Frequency of t w Alleles in a Confined Population of Wild House Mice. ∗

Abstract

Summary

1. A sample (R-3) from a confined population of mice, consisting of 70 males and 68 females, was tested for the presence of t ^w alleles. This population is descended from animals caught in the wild. 2. Of 44 tested males, 50% were ±/t ^w; while of 55 tested females, 65% contained t ^w. This population has an overall-frequency of 59% t ^w containing fertile individuals. The present generation of this population seems to contain only t ^w2, a viable allele, and ±. Previously tested generations (R- 1 and R- 2) had contained both t ^w2 and t ^w1. The latter is a lethal allele. 3. The ±/t ^w2 males of this population transmitted t ^w2 gametes to their offspring in excessive numbers, a phenomenon known from other studies and referred to as “segregation ratio abnormality.” 4. Discussed is the overall high frequency of t ^w-containing individuals found in this population as compared with animals caught in the wild. Also discussed is the disparity between males and females with respect to frequencies of sterility and t ^w-containing individuals.