Major Histocompatibility Complex Variation and Haplotype Associated Survival in Response to Experimental Infection of Two Bd-GPL Strains Along a Latitudinal Gradient

While both innate and adaptive immune system mechanisms have been implicated in resistance against the chytrid fungus Batrachochytrium dendrobatidis (Bd) , studies on role of specific MHC haplotypes Bd infection are rare. Here, we studied variation Class IIB loci common toad Bufo bufo along a latitudinal gradient across Sweden. In general, Swedish populations had few diversity declined from south (13 haplotypes) to north (four haplotypes). The low may compromise ability northern fight emerging disease, such as . laboratory experiment, infected newly metamorphosed toads with two strains Global Pandemic Lineage ( -GPL) compared survival sham controls. -infected lower Moreover, was dependent -strain -mediated than southern individuals. toads. All experimental animals were monomorphic for single haplotype, whereas found seven different animals. toads, haplotype suggesting differential dynamics depending host characteristics.