additional charges will be provided by the supplying MMRRC facility.

Click button to Request this one strain. (Use the MMRRC Catalog Search to request more than one strain.)
MMRRC Item # Description	Distribution Fee/unit (US $)	Units	Notes
000141-MU-RESUS Litter recovered from cryo-archive	$2,022.00 Non-Profit $4,109.00 For-Profit	Litter	Recovered litter1; additional fees for any special requests.
000141-MU-SPERM Cryo-preserved spermatozoa	$437.00 Non-Profit $817.00 For-Profit	Aliquot	Approximate quantity.2

¹ The distribution fee covers the expense of resuscitating mice from the cryo-archive; you will receive the resulting litter. The litter will contain at minimum one breedable mutant carrier; the actual number of animals and the gender and genotype ratios will vary. (Typically, multiple breeder pairs can be established from the recovered litter.) Prior to shipment, the MMRRC will provide information about the animals recovered. If you anticipate or find that you need to request specific genotypes, genders or quantities of mice in excess of what is likely from a resuscitated litter, you may discuss available options and pricing with the supplying MMRRC facility.

² An aliquot contains sufficient material (volume and concentration) for at least two IVF or several artificial inseminations (based on our procedures). The MMRRC makes no guarantee concerning success of these procedures when performed outside the MMRRC facilities.

³ An aliquot contains a sufficient number of embryos (in one or more vials and based on the transfer success rate of the MMRRC facility) to transfer to at least two recipients. The MMRRC makes no guarantee concerning embryo transfer success experienced in the recipient investigator's laboratory. Neither gender nor genotype ratios are guaranteed.