Physiological and proteomic responses to single and repeated hypoxia in juvenile Eurasian perch under domestication – Clues to physiological acclimation and humoral immune modulations

We evaluated the physiological and humoral immune responses of Eurasian perch submitted to 4-h hypoxia in either single or repeated way. Two generations (F1 and F5) were tested to study the potential changes in these responses with domestication. In both generations, single and repeated hypoxia resulted in hyperglycemia and spleen somatic index reduction. Glucose elevation and lysozyme activity decreased following repeated hypoxia. Complement hemolytic activity was unchanged regardless of hypoxic stress or domestication level. A 2D-DIGE proteomic analysis showed that some C3 components were positively modulated by single hypoxia while C3 up- and down-regulations and over-expression of transferrin were observed following repeated hypoxia. Domestication was associated with a low divergence in stress and immune responses to hypoxia but was accompanied by various changes in the abundance of serum proteins related to innate/specific immunity and acute phase response. Thus, it appeared that the humoral immune system was modulated following single and repeated hypoxia (independently of generational level) or during domestication and that Eurasian perch may display physiological acclimation to frequent hypoxic disturbances.