Transcriptomic profiling of the adaptive and innate immune responses of Atlantic salmon to Renibacterium salmoninarum infection. Transcriptomic profiling of the adaptive and innate immune responses of Atlantic salmon to Renibacterium salmoninarum infection

Renibacterium salmoninarum is a Gram-positive, intracellular bacterial pathogen that causes Bacterial Kidney Disease (BKD) in Atlantic salmon (Salmo salar). To identify Atlantic salmon genes responsive to R. salmoninarum pathogen, fish were intraperitoneally injected with R. salmoninarum (BKD) or sterile KDM-2 medium (control). Head kidney samples were collected at 13 days post-infection. Using 44K microarray analysis, transcriptome analysis was performed to identify differentially expressed probes in response to different levels of R. salmoninarum infection. Overall design: Atlantic salmon (54 ± 6 g) in the BKD group were injected with live R. salmoninarum, whereas fish in the control group were injected with sterile KDM-2 medium. The head kidney samples were collected at 13 days post-infection. The infection level of samples was determined using a TaqMan qPCR assay, and fish (n=5) with no (Control), high (H-BKD) or low (L-BKD) infection level were subjected to microarray analyses. Test samples were labeled with Cy5, whereas the common reference (i.e. a RNA pool of all 15 samples included in microarray experiment) was labeled with Cy3. Each individual test sample was hybridized together with the common reference sample on an array (i.e. 15 arrays in total). variable: Control: Control1, Control2, Control3, Control4, Control5. variable: L-BKD: L-BKD1, L-BKD2, L-BKD3, L-BKD4, L-BKD5. variable: H-BKD: H-BKD1, H-BKD2, H-BKD3, H-BKD4, H-BKD5. biological replicate: Control: Control1, Control2, Control3, Control4, Control5. biological replicate: L-BKD: L-BKD1, L-BKD2, L-BKD3, L-BKD4, L-BKD5. biological replicate: H-BKD: H-BKD1, H-BKD2, H-BKD3, H-BKD4, H-BKD5.