Con A Binds to the Membranellar and Somatic Cilia of Stentor and to the Developing Oral Primordium During Oral Regeneration¹

Abstract

Binding sites for Concanavalin A have been located in the ciliate Stentor coeruleus by utilizing FITC‐Con A and fluorescence microscopy. When both nonregenerating and regenerating Stentor are fixed prior to FITC‐Con A exposure, FITC‐Con A binds intensely to the cilia of the membranellar band and to the somatic cilia that cover much of the cell surface. No binding is observed between the ciliary rows. The FITC‐Con A also binds to the developing oral primordia of regenerating cells. Binding of FITC‐Con A in the early stages of regeneration (prior to stage 4) appears to be less intense than that in the later stages. Additional FITC‐Con A binding appeared as a granular fluorescence in the area of the developing buccal cavity beginning at about stage 4 and disappearing around stages 6–7. The presence of α‐D‐methyl mannoside prevented the binding of FITC‐Con A to either regenerating or nonregenerating cells. If nonregenerating Stentor are exposed to FITC‐Con A prior to fixation, the binding pattern is entirely different with the fluorescence primarily in the form of random, granular patches spread over much of the cell but with no binding to either type of cilia. These results demonstrate that membrane glycoproteins capable of binding Con A are located primarily in the membranellar and somatic cilia and in the developing oral primordia during oral regeneration in Stentor. Concanavalin A binding to these sites may be involved in the Con A‐induced inhibition of oral regeneration observed in earlier studies.

Lectin-binding glycoconjugates in Paramecium primaurelia : changes with cellular age and starvation

“…Therefore, lectins are employed in cytological studies of membrane structures, of the intracellular pathway of protein glycosylation, of membrane component maturation, and of changes occurring in glycoconjugates during differentiation, growth, and development (Sharon and Lis 1989). Lectins were also used in protozoa to study sugar involvement in oral regeneration (Maloney 1986(Maloney , 1988, intercellular recognition and conjugation (Frisch and Loyter 1977;Tsukii and Hiwatashi 1978;Lueken et al 1981;Watanabe et al 1981; Van Bell 1983;Millikin and Weiss 1984;Lueken and Oelgemöller 1985;Pape et al 1988; Wolfe and Feng 1988;Plümper et al 1995), secretory activity Haake-Bell and Plattner 1987), cell movement (Frisch et al 1976; Van-DenBrink and Kaneshiro 1983), and phagocytosis (Brown et al 1975;Scott and Hufnagel 1983). The presence and distribution of glycoconjugates on the outer surface of the plasma membrane and subcellular organelles (Golgi apparatus, nuclear membrane, food vacuoles, discoidal vesicles, lysosomes, and trichocysts) were studied in some species of Paramecium (P. tetraurelia, P. caudatum, and P. multimicronucleatum) tested in the logarithmic phase of growth (Suchard et al 1982;Allen et al 1988Allen et al , 1989.…”