Changing of the HSP70 Content in the Baikal Endemic Sponges Lubomirskiidae Under Conditions of Hyperthermia

Baikal endemic sponges (Lubomirskiidae) make up the bulk of the benthos biomass of the lake. For the first time the changes in the content of HSP70 in response to elevated environment temperature were analyzed in three endemic species of Baikal sponges: Baikalospongia bacillifera (Dybowski, 1880), B. intermedia (Dybowski, 1880) and Swartschewskia papyracea (Dybowski, 1880). Interspecific variability of constitutive HSP70 level was revealed for representatives of the three analyzed Lubomirskiidae species. After exposure at 13 °С for 3 and 7 days opposite changes were noted in the amount of HSP70. Under conditions of hyperthermia the protein level decrease at Baikalospongia species, while at the S. papyracea HSP70 content slightly increased. The differences in the mechanisms of stress adaptation probably affect the thermal resistance of the species, as well as are evidence supporting their specific status.