INDUCTION OF CHORIOGENESIS BY 20-HYDROXYECDYSONE IN THE GERMAN-COCKROACH

Experiments in vitro have shown that 20-hydroxyecdysone (at a concentr ation of 0.2 and 2 muM and after 12 and 24 hr of incubation) is able t o induce the precocious deposition of chorion materials by the follicu lar epithelium of young oocytes of the cockroach Blattella germanica. Since previous studies had shown that 20-hydroxyecdysone levels in B. germanica ovaries increase with oocyte maturation to reach a peak just before oviposition, we therefore hypothesize that ovarian ecdysteroid s trigger choriogenesis in this species through an autocrine action.