Regulation of steroidogenesis in crayfish molting glands: involvement of protein synthesis.
The involvement of continuous protein synthesis in the mechanisms of crustacean steroidogenesis was investigated using crayfish molting glands (Y-organs). During intermolt, Y-organ steroidogenic activity is low. Eyestalk ablation initiates premolt which is characterized by a rapid increase in the production of ecdysteroids. In vitro incorporation of [14C]leucine into TCA-precipitable proteins was measured in Y-organs. A significant increase of de novo protein synthesis within 2 h and simultaneously led to a strong inhibition of the ecdysteroid synthesis. Sinus gland extracts (containing molt inhibiting hormone) also induced both a limited but reproducible inhibition of Y-organ protein synthesis and a pronounced inhibition of ecdysteroid production within 2 h. The results suggest a functional link between protein synthesis in the Y-organ and sustained ecdysteroid production. The analysis of autoradiographs from one-dimensional gel electrophoreses revealed an overall increase in de novo synthesis of glandular proteins in early premolt but also a more specific effect on distinct proteins (increase of 150, 140, 50-60, 22 and 15-18 kDa proteins) which may be more directly involved in the regulation of ecdysteroidogenesis.
Dauphin-Villemant
C
C
Ecole Normale Supérieure, Département de Biologie, CNRS URA686-IFREMER URM4, Paris, France.
Böcking
D
D
Sedlmeier
D
D
D000818:Animals; D003400:Astacoidea / Q000254:growth & development / Q000378:metabolism*; D003513:Cycloheximide / Q000494:pharmacology; D026461:Ecdysteroids; D004591:Electrophoresis, Polyacrylamide Gel; D004702:Endocrine Glands / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D007447:Invertebrate Hormones / Q000494:pharmacology; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D014176:Protein Biosynthesis; D013256:Steroids / Q000096:biosynthesis*
D026461:Ecdysteroids; D007447:Invertebrate Hormones; D013256:Steroids; C012445:molt-inhibiting hormone; D003513:Cycloheximide; D007930:Leucine