Sexual mating of the biflagellated green alga Chlamydomonas eugametos is initiated by flagellar adhesion. This is followed by the formation of vis-a-vis pairs in which two cells of opposite mating type are connected by a slender cytoplasmic bridge. This neck slowly widens and, finally, zygotes are formed. Vis-d-vis pair formation was reversibly inhibited by cysteine. This effect was only observed when cysteine was present during the first few minutes of mating. Cysteine specifically prevented the protrusion of a plasma papilla between the flagellar bases; other early mating reactions tested were not affected. When cysteine was added to vis-d-vis pairs, the neck did not widen. It is argued that cysteine inhibits an autolysin with a protease character involved in dissolving the cell wall between the flagellar bases during early mating and in widening the neck of vis-d-vis pairs.

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Acta botanica neerlandica

CC BY 3.0 NL ("Naamsvermelding")

Koninklijke Nederlandse Botanische Vereniging

M.R. Samson, F.M. Klis, & H. van den Ende. (1988). Cysteine as a fusion inhibitor in the sexual mating reaction of the green alga Chlamydomonas eugametos. Acta botanica neerlandica, 37(3), 351–361.