Two recessive rex coat mutants in the guinea pig

Two rex type coat mutants of the guinea pig were found to display monogenic recessive inheritance at independent loci. The mutant alleles were designated rex (rx) and waved (wv). Both genes modify the normal smooth coat to a more upright, somewhat unkempt pelage. Macroscopically, the two rexes are scarcely distinguishable. Microscopically, however, small differences are apparent in the degree of coat modification. The hairs of rex show a greater curvature than normal and have irregular secondary bends and twists and variable diameter; so do those of waved, but to a lesser degree. The vibrissae of rex are curved or bent and may break off; those of waved are a mixture of straight, curved, and bent hairs.