Changes in the ultrastructure and glycoproteins of the cyst wall of Colpoda cucullus during resting encystment

our previous studies on long-term resting encystment of Colpoda inflata showed transcriptional activity of the macronucleus and the occurrence of protein synthesis. in this work we have investigated the structure, the glycoprotein composition, and the lectin-binding site localization of the cyst wall of C cullus at increasing cyst ages, by means of scanning and transmission electron microscopy, confocal microscopy, and cytochemical and lectin blotting techniques. During an 18-day resting encystment, the cyst wall undergoes structural modifications resulting in the compaction of its previously-formed layers and the production of new material that is placed on the inner side of the cyst wall. Changes in the localization of ConA-/WGA-binding sites have been checked by comparing 7-day-old cysts to 1-day-old ones. Moreover, differences in the electrophoretic and ConA-/WGA-positive patterns have been found in 18-day-old cysts when compared to 1-day-old ones. The results of in vivo ConA and WGA assays suggest that ConA promotes encystment and delays excystment.