Fig. 5.

Comparative susceptibilities of the reciprocal F1 progeny and the resistant BALB/cJ (C) and susceptible DBA/2J (D2) parental strains. (A) Comparison of the reciprocal F1 crosses D2CF1 and CD2F1 (based on mean values of both sexes) and the parental strains. (B) Comparison of males and females of the crosses (CD2F1 and D2CF1) and the parental strains. Results are consistent with a possible paternal mode of inheritance, with reciprocal F1 offspring having survival times most similar to those for the inbred strain of the sire. A lethal dose of B. anthracis spores (2,000 spores/mouse) optimized for BALB/cJ was used for all inoculations. Survival time, expressed as TTD (in hours) is plotted as the mean and standard error of the mean for the number of animals in a given group. Abbreviations: M, male; F, female; M+F, both sexes averaged; n, total number of animals tested for each mouse strain.