The Effect of Specific MHC Class I and Class II Combinations on Resistance to Furunculosis in Atlantic Salmon ( Salmo salar)

• Published in: Scandinavian Journal of Immunology
• Main Authors: Kjøglum, S., Larsen, S., Bakke, H. G., Grimholt, U.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2007
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1111/j.1365-3083.2007.02052.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-3083.2007.02052.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3083.2007.02052.x

Abstract The aim was to evaluate the performance of selected individual major histocompatibility complex (MHC) class I and class II alleles and combinations of these on disease resistance against furunculosis. The material, consisting of 2,145 Atlantic salmon ( Salmo salar ) from seven families, contained four MHC class I (UBA) alleles and two MHC class II alpha (DAA) alleles. The included alleles were previously shown to influence resistance towards furunculosis. The fish were challenged with the bacterium Aeromonas salmonicidae , causing furunculosis. The total mortality in the material was 84.0%, and both dead and surviving fish were genotyped for UBA and DAA. For MHC class II fish with DAA*0301 were more resistant than fish with DAA*0201 , which were significantly more susceptible ( P < 0.05). For MHC class I, the ranking of performance of the alleles differed from previous results, and fish with allele UBA*0601 were found to be most resistant while fish with UBA*0501, UBA*0201 and UBA*0301 were more susceptible. The analysis of combined MHC class I and class II genotype detected that fish with genotypes UBA*0501/*0501;DAA*0301/*0301, UBA*0601/*0601;DAA*0301/*0301 and UBA*0601/*0601;DAA*0201/*0201 were most resistant ( P < 0.05), while the genotypes associated with increased susceptibility were UBA*0501/*0501; DAA*0201/*0301 and UBA*0501/*0501;DAA*0201/*0201 ( P < 0.05). In addition, Cox regression analysis show that both family and MHC alleles contributed significantly to survival. Thus, in addition to reproducing the effect on resistance and susceptibility of many MHC class I and class II alleles individually, we also detected an effect of certain MHC class I and class II combinations suggestive of cross‐talk between the class I and class II pathways.