Allele Symbol: MitfMi-ws
Name: white spot
Chromosome: 6; 40.0 cM
Alteration at locus: Radiation Induced
Gene Symbol: Mitf
Name: microphthalmia-associated transcription factor
Alteration at locus: Radiation Induced
ES Cell Line: Not Applicable
Heterozygous mice have a large white belly spot and more white on their tail (about half of the tail is white) when compared to C57BL/6J mice. Homozygous mice are white with eyes that are near normal size.
White Spotting mutants
Characteristics of the Mitf Locus:
Microphthalmia (Mitf) locus encodes the basic-helix-loop-helix-leucine zipper protein transcription factor MITF (Microphthalmia associated transcription factor). (9, 26, 27). Tissues/organs that may be affected (depending upon the allele) include pigmentation of the skin, pigmentation and development of the eye and ear, mast cells, osteoclasts, and reproductive cells. Mitf is an important transcription factor that functions to initiate transcription at several other loci within the pigment cell, including tyrosinase (tyr) and tyrosinase-related protein I (TyrpI.) and also regulates Bcl2. In other cell types, for example in osteoclasts and mast cells, Mitf functions as transcription factor of several cell-type specific proteins. There is no evidence that the size of white spots on mice mutant at Mitf are influenced by pheomelanin. However, mice that are both recessive yellow and Miwh/+ in genotype are much more eumelanic than mice that are yellow and +/+ (Lamoreux, 1981). Strain background does not appear to influence size or location of spots in mice mutant at Mitf.
Strain of Origin: C57BL/6
Strain genetic background: C57BL/6J
Strain Development: gamma-irradiation induced mutation
Suggested Control Mice:
Donor: Lynn Lamoreux, Ph.D., Texas A & M University
Feed mouse chow that contains 9 percent fat for breeding animals.
Coat color: Heterozygous: black, Homozygous: white (see description under phenotype)
MMRRC Breeding System: Sibling or Backcross
Overall Breeding Performance: Good if homozygous males are mated to either heterozygous or wild type females. Poor if homozygous males are mated to homozygous females.
|Viability and Fertility:||Female||Male||Comments|
|Homozygotes are viable:||Yes||Yes|
|Homozygotes are fertile:||Poor||Yes|
|Heterozygotes are fertile:||Yes||Yes|
|Age Reproductive Decline:||Unknown||Unknown|
Average litter size: 6
Recommended wean age: 4 weeks
Limited quantities of breeder mice (recovered litter) are available from a cryoarchive; recovered litter usually available to ship in 3 to 4 months.
Fee/unit (US $)
|Litter||Recovered litter1; additional fees for any special requests.|
|Aliquot||Approximate quantity3: 20-40 embryos / aliquot|
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 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 is one straw or vial with sufficient sperm to recover at least one litter of mice, as per provided protocols, when performed at the MMRRC facility. The MMRRC makes no guarantee concerning the 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.
To request material from the MMRRC: Please fill out our on-line request form (accessible from the catalog search results page, or click the Request this Strain button in the fees section). If you have questions or need assistance completing this form, you may call Customer Service at (800) 910-2291 (in USA or Canada) or (530) 757-5710 (international calls). Before you call, please have with you: the MMRRC item number, quantity needed, Bill-to and Ship-to contact information.