ENCYSTMENT AND EXCYSTMENT IN COLPODA-INFLATA - MACRONUCLEAR DNA AND TOTAL PROTEIN-CONTENT QUANTITATIVE VARIATIONS

Cell activities have been investigated in Colpoda inflata strain Na 17 , during transition to resting cyst and in the course of a long-lastin g encystment, as well as after the first hours following excystment in duction. In order to reveal the synthesis both of macronuclear DNA and cell proteins, macronuclear DNA and total protein contents were cytof luorometrically measured in starved pre-cystic organisms, in just form ed and in increasingly older cysts, up to 50 days since encystment ons et, and, in 5 to 25 days old cysts, after 5 hours from excystment indu ction. The results suggest that starved cells are able to enter restin g encystment at different phases of their cell cycle. Furthermore, not only do macronuclear DNA and protein syntheses take place during tran sition to the cyst, but also in cysts as old as 27 days. Investigation s on the dynamics of excystment indicate that a high chromatin extrusi ng activity occurs in the macronuclei of excysting cells, after the 70 % of the excystment time. Conversely, after only the first quarter of the excystment time, proteins would be utilized possibly to reorganiz e cortical structures of the excysting cell.