Vitamin A deficiency: effect on mosquito eye ultrastructure.

Mosquitoes (Aedes aegypti) were reared aseptically for one generation on an artificial diet containing neither vitamin A nor its usual precursor in animals, betacarotene. Function (electrical response to light) in the compound eyes of these animals was severely impaired. Ultrastructure of the photoreceptor cells was abnormal in two respects: multivesicular bodies were absent, and masses of smooth membrane lamellae were present near the nucleus. The organization of the photoreceptor organelle, the rhabdomere, was normal. The eyes of control mosquitoes, to whose diet beta-carotene was added, were functionally and structurally normal. Multivesicular bodies were normally abundant and the perinuclear membrane masses were not present.