Limited MHC polymorphism in whales

Little is known about disease and genetic variation in aquatic mammalian species such as whales. In this paper human HLA class I and class 11 probes were used to study major histocompatibility complex (MHC) genes from two species of whale: Fin (Balaenoptera physalus) and Sei (B. borealis). Stronger signals were obtained on whale than on equivalent concentrations of mouse DNA. Evidence was obtained for severalDRB-related genes, aDNA gene, oneDQA gene, and multiple class I genes in whales. Interestingly, the whale genes, from the small panel studied, were less polymorphic than those of humans or mice. The aquatic environment of this mammalian species may be a unique factor in shaping its immune response through the MHC.