SILVERING IN A STRAIN OF GUINEA PIGS

Abstract

A type of silvering in the guinea pig is described which is most prominent on the young and gradually disappears as the animal reaches growth maturity. It is restricted to brown (bb) animals. The silver appearance is due to a white or faintly pigmented portion of the hair just back of the tip and often extending to the base. The ratios of silvers to non-silvers from various types of matings are aberrant so far as Mendelian ratios are concerned. The % of silvered progeny from silver X silver parents was 63.58, from silver X non-silver 32.65 and both parents non-silver 16.54. Silvering appears only on intense (C [long dash]) animals. It may occur on selfs (E) or tortoise (2p), but has not been observed on piebalds (ss). Sex of the silvers was 123 [male][male] to 128 [female][female]. This type of silvering has been reported from 2 other laboratories besides the Bureau of Animal Industry. Since the stock of these 3 laboratories is related, it is probable that the silvering had a common source of origin.