Analysis of red blood cells from rainbow trout Oncorhynchus mykiss infected by Tetracapsuloides bryosalmonae

The myxozoan Tetracapsuloides bryosalmonae is the causative agent of proliferative kidney disease (PKD) – a disease of salmonid fishes, notably of the commercially farmed rainbow trout Oncorhynchus mykiss. Both wild and farmed salmonids are threatened by this virulent/deadly disease, which is often expressed by swollen kidneys. In order to understand the causes and consequences of the disease, we studied the immune response towards the parasite. To profile the influence of the disease on these cells, we produced a transcriptome of teleost RBCs in health and disease. Compared to erythrocytes originating from healthy fish, PKD fundamentally altered RBCs in their metabolism, adhesion, and response to inflammation. The aim of this work was to characterize the population of RBCs in PKD-diseased trout. We investigated the RBC-specific phenotype that may be a cause or a consequence of the anemia or hypergammaglobulinemia associated with PKD. To this end, we compared the RBC transcriptome of four healthy SPF versus four PKD-diseased rainbow trout using a salmonid-specific microarray.