Effect of poly I:C and LPS injection on immune responses of redclaw (Cherax quadricarinatus)

Redclaw (Cherax quadricarinatus) is a potential species for aquaculture. It is native to Australia and has beneficial attributes which enhance its suitability for aquaculture. This present study was attempted to investigate the protein expression in redclaw crayfish injected with poly I:C, LPS and PBS (control). Redclaw size of 13-20 gram were put into 60 litre glass aquaria, each aquarium consists of 4 animals. Tank 1 contains animals injected with Poly IC (2 mg/ml), tank 2 contains animals injected with LPS (10 mg/ml) and tank 3 contains animals injected with PBS (as control). Haemolymph and hepatopancreas of the animals were sampled and used for assay. Injection of Poly I:C and LPS resulted in the presence of inducible protein which express just below the 66.2 kDa marker on the gel electrophoresis, then suspected as Mx protein in crustaceans. Besides Mx protein, gel electrophoresis also expressed protein which has molecular weight between 31 and 45 kDa, which could be lipopolysaccharide and β-1,3-glucan binding protein (LGBP). Results from electrophoresis of redclaw hepatopancreas showed the expression of protein which was up-regulated by Poly IC but not by LPS. The protein was constitutively expressed in PBS-injected controls but an noted increase in expression was recorded in poly I:C stimulated animals.