Abstract
Naturaly occurring humoral lectins have been reported from wide range of animals, both invertebrates and vertebrates. In the case of invertebrate lectins, it has been postulated repeatedly that one of their biological functions is the recognition of self and nonself. Lectins may agglutinate and immobilize microbial or metazoan parasites. Furthermore, the immobilization could mediate subsequent phagocytosis or encapsulation of the parasite.
Humoral lectins of certain invertebrates, such as the giant clam Tridacna maxima and the acorn barnacle Megabalanus rosa, have been reported as the main constituents of hemolymph proteins. In addition, the content of the humoral lectins in M. rosa showed a seasonal variation. It is not readily acceptable from these experimental observations that in these invertebrates humoral lectins participate only in the recognition-function. M. rosa lectins have been recently demonstrated to show the inhibitory activity on the growth of calcium carbonate crystal. Possible multiple-functions of the humoral lectins in M. rosa are discussed especially in connection with the calcification.
