Rhodopsin Particles in the Photoreceptor Membrane of an Insect

Abstract

EM examination of freeze-fractured fly [Calliphora erythrocephala] retinae revealed the presence of particles 80-100 .ANG. in diameter, on the photoreceptor membrane. Flies which were raised on a vitamin-A deficient diet show a substantial reduction in the density of such particles. The reduction in particle density is in agreement with the reduction in visual pigment concentration as measured spectrophotometrically for these flies. The particles are probably identical with molecules of the visual pigment, rhodopsin. [Results are discussed in relation to Eledone and vertebrate photoreceptor membranes.].