First characterisation of the population and immune parameters of the hemocytes of the mussel Crenomytillus grayanus (Dunker, 1853)

Abstract

We first investigated the morphology and immunological activities of hemocytes of the mussel Crenomytilus grayanus using flow cytometry and light microscopy. Three types of hemocytes were identified in the hemolymph including granulocytes, hyalinocytes, and blast-like cells. Granulocytes were the most abundant (57.4%) cells in the hemolymph, followed by hyalinocytes (20.8%) and blast-like cells (5.3%). Flow cytometry revealed that the granulocytes are most active in the cell phagocytosis and oxidative activity. Hyalinocytes also exhibited a certain level of the phagocytic and oxidative activities but in a lesser extent than the granulocytes. In contrast, the blast-like cells showed no phagocytosis and tremendously low oxidative activity, indicating that this hemocyte in not actively involved in the cell-mediated immunological activity. In addition, hemocytes were subjected to acute temperature challenges (15, 20, 25 and 30 °C) and their immune-related functions analyzed. Our results showed that relative high temperature (25 and 30 °C) represent a stressful condition for the mussel C. grayanus, as depicted by a low phagocytosis capacity after 4 hours exposure.es, hyalinocytes, and blast-like cells. Granulocytes were the most abundant (57.4%) cells in the hemolymph, followed by hyalinocytes (20.8%) and blast-like cells (5.3%). Flow cytometry revealed that the granulocytes are most active in the cell phagocytosis and oxidative activity. Hyalinocytes also exhibited a certain level of the phagocytic and oxidative activities but in a lesser extent than the granulocytes. In contrast, the blast-like cells showed no phagocytosis and tremendously low oxidative activity, indicating that this hemocyte in not actively involved in the cell-mediated immunological activity. In addition, hemocytes were subjected to acute temperature challenges (15, 20, 25 and 30 °C) and their immune-related functions analyzed. Our results showed that relative high temperature (25 and 30 °C) represent a stressful condition for the mussel C. grayanus, as depicted by a low phagocytosis capacity after 4 hours exposure.