Preconjugant cell‐cell interaction in the ciliate <i>Euplotes crassus</i>: A possible role of the ciliary ampules

Abstract

Abstract Euplotes crassus , like other species of Euplotes , possesses organelles commonly known as ampules, which are associated with the roots of cilia and organelles composed of cilia. Ampules of E. crassus greatly increase their functional activity during the cellular interaction which takes place after mixing cells of complementary mating type. Material is rapidly stored in the ampules, starting a few minutes after cell mixing, until a maximum of full ampules is reached in congregated cells which are closely approaching each other. Once the interacting cells have entered the agglutinative stages, the ampules show a dramatic decrease in their contents, so that cells just paired carry very few ampules filled by material. We infer that the material contained in the ampules has an important role in making the mixed cells competent to unite in pairs.