Effect of starvation on the secretory product and the morphological appearance of the infoldings of basal plasma membrane of midgut cells of Drosophila auraria larvae.

Abstract

Short-time starvation (until 2 hrs) of Drosophila auraria larvae at the early third or mid-third instar affected the fine structure of the gastric ceca epithelial cells but had no effect on the cells of the anterior, middle and posterior midgut regions. In gastric ceca cells starvation produces: (1) an abrupt increase in the number of secretory granules, (2) dilation of the infoldings of basal plasma membrane, (3) decrease in the number of the openings by which the hemolymph communicates with these cells. Refeeding of the starved larvae reverses all these changes. After the 2 hrs starvation period, the number of the secretory granules produced by the gastric ceca and by the midgut cells decreased gradually. About 3-4 hrs of starvation the number of the secretory granules was less than that found in "normal fed larvae", but the cells continued the production of secretory granules until larval pupation.