engleski

Heat shock protein (Hsp70) expression in two congeneric Mediterranean limpets – how much is too much stress?

Patella rustica and Patella caerulea are two congeneric limpet species, both occurring along the rocky shores of the Mediterranean but on different tidal heights. P. rustica is dominant in the upper intertidal zone while P. caerulea is more abundant in the lower part of the same zone. To investigate the relationship between their physiological thermal tolerance and intertidal zonation, heat - shock protein (Hsp70) levels were measured under simulated thermal conditions in the laboratory. Hsps are molecular chaperones that stabilize proteins and detect those that are irreversibly damaged under stressful conditions and as such play an important role in the protection of cellular level functioning. Two experiments were set to test the hypothesis that the lower zoned P. caerulea will have a reduced Hsp70 expression patterns as compared to the higher zoned, and supposedly more tolerant, P. rustica. First experiment was designed to investigate the response of limpets to different heating rates and the second to different thermal regimes. Hsp70 detection was performed using Western blot with Hsp70 specific antibody (polyclonal hrHsp70). The obtained results did not support starting hypothesis, since there was no significant interspecific differences in Hsp70 and the effect of different thermal regimes. Hence, it is likely that these limpets' species already posses enough Hsps constitutive levels as one of the primary „defense strategies“. Although occupying different vertical zones with regard to tidal range, these species seems to be experiencing similar habitat temperatures and the acute thermal stress they were exposed to in the laboratory was not enough to cross their thermotolerance threshold for inducement of higher levels of Hsps.

limpets; heat stress; heat shock proteins

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