[Expression of stress proteins of family HSP70 in response to cold in Myrmica ants from different geographic populations].

Expression of HSP70 is induced by stress factors, including sub-lethal chilling, but the role of HSP70 for overcoming consequenses of cold stress is not clear. If the role is positive, the level of HSP70 expression might be higher in populations from colder climates. By use of immunoblotting we investigated dynamics of HSP70 expression in response to cold stress in two Myrmica species from three localities of different latitude (50, 60 and 67 degrees N). The results showed that in the more thermophilic species Myrmica rubra expression of HSP70 after cold stress was more intense. Expression traits within both species did not show direct relationship with latitude. In M. rubra the southernmost population and in M. ruginodis the northernmost one displayed the fastest and most intense response. However, in M. rubra the two other studied populations were similar in timing and intensity of the response, while in M. ruginodis the intermediate population showed the slowest and weakest response. The data suggest that the expression of HSP70 might play the most considerable role in the adaptation to cold in the southernmost population of M. ruginodis.