Comparative Litter and Reproduction Characteristics of Mouse Populations with X-Ray Exposure,Including 45 Generations of Male Progenitors 1

Summary

Observations were made of comparative litter and reproduction characteristics of two H-2 genotype substrains of mice within each of two lines. Two substrains (H-2^f and H-2^k) were from 45 generations of X-irradiated male progenitors, and two were from F₄₅ nonirradiated progenitors. No cumulative radiation-induced genetic decrement was noted in irradiated line mice of either H-2 substrains. A comparison of F₆ with F₄₆ data showed no degradation in reproductive fitness during 40 generations of X-ray exposure. The F₄₆ data suggest that a single gene effect on weaning weights may exist.

We acknowledge Gary L. Tietjen of the Statistical Group of the LASL Computer Division for data analysis.