Survival curve modified through dietary restriction (DR) in male Donryu rats

It is well known that dietary restriction (DR) can prolong the life of certain inbred strains of laboratory rodents. This prolongation can be usually shown in a survival curve in parallel to that of non-DR groups. On an outbred strain, Donryu, however, DR resulted in a unique pattern of survival curve. In DR group, the first three quarters of male rats survived longer in a form parallel to non-DR, while the last quarter of them survived far longer in a quite different shape from controlled group. DR may select animals that are capable of longer survival within Donryu. The selection of a quarter animal indicates the parameter for selection may be regulated by a single recessive locus.