The breeding stock for the Ames Dwarf colony was generously provided by Dr. Andrzej Bartke at Southern Illinois University School of Medicine. This mutant carries a recessive mutation in the Prop1 gene (Prop1df) and homozygous mice are dwarf and exhibit extended lifespan. Heterozygotes are normal in size. In the NIA mutant mouse aging colony, the Ames Dwarf mice are bred from a heterozygous female crossed to a homozygous mutant male. Therefore, one half of the offspring will be heterozygous and one half will be homozygous mutants. Normal sized control mice available from this colony will all be heterozygous. These mice are not genotyped as the homozygotes are clearly distinguished from heterozygotes by size.
Ames dwarf mice (Prop1df/Prop1df) have difficulty maintaining their body temperature so it is essential that they are housed with normal sized mice. They are housed with heterozygous (Prop1df/+) mice in the NIA colony and must also be shipped with normal sized mice and housed with normal sized mice upon receipt.
- Therefore, there is a requirement when ordering Ames Dwarf mice that at least one normal-sized control (heterozygote) must be ordered for each dwarf mouse (homozygote) ordered. There will be no exceptions to this requirement.
Other husbandry issues are that a 6% fat diet is better for the dwarf mice than a 4% fat diet and powdered food should be placed in the bottom of the cage.
This colony is under development and the numbers available are very small.
Masternak MM, Al-Regaiey K, Bonkowski MS, Panici J, Sun L, Wang J, Przybylski GK, Bartke A. Divergent effects of caloric restriction on gene expression in normal and long-lived mice . J Gerontol A Biol Sci Med Sci. 2004 Aug;59(8):784-8.