The tortoise shell mutation (Atp7aMo-to) arose spontaneously in a non-inbred obese stock in 1952 at the Jackson Laboratory. A pair of obese heterozygotes on a miscellaneous background produced a single tortoise shell appearing female which was mated to a normal appearing male sibling. A tortoise shell female offspring was mated to a C57BL/6J male and the stock was then sibling mated using tortoise shell females bred to wildtype males since tortoise shell males die before birth. The stock was at F17 in 1960. It was taken by Dr. Elizabeth Russell and then backcrossed onto the C57BL/6J background. It was cryopreserved in 1979 by mating tortoise shell females at N79-88 to C57BL/6J males. The stock was refrozen in 1984 by mating tortoise shell females at N86 from the frozen embryo repository to C57BL/6J males.
|Gene Symbol and Name||Atp7a, ATPase, Cu++ transporting, alpha polypeptide|
|Strain of Origin||obese stock|
|General Note||Atp7aMo-to, tortoiseshell, semidominant. Arising spontaneously in an obese stock, the tortoiseshell mutation was considered to be a mottled locus allele because of its interaction with other alleles at the locus and because it shows about the same linkage relation with Zic3 (bent tail) as Atp7aMo (J:13382). Heterozygous females resemble Atp7a/+ females in color. The vibrissae are slightly wavy and the coat has a slightly silky texture. The distribution of patches of wild-type and white color is different from the distribution of patches of wild-type and wavy hair, suggesting that Atp7aMo-to probably acts independently in melanoblasts and hair follicles (J:15324). Most hemizygous males die before birth (J:24988), but a few are stillborn (J:12963). Using as parent a male presumed to be chimeric for Atp7aMo-to/Y and +/Y, Grahn et al. (J:12963) showed that homozygous Atp7aMo-to/Atp7aMo-to and heterozygous Atp7aMo-to/Atp7aMo-dp females die in utero, while heterozygous Atp7aMo-to/Atp7aMo-blo and Atp7aMo-to/Atp7aMo-br females reach term, but die by 15 days of age. The elastic lamina of the aorta is defective in stillborn hemizygous Atp7aMo-to males and in 40 per cent of Atp7aMo-to/+ female heterozygotes.|
|Molecular Note||A spontaneous mutation that arose at The Jackson Laboratory in 1952.|
When maintaining a live colony, these mice can be bred as heterozygous females and wildtype males (the gene is X linked), or or to C57BL/6J inbred mice (Stock No. 000664). Hemizygous males and homozygous females are not viable.
When using the B6.Cg-Atp7aMo-to/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #000053 in your Materials and Methods section.