Effects of Age of Parents on Characteristics of the Guinea Pig

Publisher Website
Google Scholar
Abstract
The paper deals with nearly 2000 guinea pigs descended from a single mating in the 12th generation of brother-sister mating. This stock showed much variation in the amount of white in the piebald pattern, none of which however was hereditary and very little even due to factors common to littermates. All branches produced polydactyls in proportions which varied from 10 to 69%, with no hereditary differences within the branches but with a strong tendency to resemblance between littermates. The amount of white in the coat increased regularly (56-67% in [male], 61-73% in [female]), as the age of the dam increased from less than 6 months to more than 21 months. The percentage of polydactyls decreased in each branch of the family with increasing maturity of the dam, the drop in the whole family being from 53 to 14%. The correlation ratio between age of dam and amount of white in progeny was about 13 times its probable error (.190 [plus or minus] .015), and that between age of dam and percentage of polydactyls was over 20 times its probable error (.370[plus or minus].018). Sex was the only other factor found to affect percentage of white within the stock, and heredity and season the only other important factors in the case of polydactylism, a significant excess of polydactyls being produced in the winter months. The age effect on polydactylism induced no detectable hereditary change. The effect is interpreted as due to immaturity rather than to senescence.

This publication has 0 references indexed in Scilit: