These mice carry a spontaneous mutation at the Gulo locus characterized by decreased mobility, diminished weight gain, scruffy appearance, and bone defects.Read More +
The sfx phenotype is not apparent until shortly after weaning age. By 26-30 days of age, homozygotes display decreased mobility, diminished weight gain, and more scruffy appearance than their heterozygous or wildtype siblings. Dissection reveals smaller spleen and thymus and increased kidney and brain weights. A reduction in bone mass is accompanied by a paucity of mature osteoblasts on bone surfaces, a subtle reduction of chrondrocytes in epiphyseal-plate columns, growth plate arrest in long bones, and other architectural abnormalities. Bone analysis shows sponteneous fractures both in large bones and smaller ones such as metacarpals. Serum analysis shows a decrease in calcium, inorganic phosphate, alkaline phosphatase, osteocalcin, and insulin-like growth factor 1. These homozygotes also have a reduction in the number of both the red and white blood cells. Homozygotes are fragile and must be handled with great care. (Beamer et al., 2000.)
The sfx mutation arose spontaneously in the BALB/cBy-scat/Brk strain in 2000. The sfx-bearing strain was backcrossed to BALB/cBy, removing the scat mutation. This strain has subsequently been maintained via ovary transplant backcross-intercross using BALB/cByJ as the backcross partner.
|Allele Name||spontaneous fracture|
|Gene Symbol and Name||Gulo, gulonolactone (L-) oxidase|
|Strain of Origin||BALB/cBy-Rasa3scat|
|General Note|| |
This spontaneous mutation appeared in a BALB/cBy-scat colony at The Jackson Laboratory. The scat and sfx mutations were separated from each other by backcrossing BALB/cBy-scat mice to BALB/cBy mice and observing F2 offspring for those that exhibited the sfx phenotype but not the scat phenotype.
|Molecular Note||The mutation in the sfx mouse is a deletion that includes the entire Gulo gene.|
When using the spontaneous fracture mouse strain in a publication, please cite the originating article(s) and include JAX stock #004317 in your Materials and Methods section.