Anti-HSP70 monoclonal antibody, clone 6B6

The yellow drum (Nibea albiflora; Na) constitutes an important seafood fish species that is subjected to intensive cage culture in China. The fish is susceptible to infection by bacteria and virtual pathogens, which results in considerable economic loss. In the present study, the pathogenic characteristics and immune response of the yellow drum were analyzed after Pseudomonas plecoglossicida or poly I:C challenge. Tissue sections revealed cell vacuolization in the liver and obvious macrophage infiltration in the spleen following P. plecoglossicida infection, whereas these tissues exhibited no significant lesions upon poly I:C challenge. Superoxide dismutases (SODs) and heat shock proteins (HSPs), which play important roles in the immune response of fish in defense against environmental threats or stresses, were further analyzed. The quantitative real time PCR (qPCR) analysis showed that mRNAs for intracellular copper/zinc-SOD (NaSOD1), manganese SOD (NaSOD2), extracellular copper/zinc-SOD (NaSOD3), HSP70, and HSP90 were expressed in 11 tested tissues including high levels in the liver, spleen, kidney, and gill; further significant increase was observed in the liver, spleen, and gill following P. plecoglossicida or poly I:C challenge. Moreover, the activities of total SOD and the contents of NaHSP70 and NaHSP90 in the liver were up-regulated after P. plecoglossicida or poly I:C challenge, which was generally similar to the fluctuations of mRNA expression in the tissue. The results showed that the dynamic changes in SODs and HSPs exhibited a similar tendency, which might indicate a coordinate action against P. plecoglossicida or poly I:C challenge. These findings will contribute towards better understanding of the biological process involved in defending against pathogenic bacteria and virtual challenge, as well as provide insight regarding the molecular mechanisms of the initial immune response in the yellow drum.

The intertidal mussel B. rodriguezii is a representative species from hard bottom substrates where both anthropogenic and natural stressors are present. Pre-exposure to these different stressors can modify the tolerance to additional stressors such as warming. Moreover, this tolerance can vary depending on intraspecific variables such as the organism's sex. The effects of warming and its intraspecific variability in representative coastal species are crucial to understanding the tolerance to future environmental scenarios. The mussels were collected in different environmental scenarios, including low (Control), chemical (Harbour) and natural stressed (Estuary) sites, and then exposed to different water temperatures (10-30 degrees C) for 14 days. Lethal and sublethal responses were evaluated in different mussel populations. Thus, cumulative death rate, air survival time, heat shock proteins (HSC70/HSP70), total ubiquitin, catalase (CAT), glutathione-s-transferase (GST) and lipid peroxidation (TBARS) were assessed in mussels from different areas and different sexes. The results revealed diminished air survival time and high cumulative mortality rate in mussels collected at the harbour and those exposed to higher temperatures, respectively. The sublethal responses of the field animals showed different patterns according to the different areas investigated. Besides, the results revealed that these differences were also observed between sexes. Regarding the sublethal responses in mussels exposed to warming, the interactive effects of temperature and sites showed a strong influence on all biochemical parameters analyzed (p < 0.001). Therefore, harbour mussels showed a distinct pattern compared to other locations and reflecting the most damaging effects of warming. The influence of sex and its interactions with warming were also crucial in most of the sublethal responses (p < 0.05). Multivariate analysis was performed with all sublethal responses, and the different warming scenarios showed different groups according to the sites. In the predicted warming scenarios, males showed no differences between sites. In contrast to males, females showed differences between sites in the predicted and the worse-case warming scenarios. Our results highlight the importance of compensatory mechanisms in the mussel warming tolerance like HSP70. The influence of sex is also crucial in understanding warming tolerance in mussels chronically exposed to pollutants in their natural environment. Also, lethal endpoints are essential for understanding the non-reversibility signature of the observed biochemical responses.