LECTIN-BINDING GLYCOCONJUGATES IN PARAMECIUM-PRIMAURELIA - CHANGES WITH CELLULAR AGE AND STARVATION

Lectins with different sugar specificities and binding to phagosome-ly sosome systems as well as cell surface constituents were used to study glycoconjugate variation throughout culture and clonal life in Parame cium primaurelia, particularly during the transition period from logar ithmic to stationary growth phase and in relation to clonal decline, r espectively These lectins include Griffonia simplicifolia agglutinin I I (GS II), Ricinus communis agglutinin (RCA(120)), Arachis hypogea agg lutinin (PNA), succinyl concanavalin A (succinyl-con A), and Triticum vulgaris agglutinin (WGA). The labeling obtained varies both according to the lectin used and to the culture and clonal age of the cells. Ne gative results were obtained in logarithmic growth phase cells and in clonal young cells by using lectin GS II. Conversely, lectins RCA(120) and PNA bind to the cell surface, the oral region as well as cilia, a nd do not undergo modifications with culture or clonal age and after p ermeabilization. WGA binds to constituents of the cell surface, tricho cyst tips, food vacuoles, the oral region, and cilia but the extent of labeling decreases as culture age increases; during clonal decline, c ells show the same labeling pattern as starved cells. Finally, the lec tin succinyl-con A shows a large amount of binding sites on the cell s urface, on trichocyst tips, and in the oral region of logarithmic-phas e cells, whereas the number of sites decreases in late stationary phas e. The data obtained partly differ from those reported in the literatu re and the differences can be attributed to the culture conditions and species examined. Nevertheless, the assumption that a rearrangement o f some glycoconjugates of membrane throughout culture and clonal life of Paramecium is confirmed.