Role of juvenile hormone in the synthesis and sequestration of vitellogenins in the red cotton stainer, Dysdercus koenigii (Heteroptera : Pyrrhocoridae)

Venugopal, KJ and Kumar, Dinesh (2000) Role of juvenile hormone in the synthesis and sequestration of vitellogenins in the red cotton stainer, Dysdercus koenigii (Heteroptera : Pyrrhocoridae). In: Comparative Biochemistry and Physiology - Part C: Pharmacology, Toxicology & Endocrinology, 127 (2). pp. 153-163.

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Abstract

Investigations were carried out to determine the role of juvenile hormone (JH) and 20-hydroxy ecdysone in the synthesis and uptake of vitellogenins, which were earlier identified, purified and characterised, in Dysdercus koenigii. The concentration(s) of vitellogenin(s) in fat body, haemolymph and that of vitellin(s) in ovary were significantly lower after chemical allatectomy at eclosion. In addition, at 70 h after emergence, chemical allatectomy reduced ovarian vitellin concentration, but vitellogenin levels remained normal in the fat body and haemolymph. The haemolymph vitellogenins were not incorporated into oocytes in such insects. Administration of JH-III at 20 h after allatectomy restored vitellogenin levels in the fat body and haemolymph, but the ovary failed to incorporate the available vitellogenins from haemolymph in such insects. However, when JH-III was administered twice, one at 20 h and then at 70 h after allatectomy, vitellogenin concentrations in fat body and haemolymph and also vitellin concentrations in ovary approached control levels. It is suggested that JH has two separate roles, one in vitellogenin synthesis and the other in uptake. 20-hydroxy ecdysone had no apparent role in either vitellogenin synthesis or uptake in D. koenigii. (C) 2000 Elsevier Science Inc. All rights reserved.

Item Type:	Journal Article
Publication:	Comparative Biochemistry and Physiology - Part C: Pharmacology, Toxicology & Endocrinology
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Corpora allata;Juvenile hormone;20-Hydroxy ecdysone; Dysdercus koenigii;Vitellogenin;Vitellin;Allatectomy; Precocene I;Heteroptera
Department/Centre:	Division of Biological Sciences > Centre for Ecological Sciences
Date Deposited:	23 Aug 2010 12:28
Last Modified:	19 Sep 2010 06:14
URI:	http://eprints.iisc.ac.in/id/eprint/31417

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