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Behavioral and electrophysiological evidence has suggested that sex pheromone is rapidly inactivated within the sensory hairs soon after initiation of the action-potential spike. We report the isolation and characterization of a sex-pheromone-degrading enzyme from the sensory hairs of the silkmoth Antheraea polyphemus. In the presence of this enzyme at(More)
cDNAs were isolated from Manduca sexta that encode two isoforms of an ultraspiracle (USP) homologue MsUSP-1 and MsUSP-2 with different N-terminal A/B regions. The MsUSP-1 cDNA predicts a protein with 97% and 45% amino acid identities in the DNA- and ligand-binding domains respectively to the Drosophila USP and 89% overall identity with Bombyx mori CF1 (an(More)
Insect metamorphosis is a fascinating and highly successful biological adaptation, but there is much uncertainty as to how it evolved. Ancestral insect species did not undergo metamorphosis and there are still some existing species that lack metamorphosis or undergo only partial metamorphosis. Based on endocrine studies and morphological comparisons of the(More)
The understanding of the molecular basis of the endocrine control of insect metamorphosis has been hampered by the profound differences in responses of the Lepidoptera and the Diptera to juvenile hormone (JH). In both Manduca and Drosophila, the broad (br) gene is expressed in the epidermis during the formation of the pupa, but not during adult(More)
BACKGROUND The timely onset of metamorphosis in holometabolous insects depends on their reaching the appropriate size known as critical weight. Once critical weight is reached, juvenile hormone (JH) titers decline, resulting in the release of prothoracicotropic hormone (PTTH) at the next photoperiod gate and thereby inducing metamorphosis. How individuals(More)
Ecdysteroids acting through multiple isoforms of the ecdysone receptor (EcR) initiate molting and metamorphosis of insects. Two isoforms of EcR, A (this paper) and B1 (Fujiwara et al., Insect Biochem. Mol. Biol. 25, 845-856, 1995), were isolated from the tobacco hornworm, Manduca sexta, and shown to be similar to the corresponding Drosophila EcR isoforms.(More)
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(More)