| Summary: | Catalase is a crucial enzyme of the antioxidant defense system responsible for the maintenance of cellular redox homeostasis. The aim of the present study was to evaluate the molecular regulation of catalase (<i>Hdh-CAT</i>) in stress physiology, innate immunity, testicular development, metamorphosis, and cryopreserved sperm of Pacific abalone. <i>Hdh-CAT</i> gene was cloned from the digestive gland (DG) of Pacific abalone. The 2894 bp sequence of <i>Hdh-CAT</i> had an open reading frame of 1506 bp encoding 501 deduced amino acids. Fluorescence <i>in situ</i> hybridization confirmed <i>Hdh-CAT</i> localization in the digestive tubules of the DG. <i>Hdh-CAT</i> was induced by different types of stress including thermal stress, H<sub>2</sub>O<sub>2</sub> induction, and starvation. Immune challenges with <i>Vibrio</i>, lipopolysaccharides, and polyinosinic–polycytidylic acid sodium salt also upregulated <i>Hdh-CAT</i> mRNA expression and catalase activity. <i>Hdh-CAT</i> responded to cadmium induced-toxicity by increasing mRNA expression and catalase activity. Elevated seasonal temperature also altered <i>Hdh-CAT</i> mRNA expression. <i>Hdh-CAT</i> mRNA expression was relatively higher at the trochophore larvae stage of metamorphosis. Cryopreserved sperm showed significantly lower <i>Hdh-CAT</i> mRNA expression levels compared with fresh sperm. <i>Hdh-CAT</i> mRNA expression showed a relationship with the production of ROS. These results suggest that <i>Hdh-CAT</i> might play a role in stress physiology, innate immunity, testicular development, metamorphosis, and sperm cryo-tolerance of Pacific abalone.
|
|---|