A crayfish Ras gene is involved in the defense against bacterial infection under high temperature. Issue 86 (March 2019)

• Record Type: Journal Article
• Authors: Li, Ronghui; Bai, Suhua; Yang, Decui; Dong, Chaohua
• Is Part Of: Fish & shellfish immunology. Issue 86(2019)
• Page Start: 608
• Page End: 617
• Publication Date: 2019-03
• Subjects: High temperature -- Immunity -- Lipid peroxidation -- M-RAS protein -- Phenoloxidase -- Total antioxidant capacity; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2018.11.062
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Temperature is an important environmental factor influencing crustacean resistance to pathogen infection. However, the mechanism underlying immune regulation by temperature remains unclear in crustacean. Here, we report a Ras gene of crayfish (designated as PcRAS1 ) which is involved in immune regulation of crayfish under high temperature. PcRAS1 is induced by both high temperature and bacterial infection and the induction by bacterial infection is associated with temperature. Significant changes of PcRAS1 expression was observed at 32 °C and 24 °C after infection with Aeromonas hydrophila, but relative moderate alternation was found at 16 °C after challenged with A. hydrophila. PcRAS1 silencing significantly reduced crayfish survival from high temperature (32 °C and 24 °C) or bacterial infection at 32 °C, but there was no significant effect on survival from bacterial infection at 24 °C or 16 °C. Further analysis reveals that PO activity is reduced by high temperature or enhanced by bacterial infection. Moreover, both the decreased PO activity and the enhanced PO activity are affected by PcRAS1 expression. PcRAS1 silencing further reduces PO activity under high temperature and compromises the enhanced PO activity by bacterial infection. Lipid peroxidation (LPO) and total antioxidant capacity (TAC) are also involved in the responses to high temperature. LPO is enhanced by lower temperature. TAC is reduced by high temperature and TAC change resulting from high temperature is amplified by PcRAS1 silencing. These results collectively indicate that PcRAS1 is involved in immune regulation against bacterial infection mediated by temperature. Highlights: High temperature decreased the survival of crayfish infected with A. hydrophila. PcRAS1 was induced by both bacterial infection and heat stress. PcRAS1 is required for crayfish to survive bacterial infection and high temperature. PO is involved in immuneregulation mediated by PcRAS1 under high temperature. PcRAS1 silencing reduced total antioxidant capacity under heat stress.