Ruby-eye 7 Jackson (ru-7J); a new remutation in the Hps6 gene
Louise Dionne, Patricia Ward-Bailey, Richard Samples, Roderick Bronson and Kenneth Johnson
Source of Support: This research was supported by NIH/NCRR grant RR01183 to the Mouse Mutant Resource (M.T. Davisson, PI) and Cancer Center Core Grant CA34196.
Mutation (allele) symbol: Hps6ru-7J
Mutation (allele) name: ruby-eye 7 Jackson
Gene symbol: Hps6
Strain of origin: B6.129S4-Cd86tm1Shr/J
Current strain name: B6(129S4)-Hps6ru-7J/J
Stock #: 005559 (view JAX® Mice Data Sheet for additional information including Price and Supply Information)
Phenotype categories: coat color
Origin and Description
A new spontaneous recessive remutation of ruby-eye ( Hps6ru )has been identified. Mice carrying this new remutation were discovered in a colony of B6.129S4-Cd86tmlShr (Stock # 003609) at the Jackson Laboratory. Mice homozygous for the new remutation were crossed to C57BL/6J mice to eliminate the Cd86 targeted mutation. Mutants are recognized by a grey coat color and ruby colored eyes. (See Photo) Like the previously described ruby-eye mutation, mice homozygous for Hps6ru-7J also have severe loss of pigment in the retina and in the ear skin. The B6(129S4)-Hps6ru-7J/J colony is maintained by homozygous and heterozygous sibling matings.
Genetic Analysis
Using standard mapping protocols, this new remutation was mapped to Chromosome 19 between markers D19Mit11 (NCBI 36 position 42.4 Mb), and D19Mit58 (NCBI 36 position 50 Mb), and is non-recombinant with D19Mit17 (NCBI 36 position 45.6 Mb).
Based on map position and phenotype similarities to the previously described ruby-eye (ru) mutation, a complementation test was performed. A mouse homozygous for the ruby-eye mutation (B6.Cg-Hps6ru/JLlp was bred to a mouse heterozygous for this new mutation. This mating produced 1 litter of 5 progeny of which 3 displayed the ruby-eye phenotype, proving this new remutation is an allele of ruby-eye (Hps6ru).
Pathology
A routine pathological screen of two mutants and two controls at eight and thirteen weeks of age and revealed no gross abnormalities in any of the mice.
Hearing as assessed by auditory brainstem response (ABR) testing of three homozygous mutants and one control at four weeks of age revealed no hearing loss.
The eyes of one homozygous mutant were examined with an opthalamscope and had severe pigment loss in the peripheral retina. Electroretinogram (ERG) testing was normal.
Acknowledgements
The authors wish to thank Serena Lovely for mutant discovery, Norm Hawes for the eye examination, and Coleen Marden for her excellent technical assistance.
