Ecdysone Control of Developmental Transitions: Lessons from Drosophila Research

Abstract

The steroid hormone ecdysone is the central regulator of insect developmental transitions. Recent new advances in our understanding of ecdysone action have relied heavily on the application of Drosophila melanogaster molecular genetic tools to study insect metamorphosis. In this review, we focus on three major aspects of Drosophila ecdysone biology: (a) factors that regulate the timing of ecdysone release, (b) molecular basis of stage- and tissue-specific responses to ecdysone, and (c) feedback regulation and coordination of ecdysone signaling.

Sexual transfer of the steroid hormone 20E induces the postmating switch in Anopheles gambiae

“…The discovery that male-transferred 20E is a key regulator of female reproductive biology in An. gambiae adds to the myriad of effects that this hormone exerts on insect adult physiology (2,3,(17)(18)(19)(20)(21)(22)(23). Interestingly, the steady decline of 20E levels in the atrium during the first day after copulation (17) is reminiscent of the process of mating plug digestion, which is completed in a similar time frame (5)(6)(7)16).…”

“…ecdysteroid in insects and regulates molting during juvenile stages (18). This hormone has been found to affect multiple aspects of adult insect physiology: It controls lifespan (19), learning (20), stress-induced responses (21), sleep regulation, and social interactions (22).…”

20-Hydroxyecdysone (20E) Primary Response Gene E93 Modulates 20E Signaling to Promote Bombyx Larval-Pupal Metamorphosis

“…Insect ecdysteroids include 20-hydroxyecdysone (20E) 2 , the most active form of molting hormone, and ecdysone, the immediate precursor of 20E (1). 20E binds to a heterodimer in the nuclear receptor complex, ecdysone receptor (EcR) and ultraspiracle protein (USP).…”

“…20E-EcR-USP triggers a transcriptional cascade, including transcription of the 20E primary response genes (i.e. the transcription factor genes Br-C, E74, E75, and E93) and subsequently the 20E secondary response genes (1,2). E93 was first identified as a 20E primary response gene in the fruit fly, Drosophila melanogaster (3), and it encodes a member of the helix-turn-helix (HTH) transcription factor family (4).…”

Low-molecular-weight metabolite systems chemistry

“…Steroid hormones comprise sex hormones, estrogens, such as estradiol (2.17), that regulate menstrual and estrous reproductive cycles, and testosterone (2.18), a hormone that occurs in both sexes but acts differently (Greenstein and Wood, 2011). Another steroid hormone, ecdysone (2.19), regulates insect developmental transitions (Yamanaka et al, 2013). Notably, ecdysones, can also be synthetized in significant amounts by plants (Williams et al, 1989).…”