In vivo effect of Neuropeptide F on ecdysteroidogenesis in adult female desert locusts (Schistocerca gregaria)

Van Wielendaele, Pieter; Wynant, Niels; Dillen, Senne; Badisco, Liesbeth; Marchal, Elisabeth; Vanden Broeck, Jozef

doi:10.1016/J.JINSPHYS.2013.03.005

Title

In vivo effect of Neuropeptide F on ecdysteroidogenesis in adult female desert locusts (Schistocerca gregaria)

Author

Van Wielendaele, Pieter

Wynant, Niels

Dillen, Senne

Badisco, Liesbeth

Marchal, Elisabeth

Vanden Broeck, Jozef

Abstract

Neuropeptides are important regulatory factors that mediate key life processes, both in vertebrates and invertebrates. Many insect neuropeptides display pleiotropic activities, which means that they can influence multiple aspects of insect physiology. In the fruit fly, Drosophila melanogaster, Neuropeptide F (NPF) mediates diverse physiological processes, such as learning, stress responses, feeding and male courtship behavior. In locusts, only a truncated form of the predicted "full-length" NPF, the nonapeptide "trNPF", has been isolated. This nonapeptide previously proved to be biologically active, since it was shown to influence food intake and weight increase, as well as oocyte growth in adult female desert locusts (Schistocerca gregaria [Forskal]). In the present study, we have further analyzed the effect of trNPF on female reproductive physiology in S. gregaria. We confirmed that daily trNPF injections in adult females elicit an increase of oocyte size. In addition, an RNAi-mediated knockdown of the Schgr-NPF precursor transcript in adult female locusts resulted in the opposite effect, i.e. significantly smaller oocytes. Moreover, we discovered that daily injections of trNPF in adult female S. gregaria, caused higher ecdysteroid titers in the ovaries and accelerated the appearance of ecdysteroid peaks in the hemolymph of these animals. The RNAi-based knockdown of the Schgr-NPF precursor transcript clearly resulted in reduction of both hemolymph and ovarian ecdysteroid concentrations, confirming the stimulatory effects of trNPF injettions on adult female etclygtereid leVeTS. The ObServe-d re-sults are disctiss-e-d in relation to previous reports on NPF activities in locusts and other insects. (C) 2013 Elsevier Ltd. All rights reserved.

Language

English

Source (journal)

Journal of insect physiology. - Oxford

Publication

Oxford : 2013

ISSN

0022-1910

DOI

10.1016/J.JINSPHYS.2013.03.005

Volume/pages

59 :6 (2013) , p. 624-630