Juvenile hormone and ecdysteroids as major regulators of brain and behavior in bees

The genome sequencing of several bee species, and the development of functional genomics tools, paved the way for understanding the fascinating behaviors of bees in molecular terms. Here we review recent progress in research on the hormonal regulation of bee behavior, with emphasis on two key insect hormones: Juvenile hormones (JH) and ecdysteroids (Ec). We discuss recent progress in deciphering the molecular bases for JH regulation of gene expression in the nervous system and other tissues. The patterns of JH-dependent changes in gene expression show many similarities across tissues, which are associated with the effects of JH on worker task allocation. Ec, which have previously been studied mainly in the context of insect development, now appear to also play imortant roles in the regulation of many molecular processes in the brain that are asociated with bee behavior. Finally, we discuss the possibility that JH-signaling and Ec-signaling pathways interact to shape the complex behavioral repertoire of bees.