Ruby-eye 2-like (ru2l): a new spontaneous mutation causing a light coat color and red eyes.

Son Yong Karst, Patricia F. Ward-Bailey, Leah Rae Donahue, Kenneth R.

Johnson, 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: ru2l

Mutation (allele) name: ruby-eye 2-like

Gene symbol: ru2l

Strain of origin: C.C3Tlr4Lps-d/J

Current strain name: C.C3Tlr4Lps-d/J-ru2l/J

Stock #: 006962 (view JAX® Mice Data Sheet for additional information including Price and Supply Information)NOTE: After 4-24-2008 available as DNA only from the Jackson Laboratory DNA Resource.

Phenotype categories: color

Abstract

The new autosomal recessive ru2l mutation arose spontaneously at the Jackson Laboratory and has been named ruby-eye 2-like. This new mutation maps to Chromosome 7 in the same region as the previously described  ruby-eye 2 (Hps5 ru-2)mutation. A direct test for allelism was not done because the original ruby-eye 2 mice are cryopreserved and currently not available for testing.

Origin and Description

The ru2l mutation was found by Candice Braley in a production colony of C.C3-Tlr4Lps-d/J mice at the Jackson Laboratory. Mice homozygous for the ru2l mutation have dark red eyes at weaning age, but, as the mice age, the eyes become a lighter red color. The normal agouti coat color as seen in control littermates is diluted to a lighter color in the ru2l mutant mice (See Photo), and the dark pigment of the tail is diluted to a pink color. Mutant mice carrying the ru2l mutation are viable and fertile.

Genetic Analysis

Using standard MMR mapping procedures a female mouse homozygous for the ru2l mutation was mated to a CAST/Ei male mouse,  and a male mouse homozygous for the ru2l mutation was mated to a CAST/Ei female mouse. The F1 progeny from these matings were then intercrossed and produced 53 affected progeny that were utilized for linkage analysis. The new ru2l mutation maps to Chromosome 7 between D7Mit267 (NCBI 36 position 29.2 Mb) and D7Mit230 (NCBI 36 position 49.3 Mb) and is non- recombinant with D7Mit170 (NCBI 36 position 47.2 Mb). The previously described ruby eye 2 (Hps5 ru-2) mutation is at (NCBI 36) position 46.6 Mb.

Pathology

A routine pathological screen of one homozygous ru2l mutant mouse and a littermate control at 12 weeks age showed no gross abnormalities.

Hearing as assessed by auditory brainstem response (ABR) testing of one homozygous ru2l mutant mouse at 14 weeks of age revealed no hearing loss.

The eyes of one homozygous ru2l mutant mouse at 14 weeks age were examined with an opthalamascope and were determined to be normal. ERG testing of the same mouse was also normal.

 

Acknowledgements

The authors thank Candice Braley for discovery of the mutant, Chantal Longo-Guess for hearing assessment, Norm Hawes and Ron Hurd for the eye examinations and Coleen Marden for excellent technical skills.