Folia Parasitologica 56[4] 251-258 (2009) | DOI: 10.14411/fp.2009.029

Response of rainbow trout (Oncorhynchus mykiss) in skin and fin tissue during infection with a variant of Gyrodactylus salaris (Monogenea: Gyrodactylidae)

Thomas R. Jørgensen, Martin K. Raida, Per W. Kania, Kurt Buchmann

Department of Veterinary Disease Biology, Laboratory of Fish Diseases, Faculty of Life Sciences, University of Copenhagen, Stig- bøjlen 7, 1870 Frederiksberg C., Denmark

Response mechanisms of rainbow trout Oncorhynchus mykiss (Walbaum), experimentally infected with a Danish strain of Gyrodactylus salaris Malmberg, 1957 were investigated using molecular tools (qPCR) and immunohistochemistry. Expression of ten immune-relevant genes and reactivity with five different antibodies in the epidermis of skin and fin tissue were analysed in susceptible but responding rainbow trout. Rainbow trout were susceptible with regard to the parasite strain which initially colonised fins but relocated to the body region as infection progressed. The ten investigated genes encoding the cytokines IL-1β, TNF-α, IFN-γ, IL-10 and markers for adaptive immune activity, such as CD-4, CD-8, TCR-α, IgM, IgT and MHC II, were not found significantly regulated during the course of infection although IFN-γ showed a slight up-regulation. Immunohistochemical analyses showed positive reactivity with antibodies against CD3, B-lymphocytes, neutrophilic granulocytes and collectin but not with mAb against IgM. No staining differences between infected and non-infected skin and fin tissue were detected.

Keywords: immune response, real-time PCR, immunohistochemistry, rainbow trout, Gyrodactylus salaris

Received: March 23, 2009; Accepted: August 4, 2009; Published: December 1, 2009  Show citation