Fig. 9. Summary diagram of the hormonal regulation of Broad (BR) protein expression and its role in the specification of pupal development based on studies of its action on cuticle genes. Juvenile hormone (JH) prevents the pupal molt, by preventing the activation of the br gene by ecdysone and prevents the adult molt by preventing the suppression of br by ecdysone in JH-sensitive tissues. BR is sufficient to activate the pupal program and to suppress both the larval and the adult programs. See text for details.