Expression of stress-related genes was investigated in the marine copepod Acartia tonsa in relation to heatshock at two different salinities (10 and 32‰),and it was furthermore investigated whether experimen-tally induced epibiont infestation led to elevated expression of stress-related genes.
Expression of thegenes ferritin, Hsp90 and Hsp70 were analyzed in adult copepods by conducting reverse transcription-quantitative real time PCR (RT-qPCR).
The expression of Hsp70 and Hsp90 was significantly up-regulatedafter heat shock and the expression levels were higher in copepods cultivated at 10‰ salinity seawaterthan in copepods cultivated at 32‰.
Significant up-regulation of ferritin (3.3 fold increase) was observedas a response to infestation with the epibiotic euglenid Colacium vesiculosum.
Results suggest that (i)A. tonsa responds more pronounced to thermal shock when cultivated in low salinity seawater (10‰)as compared to optimal salinity seawater (32‰) and (ii) epibiont infestation does cause a measureablephysiological response in the host.