Activation in vitro of vitellogenin uptake by the oocytes of the mosquito, Aedes aegypti
Autor(es): Sappington, TW; Helbling, P; Koller, CN; Raikhel, AS
Resumo: A blood meal stimulates the ovaries of the mosquito, Aedes aegypti, to internalize vitellogenin from the haemolymph for storage as yolk, The nature of the stimulation is biphasic, with a pulsed factor from the head released within the first 5 min of feeding stimulating the first phase of uptake, and the continuous release of another head factor initiating the second phase. Using an in vitro assay of [S-35]-vitellogenin uptake by ovaries, we sought to determine the intracellular signalling pathways utilized by the ovaries during stimulation of both phases of uptake. The adenylate cyclase activators forskolin and ethanol produced a statistically significant increase in rate of uptake in previtellogenic ovaries to levels characteristic of first-phase activated ovaries. Forskolin also induced the second phase of uptake in ovaries that had been arrested in the first phase of uptake by decapitation of the mosquito within 5 min of ingesting blood. Initiation and up-regulation of the rate of vitellogenin uptake does not depend on new protein synthesis.
Palavras-Chave: Aedes aegypti; Receptor - Mediated endocytosis; Yolk protein; Second messenger; Adenylate cyclase
Imprenta: Physiological Entomology, v. 23, n. 2, p. 158-164, 1998
Identificador do objeto digital: 10.1046/j.1365-3032.1998.232068.x
Descritores: Aedes aegypti - Protein synthesis
Data de publicação: 1998
