ON THE TRYPSIN SENSITIVITY OF GAMETE CONTACT AT FERTILIZATION AS STUDIED WITH LIVING GAMETES IN CHLAMYDOMONAS

¹ Florida State University, Institute for Space Biosciences, Tallahassee, Florida 32306

Trypsin affects the copulation of isogametes in Chlamydomonas (Chlorophyceae) in two ways. In low concentrations it rapidly suppresses pair formation by interfering with the formation of the protoplasmic bridge between the gynogamete and the androgamete. In the early phase of its formation the bridge may even be split by the action of trypsin. In higher concentrations, trypsin additionally affects the mating type reaction by destroying the capacity of the gynogametes to agglutinate with the androgametes. The agglutinating capacity of the androgametes is not impaired by trypsin. Trypsin does not affect the species specificity of the attachment mechanism within the system tested.