The responsiveness of epididymal beta-defensins to androgen manipulation as revealed by quantitative RT-PCR. RNA samples were prepared from the caput epididymides of intact mice (Intact) and mice castrated for 7 days and supplemented with oil (Oil) or testosterone propionate (TP). Different genes showed different responsiveness to androgen. A) The gene expression was fully or partially dependent on androgen. *: P < 0.01 Oil group versus Intact group; **: P < 0.05 TP group versus Oil group. ***: P < 0.05 TP group versus Intact group. B) The expression of Defb25 was dependent on testicular factors and not on androgen, whereas the expression of other genes was independent on testicular factors or androgen. *: P < 0.05 Oil group versus Intact group.