¹Institute of Cell Biology, School of Biology, University of Edinburgh, UK

Correspondence: J Terashima, Institute of Cell Biology, University of Edinburgh, D713, Darwin Building, Kings Buildings, Mayfield Road, Edinburgh, UK. Tel: +44(0) 131 650 5368; Fax: +44(0) 131 650 5371; E-mail: jun.terashima@ed.ac.uk

Received 23 November 2004; Revised 12 January 2005; Accepted 13 January 2005; Published online 18 March 2005.

Abstract

Egg chambers of Drosophila are reabsorbed under conditions of nutritional shortage by inducing apoptosis at stages 8 and 9, midway through oogenesis. Nutritional shortage leads to an increase in ecdysone concentration in flies. Apoptosis at stage 8/9 is also induced by 20-hydroxyecdysone injection into the females maintained with adequate nutrition. The expression pattern in the ovary of some ecdysone response genes, E75A, BR-C, is different according to the nutritional environment and the overexpression of these genes induces apoptosis. Apoptosis is suppressed by Juvenile hormone analog treatment of females under nutritional shortage. We predict nutritional and stress response genes control hormone levels and the increase in ecdysone concentration in the flies following starvation induces the ovarian apoptosis. We therefore used a microarray approach to identify the genes involved in receiving the nutritional signal from the environment and translating it in the ovary, thus initiating and executing apoptosis.