Strain Detail Sheet

Phenotype:
Description of White Spotting mutants
Description of White Kit mutants

A dominant mutation that is lethal in the homozygous state. Mice that carry the mutant allele are black with white spotting; homozygous ^+/+ mice are solid black. Heterozygous mice with the mutant allele have fewer pigment cells (more white areas) than heterozygous mutant mice on the C57BL/J background.

MMRRC:000173 was selected for normal expression level of the Kit^W-2J mutation compared to MMRRC:000174 in which hi level expression was selected for and MMRRC:000175 in which low level expression of the mutation was selected for by continued inbreeding.

In this collection of mice, the identical allelic origin is expressed in five different degrees of severity (stocks 173, 174, 175, 177, 178), depending upon the congenic background, and within the congenic mice upon two (or more) discrete modifying genes that have been maintained by selection. The orginal stock (MMRRC:000173) was received from The Jackson Laboratory, where the mutation occurred in the C57BL/6J stocks of Dr. Elizabeth Russell. The allele is homozygous lethal. Heterozygotes of this stock (MMRRC:000174) have a high degree of spotting for this allele on a C57BL/6J background and is maintained with strong selection. The allele from the original stock, (MMRRC:000173) , was also backcrossed onto a different inbred strain, JU/CtLm where the spotted mice have at least twice the extent of white spotting (MMRRC:000177). This stock gave rise to one offspring with a yet greater degree of spotting that is inherited as a semi-dominant trait. Mice that are heterozygous for the Kit^W-2J allele and homozygous for the hi-spot trait on the JU/CtLm background are almost completely white (MMRRC:000178), whereas mice of the C57BL/6J-^W-2J/+ lo-spot stock (MMRRC:000175) are often almost completely lacking defined white spots. The hi-spot trait was then crossed back onto C57BL/6J, with strong selection in the presence of Kit^W-2J, resulting in yet another phenotype consisting of considerably more white than is normal for this allele on a C57BL/6J background. The spots on this stock (MMRRC:000174) are sharply defined, which is not usual for Kit spotting.

Mammalian Phenotype Terms:
      assigned by genotype

Kit^W-2J/Kit⁺

• no phenotypic analysis
• no phenotypic analysis (MGI Ref ID J:23000)

Strain Type: Congenic

Founder genetic background:

Strain genetic background: C57BL/6

Strain Development:
Spontaneous mutation in C57BL/6J

• Pigmentation

Donor: Lynn Lamoreux, Ph.D., Texas A&M University

Primary Reference:

Lamoreux ML, Russell ES. Developmental interaction in the pigmentary system of mice. I. Interactions between effects of genes on color of pigment and on distribution of pigmentation in the coat of the house mouse (Mus musculus). J Hered. 1979 Jan-Feb;70(1):31-6. (Medline PMID: 469221)

Lamoreux ML. Strain-specific white-spotting patterns in laboratory mice. Pigment. Cell Res. 1999 Dec;12(6):383-90. (Medline PMID: 10614578)

Coat color: White spotting (see photo)

Other:

MMRRC Breeding System: Sib mating

Breeding Scheme(s):

• Heterozygous female x Heterozygous male
• Wildtype female x Heterozygous male
• Heterozygous female x Wildtype male

Generation: F>100

Overall Breeding Performance: Extremely poor

Feed 9% fat breeder chow.

Kit heterozygous mice (Kit^W-2J/+) have fewer oocytes than normal mice and also the homozygotes are lethal in all cases, so spotted males should be mated to black females in all cases when possible. They should be mated when young. This stock should be mated inter se. The black littermates can serve as controls for their heterozygous sibs.

* 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
000174-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.
000174-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.