2002 Volume 48 Issue 4 Pages 317-324
We investigated the effect of exposure of pregnant mice to diesel exhaust on male gonad development at the level of mRNA expression. Expression of mRNAs for steroidogenic factor-1 (Ad4BP/SF-1) and Müllerian inhibitory substance (MIS), which are essential for male gonadal differentiation, decreased significantly in male fetuses when maternal mice were exposed to diesel exhaust at levels of 0.1 mg and 3.0 mg diesel exhaust particles (DEP)/m3 for 8 hr per day between days 2 and 13 post coitum. Expression levels of mRNAs for steroidogenic cytochrome P450 genes regulated by Ad4BP/SF-1, especially 3β-hydroxysteroid dehydrogenase (3β-HSD) and aromatase, were also decreased by exposure to diesel exhaust. There were no significant differences in levels of estrogen receptor (ER) or androgen receptor (AR) mRNAs between control and exposed mice. The data indicate that exposure of pregnant mice to diesel exhaust affects the expression of genes essential in the early stages of embryonic development.