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Fig. 3 | Zoological Letters

Fig. 3

From: Recent progress in understanding the role of ecdysteroids in adult insects: Germline development and circadian clock in the fruit fly Drosophila melanogaster

Fig. 3

Scheme illustrating ecdysone signaling factors in the molecular machinery of the Drosophila circadian clock. The figure is modified from Itoh and Matsumoto [92]. The signal of 20-hydroxyecdysone (20E), the most biologically active ecdysteroid, is transduced primarily through the action of the specific receptor for 20E. This receptor is a heterodimer of Ecdysone receptor (EcR) and Ultraspiracle (Usp), which binds a specific DNA element when 20E is present. The 20E-bound form of EcR/Usp complex activates transcriptions of vrille (vri) and Early gene at 23 (E23). The CLK-CYC also activates transcriptions of period (per), vri and E23. The E23 protein specifically negates the 20E response. Furthermore, this EcR-Usp complex starts the ecdysteroid cascade with the expression of E75. The E75 and UNF activate transcriptions of per

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Zoological Letters

ISSN: 2056-306X

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