Ecdysteroids in vitro promote differentiation in the accessory glands of male mealworm beetles

Physiological peak doses of 20-hydroxyecdysone were added to organ cultures of young pupal accessory glands of male Tenebrio molitor. During subsequent culture in vitro or in vivo, the glands accumulated adult-specific antigens. Control organ cultures showed no such antigen accumulation. In this system, ecdysteroid controls not only cell cycles but also differentiation.