Demonstration by lectin cytochemistry of rod and cone photoreceptors in the lamprey retina.

Lectin cytochemical analysis was undertaken to examine the distribution of glycoconjugates associated with the short and long photoreceptor cells in the lamprey retina. Concanavalin A bound preferentially to the outer segment region of the short cells. Wheat germ agglutinin bound weakly to both long and short cells. The outer segment regions of the long cells were stained intensely with peanut agglutinin. Pretreatment with neuraminidase to remove sialic acid resulted in decreased binding of wheat germ agglutinin throughout the retina and increased binding of peanut agglutinin to the outer segment region of the short cells and the region of myoid process of the long cells. These results suggest that there is a difference in the distribution of glycoconjugate residues between the long and short cells. A rod-like character of the short cell and a cone-like character of the long are tentatively discussed. Lectin-binding patterns in other retinal regions is also examined.