Insect Vitellogenesis in Juvenile Hormone-dependent Species
نویسندگان
چکیده
In most insects, vitellogenesis is regulated by juvenile hormone (JH). The recent cloning of the vitellogenin gene in a number of JH-dependent species has allowed the study of the induction of vitellogenin production by JH at a molecular scale. Potential JH response elements have been described in the regulatory regions of vitellogenin and other JHinducible genes. These elements may not only shed some light on the early molecular mechanisms of JH action, but also may help to characterise the JH receptor, which is the major goal in this research field.
منابع مشابه
The effect of ovary implants on juvenile hormone production by corpora allata of male Diploptera punctata
In the cockroach Diploptera punctata, vitellogenic basal oocytes stimulate juvenile hormone production by the corpora allata. Experiments with males were designed to determine whether oocytes must grow vitellogenically in order to stimulate juvenile hormone production. Two ovarioles with vitellogenic basal oocytes were implanted into unoperated and sham-operated males that do not produce vitell...
متن کاملTerpenoid omega-hydroxylase (CYP4C7) messenger RNA levels in the corpora allata: a marker for ovarian control of juvenile hormone synthesis in Diploptera punctata.
Ribonuclease protection assays were used to measure changes in allatal transcript levels of the CYP4C7 gene which encodes a cytochrome P450 terpenoid omega-hydroxylase thought to play a role in the metabolism of JH and its precursors. Denervation of the corpora allata does not affect the pattern of expression of the CYP4C7 gene. Transplantation experiments show that CYP4C7 mRNA levels are depen...
متن کاملInsulin signaling is necessary for vitellogenesis in Drosophila melanogaster independent of the roles of juvenile hormone and ecdysteroids: female sterility of the chico1 insulin signaling mutation is autonomous to the ovary.
It has been suggested that insulin signaling mutations of Drosophila melanogaster are sterile and long-lived because of juvenile hormone (JH) and ecdysteroid deficiency. However, female sterility of an insulin/IGF-like signaling mutant (chico(1)) of D. melanogaster is not mediated by downstream systemic signaling in terms of major alterations in JH or ecdysteroid levels. chico(1) is a null muta...
متن کاملEat to reproduce: a key role for the insulin signaling pathway in adult insects
Insects, like all heterotrophic organisms, acquire from their food the nutrients that are essential for anabolic processes that lead to growth (larval stages) or reproduction (adult stage). In adult females, this nutritional input is processed and results in a very specific output, i.e., the production of fully developed eggs ready for fertilization and deposition. An important role in this inp...
متن کاملEcdysteroids, Juvenile Hormone and Vitellogenesis in the Cockroach Leucophaea maderae.
Topical application of 400 micro g of the juvenile hormone analog, methoprene, to females of the penultimate instar of Leucophaea maderae failed to induce vitellogenin synthesis. However, last instar females showed an increasing response level in making vitellogenin as they aged during the first half of the instar. In the second half of the last instar the response to methoprene declined to nea...
متن کامل