Pearl 15 Jackson, a remutation of the Ap3b1 gene

Richard M. Samples, Patricia F. Ward-Bailey, Jieping Wang, Leah Rae Donahue, Roderick T. Bronson, and Muriel T. Davisson

Source of Support: The research was supported by NIH/NCRR grant RR01183 to the Mouse Mutant Resources (M.T.Davisson,PI) and Cancer Center Core Grant CA34196.

Mutation (allele) symbol: Ap3b1pe-15J

Mutation (allele) name: pearl 15 Jackson

Gene symbol: Ap3b1

Strain of origin: C3.Sw-H2b/SnJ

Current strain name: C3(SW)-H2bAp3b1pe-15J/J

Stock #: 005952 (available only as DNA from the Jackson Laboratory DNA Resource)

Phenotype categories: Coat color

Origin and Description

The Ap3b1pe-15J remutation was discovered by Dawn Martin in a production colony of  C3.Sw-H2b/SnJ mice (Stock #000438) in AX-12 at the Jackson Laboratory.  Mice homozygous for this spontaneous, recessive mutation are recognizable by a diluted light gray coat color. This dilution also lightens the eyes, feet, ears and tail.(See Photos-dorsal view and  ventral view) Both homozygous males and females breed and live a normal life span. Descriptions of three other remutations of the Ap3b1 gene, Ap3b1pe-13J , Ap3b1pe-14J and AP3b1 pe-16J pe-16J are also available on this web site.

Genetic Analysis

The Ap3b1pe-15J mutation was first identified as a recessive mutation by crossing a female C3H.Sw/SnJ mouse carrying this new mutation to an inbred C57BL/6J mouse. In this cross no mutants were produced in the F1 generation, but mutants were produced in the F2 intercross generation. Using our standard mapping procedures  an intercross with CAST/Ei was set up and generated 42 affected progeny that were used for linkage analysis. This new mutation maps on mouse Chromosome 13 between D13Mit191 (NCBIm34 position 70.2 MB) and D13Mit147 (NCBIm34 position 94.3 Mb) and is non-recombinant with D13Mit191 (NCBIm34 position 81.5 Mb), D13Mit159 (NCBIm34 position 88.8 MB), and D13Mit128 (NCBIm34 position 93.5 Mb).

Based on phenotype and map position similarity of this new mutation to the previously described Ap3b1pe (NCBIm34 position 90.5-90.7 Mb) mutation, a direct test for allelism was set up by mating a female mouse, homozous for the Ap3b1 pe-11J mutation, to a male homozygous for this new mutation. This mating produced a litter with a total of 7 progeny of which all were affected, proving the new mutation to be an allele of the Ap3b1pe gene.

Pathology

A routine pathological screen done on one homozygous and one heterozygous mouse showed no lesions.

Acknowledgements

The authors wish to thank Dawn Martin for the discovery of the mutant and Coleen Marden for her excellent technical assistance