Vitelline membrane biogenesis in Drosophila requires the activity of the alpha-methyl dopa hypersensitive gene (I(2)amd) in both the germline and follicle cells.

Abstract

The vitelline membrane of Drosophila eggs is composed of a family of proteins which are cross linked into an insoluble matrix with an overlying waxy layer that prevents desiccation. We present here three sets of experiments which show that integrity of the vitelline membrane requires the activity of the alpha methyl dopa hypersensitive (I(2)amdH or amd) gene in both egg chambers and follicle cells. We show that loss of amd activity either by dietary administration of inhibitors or in genetic mosaics of either the germ line or follicle cells leads to production of defective vitelline membranes and by in situ hybridization, that amd is expressed in both nurse cells and follicle cells. The amd gene product is the first non-structural protein gene described whose activity is required for vitelline membrane biosynthesis. Given its unique role in insects and its demonstrated sensitivity to dietary inhibitors, the amd gene product poses an attractive target for insect control.