New genetically homogeneous background for dystrophic mice and their normal counterparts.

A new type of genetically homogeneous dystrophic and comparable normal mice, from an F(1) hybrid cross between 129/Re-dy and C57BL/6J-dy, is now available as a result of a special breeding program. The clinical manifestations in these F(1) hybrid dystrophics correspond closely with those observed in 129/Re-dydy mice, and they give completely comparable results on a variety of research tests. They are, however, considerably healthier than previously available dystrophics, with a growth rate closer to normal and a greatly increased life-span.