The effects on mouse development of interactions of 5-fluorouracil with Strong's luxoid gene and its plus and minus modifiers.

Abstract

AbstractPregnant females of five lines of mice selected for plus‐ and minus‐modifying genes of the limb‐skeleton effects of Strong's luxoid gene (lst) were each injected ip on days 8–11 of gestation with a single dose of 0.25, 0.50, or 0.75 mg of 5‐fluorouracil (5‐FU). The incidence and degree of expression of effects (cleft palate, neural hernia, eye defects, radial and tibial hemimelia, polydactyly, ectrodactyly, tail kinks, etc) varied according to the day of injection, dose of 5‐FU, genotype of the embryo ( + / +, + lst, lst/lst), and residual genotype (plus‐ or minus‐modifying genes of lst). 5‐FU increased the expression of the effects of lst on the skeleton. This action of 5‐FU was inhibited by minus and promoted by plus‐modifying genes of lst. Thus, 5‐FU and 1st may affect skeleton development in similar ways.