PERITROPHIC MATRIX OF THE BLACK FLY SIMULIUM-VITTATUM - FORMATION, STRUCTURE, AND ANALYSIS OF ITS PROTEIN-COMPONENTS

The peritrophic matrix (PM) (same as peritrophic membrane) is secreted by the midgut epithelium of insects and completely surrounds the inge sted food. The PM is likely to influence disease transmission by hemat ophagous insects. As a prelude to a more detailed examination of PM fu nction, we report on morphological. and molecular studies of the PM ty pe 1 (PM1) from Simulium vittatum. The blood meal induces major change s in epithelial cell morphology: cells become flattened, microvilli de crease dramatically in number, and organelles redistribute in the cyto plasm. The PM1 forms within minutes of the blood meal. After 6 h the P M1 has reached its maximum thickness (approximately 13 mu m) and stren gth. Two-dimensional gel electrophoresis reveals two major PM1-specifi c proteins of 66 and 61 kDa. Synthesis of these PM1 proteins is likely to be induced by the blood meal, since they are not detectable prior to blood feeding. The time course of accumulation and disappearance of the PM1 proteins closely correlates with the appearance and disappear ance of the PM1 itself. (C) 1994 Wiley-Liss, Inc.