Induction of the Insect Vitellogenin In Vivo and In Vitro
It has been documented for several species of insects belonging to different orders that the predominant yolk protein precursor, or vitellogenin, is synthesized by an extraovarian tissue, namely the fat body, of the female. The fat body produces this female specific protein and exports it into the hemolymph, from which it is taken up by the growing oocytes via pinocytosis. Vitellogenins from the fat body are immunologically identical to those of the fully grown eggs (see Engelmann and Ladduwahetty, 1974). The juvenile hormones (JH) are found to direct vitellogenin synthesis in all species studied in detail with the exception of the Saturniid moths (Telfer, 1965) and presumably Aedes aegypti (Hagedorn, 1974). In Leucophaea, the three known naturally occurring JHs can direct the de novo synthesis of vitellogenin in vivo (Engelmann, 1971). Analysis of the dose-response relationship showed that JH III, presumably the species’ own JH, was least effective. In this species, as well as in others, JH appears to be an essential rate-limiting component for vitellogenin synthesis.
KeywordsJuvenile Hormone Cell Free System Orotic Acid Nascent Polypeptide Sucrose Density Gradient Centrifugation
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- Engelmann, F., 1974b, Amer. Zool. 14: 1195.Google Scholar
- Engelmann, F., 1976, Coll. Intern. Centre Nat. Rech. Sci. Paris (in press).Google Scholar
- Engelmann, F., and Ladduwahetty, M., 1974, Zool. Jahrb. Physiol. 78: 289.Google Scholar
- Engelmann, F., Friedel, T., and Ladduwahetty, M., 1976, Insect Biochem. (in press).Google Scholar
- Hagedorn, H.H., 1974, Amer. Zool. 14: 1207.Google Scholar
- Niessing, J., Schnieders, B., Kunz, W., Seifert, K.H., and Sekeris, C.E., 1970, Z. Naturforsch. 25b: 1119.Google Scholar
- Tata, J.R., 1973, Karolinska Symp. Res. Meth. Reprod. Endocrinol. 6: 192.Google Scholar