Stress response for disease control in aquaculture

Abstract

Heat shock proteins (Hsps) are robustly induced by diverse stressors that denature proteins. In addition to stress resistance, Hsps are involved in the folding of nascent proteins, plant and animal development, aging, environmental adaptation and the immune response, demonstrating the fundamental importance of these proteins to cell survival. Heat shock proteins are induced in aquatic organisms by perturbations of temperature and salinity, environmental contaminants, handling, hormones and biotic stressors. Exposure to sublethal stress may enhance tolerance to a subsequent stress, a process termed induced thermotolerance, and provide protection to stressors other than the initial stress, known as cross-tolerance. In the present review, we briefly describe the established approaches that are used to control disease during aquaculture. This is followed by documentation of Hsp induction after exposure to stressors commonly encountered by aquatic organisms. Induced thermotolerance, cross-tolerance and immune enhancement by Hsps are also considered. Although physiological stress is known to decrease disease resistance it is now becoming clear that stress-induced Hsps enhance the tolerance of aquatic organisms to disease. Potential applications for Hsps in the commercial production of fish, crustaceans and molluscs are indicated, an issue of significance when the importance of aquaculture in feeding the world's population is realized

Analysis of immune-related ESTs and differential expression analysis of few important genes in lines of rohu (Labeo rohita) selected for resistance and susceptibility to Aeromonas hydrophila infection

“…A significantly lower expression of Hsp70 was detected in resistant line fish in this current study with second generation resistant line fish on the contrary to higher expression noticed in our earlier study [16]. Up-regulation of Hsp70 is an indicator of stress [50]. Although fish of both lines were grown under the same environmental conditions one explanation might be that susceptible fish experience more stress than resistant fish under the same environmental condition and Hsp70 might be responded to that unknown stress more profusely in susceptible line fish.…”

“…Under normal physiological conditions these proteins mediate nascent protein folding and assembly, translocate proteins through membranes into organelles such as mitochondria and assist the degradation of structurally aberrant proteins through ATP independent processes [50]. However, an induced expression was always noticed in stressed conditions such as heat, toxins and disease in order to refold the irreversibly denatured proteins to prevent cell from damage.…”

The ecology, evolution, impacts and management of host–parasite interactions of marine molluscs

“…In some instances, abiotic factors interact to influence the production and activity of enzymes associated with cellular defenses (e.g., Akberali and Trueman, 1985;Jenny et al, 2002;Edge et al, 2012;Soudant et al, 2013). Sublethal multi-stressor impacts can be evaluated in molluscs using a suite of 'subtle' cellular biomarkers, including heat shock proteins (e.g., Akberali and Trueman, 1985;Ringwood et al, 1999Ringwood et al, , 2002Sung et al, 2011;Edge et al, 2012).…”

Hydration/dehydration cycles imposed on Artemia cysts influence the tolerance limit of nauplii against abiotic and biotic stressors

“…In experimental animals, induction of Hsp70 in response to exposure to abiotic and/or pathogenic biotic stressing agents has been shown to play an important role in conferring resistance to the animals against these stressors (Sung et al 2007(Sung et al , 2011a; Kiss et al 2011;Baruah et al 2013Baruah et al , 2014. For instance, in aquaculture animal models, induction of Hsp70 was associated with the protection of the animals against thermal challenge, viral attack, ammonia toxicity or transportation stress (for details, see review Roberts et al 2010;Sung et al 2011b).…”