Insights into the molecular basis of the hormonal control of molting and metamorphosis from Manduca sexta and Drosophila melanogaster.
This short review summarizes our current knowledge about the role of transcription factors regulated by ecdysteroids and juvenile hormone (JH) in larval molting and metamorphosis in the tobacco hornworm, Manduca sexta, and Drosophila melanogaster. We show new evidence that EcR-A/USP-2 and E75A contribute to the down-regulation of MHR3 after the peak of ecdysteroid. Also, there is suggestive evidence that both MHR4 and betaFTZ-F1 may regulate the expression of dopa decarboxylase as the ecdysteroid titer declines. We summarize the regulation by JH of the Broad transcription factor that normally appears in the epidermis in the final larval instar and specifies pupal cuticle formation at the metamorphic molt. Premature expression of different Broad isoforms also is shown to cause precocious degeneration of the prothoracic glands as well as to prevent ecdysteroid release during its presence.
Department of Biology, University of Washington, 24 Kincaid Hall, Box 351800, Seattle, WA 98195-1800, USA. lmr@u.washington.edu
Lynn M
LM
Riddiford
Kiyoshi
K
Hiruma
Xiaofeng
X
Zhou
Charles A
CA
Nelson
D000818:Animals; D004331:Drosophila melanogaster / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D007301:Insect Hormones / Q000494:pharmacology*; D007814:Larva / Q000254:growth & development / Q000378:metabolism; D018402:Manduca / Q000196:embryology / Q000502:physiology*; D008675:Metamorphosis, Biological / Q000502:physiology*; D018978:Molting / Q000502:physiology*; D011679:Pupa / Q000254:growth & development / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D007301:Insect Hormones; D014157:Transcription Factors