17α, 20β-dihydroxy-4-pregnen-3-one induced substances, trypsin and 11β-hydroxy steroid dehydrogenase, are important factors for control of spermatogenesis in Japanese eel

Using cDNA subtraction and differential screening, we identified 25 genes that were differentially expressed by 17α, 20β-dihydroxy-4-pregnen-3- one (DHP) stimulation. Among these clones, eel trypsin and eel 11β-hydroxysteroid dehydrogenase short form (e11 β-HSDsf) were analyzed. The results indicate that transcripts of eel trypsin and e11β-HSD in testis were induced by DHP stimulation. In vitro experiments revealed that trypsin induces initiation of meiosis and spermiogenesis. Moreover, Cortisol enhanced the 11-ketotestesterone (HKT)-induced spermatogonial proliferation. From these results, we conclude that these two molecules are important for controlling spermatogenesis.