Sex-specific binding and inactivation of agglutination factor in Chlamydomonas eugametos.

Gametes of opposite mating type (mt (+) and mt (-)) of the green alga Chlamydomonas eugametos agglutinate via their flagella as a prelude to sexual fusion. To quantitate sexual agglutination, an in vitro assay has been developed using (35)S-labeled flagella and the isolated mt (-)agglutination factor. It is shown that not only isolated flagella, but also the mt (-)agglutination factor rapidly bind to the flagella of intact gametes of the opposite mating type.