Differentially expressed regulatory genes in honey bee caste development

In the honey bee, an eminently fertile queen with up to 200 ovarioles per o vary monopolizes colony level reproduction. In contrast, worker bees have o nly few ovarioles and are essentially sterile. This phenotype divergence is a result of caste-specifically modulated juvenile hormone and ecdysteroid titers in larval development. In this study we employed a differential-disp lay reverse transcription (DDRT)-PCR protocol to detect ecdysteroid-regulat ed gene expression during a critical phase of caste development. We identif ied a Ftz-F1 homolog and a Cut-like transcript. Ftz-F1 could be a putative element of the metamorphic ecdysone response cascade of bees, whereas Cut-l ike proteins are described as transcription factors involved in maintaining cellular differentiation states. The downregulation of both factors can be interpreted as steps in the metamorphic degradation of ovarioles in worker -bee ovaries.