Fig. 1. General features of Euplotes. Projection of optical sections passing through the ventral (A) or dorsal (B) surfaces of a cell decorated (in green) with anti-E antiserum directed against proteins of the alveolar plates (Williams et al., 1989), and decorated (in red) with the 20H5 antibody directed against centrins at the bases of the cilia (Sanders and Salisbury, 1994). On the ventral surface, clusters of cilia form the oral ciliature (OC) and the locomotory cirri (C); alveolar plates on this surface are irregular in shape. On the dorsal surface, the cilia are aligned into antero-posterior rows (in red), between which alveolar plates are regularly patterned.