SOME ASPECTS OF THE STATE OF THE HEAT-SHO CK SYSTEM IN LIZARDS OF DIFFERENT ECOLOGICAL NICHES

We present a comparative analysis of the state and activation of the h eat shock factor (HSF) and expression of the main heat shock proteins (HSP68) in lizards occurring in ecological niches with different therm al parameters. The lizards of southern (Phrynocephalus interscapularis ) and northern origins (Lacerta vivipara) markedly differed according to the electrophoretic mobility of proteins normally binding to the re gulatory heat shock element (HSE). The heat shock (HS) effect is accom panied by the formation of an aggregated HSF form in both of the speci es, which is observed in the heat-resistant species (P. interscapulari s) to 49 degrees C. Analysis of constitutive (25 degrees C) HSE-bindin g complexes at normal and elevated temperatures, the data of mRNA-HSP6 8 northern hybridization, and immunological testing of HSF using speci fic polyclonal antibodies suggest the correspondence or noncorresponde nce of the observed constitutive HSE-binding complexes to the HSF-cons titutive form. The differential induction of HSP68 found in the specie s with different total contents of HSF and HSP68 suggests a correlatio n between these HS components. The results of experiments in nature su ggest that around the-clock oscillations of body temperature in P. int erscapularis during the hot season are coupled to parallel induction o f two main HSP 68 forms.