Concanavalin A binding to Chlamydomonas eugametos flagellar proteins and its effect on sexual reproduction

Abstract
The relative amounts of Concanavalin A (Con A) bound by gamete and vegetative flagella of both mating types (mt + and mt -) of Chlamydomonas eugametos were determined using 125I-Con A. Con A agglutinated all cell types by cross-linking their flagella in a random manner. No correlation was found between the extent of Con A-binding and Con A-mediated isoagglutination. Con A inhibited the sexual interaction between gametes at various levels. In mt + gametes it blocked sexual agglutination, whereas in mt - gametes it prevented papillar fusion. By SDS-gel electrophoresis nine Con A-binding components were found to be present in flagella. However, it was not possible to allocate a role in sexual agglutination to any of these components since they were present in all cell types, including vegetative cells which are not able to sexually agglutinate.