Expression of heat-shock protein 70 kDa in Tetrahymena pyriformis during cell adaptation to salinity changes in the medium

The alteration of the content of heat-shock protein 70 kDa (Hsp70) was studied in cells of the freshwater ciliate Tetrahymena pyriformis after the salinity of the medium had been changed. It was shown that ciliates acclimated to fresh (0%) or salt (2 and 10%) water have similar levels of constitutive Hsp70. Neither pronounced induction nor a decrease in the Hsp70 level were revealed in ciliates after salinity stress. These data differ from the results we obtained previously with more euryhaline ciliates, Paramecium nephridiatum and P. jenningsi . In those species, we observed both the induced synthesis of Hsp70 after salinity stress and changes (decrease or increase) in the constitutive Hsp70 level after the acclimation of ciliates to the altered medium salinity. We presume that the differences in the chaperone system reaction of these ciliates species may be connected with their different salinity resistances, least of all in P. jenningsi , intermediate in T. pyriformis , and most pronounced in P. nephridiatum .