m and Leprdb may still be segregating in this background, but have not been phenotypically detected in at least three cycles of backcross-intercross breeding.
The frizzy like mutation (frzl) phenotypically resembles the frizzy mutation (Prss8fr) and maps to an interval that includes Prss8 but has not been proven to be a mutation in Prss8. Frizzy like homozygotes can be identified by their wavy coat texture and curly whiskers at 7 to 9 days of age, when the first coat comes in. While the curly whiskers persist, the curl of the hair is reduced within a few weeks. At 4 weeks of age a deficiency of zigzag hairs and increased bends in the existing zigzag hairs was found. Because this spontaneous mutation has not been molecularly defined there is currently no genotyping assay for it so the mutation must be identified by phenotype. The frizzy mutation (Prss8fr) is available in stock #000619, FS/EiJ.
The frizzy like mutation arose spontaneously in 1998 in the BKS.Cg-m +/+ Leprdb/J colony at The Jackson Laboratory. This mutant subline was maintained via backcross-intercross and in 2007 sperm was cryopreserved from a homozygous male at generation N3F2.