MHC haplotype (RT1.BaDa) of PVG.R23 was transferred onto the genetic background of KDP/Tky strain (RT1.BuDu). This allele has been maintained in heterozygous condition. Backcrossing has started since 2003 and afterwards maintained by sib mating
The rats homozygous for the RT1u/u develop diabetes frequently similar to that of KDP rats (RT1u/u). RT1a/u heterozygous rats develops diabetes with low frequency. RT1a/a homozygous rats do not develop diabetes. Both RT1a/u and RT1a/a rats exhibit thyroidititis