| Abstract: | Hormonal control of ovarian development was examined in Bombyx mori. The weight of the ovary increased suddenly by 3 days after pupal ecdysis, and vitellogenin could be immunologically detected in the ovary at that time. The ecdysteroid titers during pupal-adult development, quantified by radioimmunoassay, increased from day 0 to day 2. Ovarian development was arrested for a long period in brainless pupae and isolated pupal abdomens. Injection of 20-hydroxyecdysone into such preparations stimulated development of the ovaries, and vitellogenin could be detected in ovaries 2 days after injection. The results suggest that 20-hydroxyecdysone acts by stimulating the growth of ovary. |
