A Comparative Study of the Binding of Two Lectins in the Early Development of the Freshwater Sponge, Ephydatia mulleri

Carbohydrates have been implicated in cell adhesion and in developmental processes. Lectin histochemistry using ConcanavalinA and Lotus lectin was used to localize lectin-accessible mannosyl and fucosyl residues in a maturing sponge developing from histoblasts generated during germination of a gemmule. With the exception of cystencytes found in the sponges stained with Lotus lectin, a similar staining pattern was seen with the two lectins, but there was a rather significant difference in the intensity of staining. This difference in staining intensity was thought to be a result of either more mannosyl residues available to the lectin or that the concentration of mannosyl residues in Ephydatia mulleri is greater than the concentration of fucosyl residues.