title: Biosynthesis and regulation of two vitellogenins in the fat body and ovaries of Ceratitis capitata (Diptera).
abstract: In adult female Ceratitis capitata both fat body and ovaries synthesize two vitellogenins (Vg-1 and Vg-2) with the same molecular masses as the respective vitellins of the eggs. Furthermore, both tissues contain two abundant mRNAs which yield, in a cell-free system, two previtellogenin polypeptides with molecular masses approximately 1,000 daltons higher than the mature Vgs. In vivo and in vitro studies during development suggested co-ordinate synthesis of Vg-1 and Vg-2 in each tissue. Also, at least in the fat body, Vg synthesis appears to be regulated at the level of transcription. Although both Vg-1 and Vg-2 are synthesized in the fat body and ovaries synchronously, their relative synthetic rates differ in the two tissues. The ratio of Vg-1 to Vg-2 synthesis in the fat body is approximately twice the respective ratio in the ovaries. Adult C. capitata males do not synthesize Vgs; however, they do so after treatment with 20-hydroxyecdysone.
authors.affiliation: Division of Genetics, Cell and Developmental Biology, Department of Biology, University of Patras, Patras, Greece.
authors.forename: Maria D
authors.initials: MD
authors.lastname: Rina
authors.affiliation: Division of Genetics, Cell and Developmental Biology, Department of Biology, University of Patras, Patras, Greece.
authors.forename: Anastassios C
authors.initials: AC
authors.lastname: Mintzas
keywords: Ceratitis capitata; Vitellin; Vitellogenin