dde homozygotes have disproportionate dwarfing evident at birth by shortened limbs, although the axial skeleton appears normal. The back feet have fused toes. Retinal dysplasia presents as white lines in the retina and electroretinaograms show abnormal rod and cone function. Males are sterile and females are poor breeders and poor mothers, often requiring foster mothers to rear the pups. The lifespan of homozygotes varies with some dying shortly after wean and others surviving to approximately one year of age. Ailments identified in homozygotes include emphysema, stomach polyp, apoptitic cells of the tesis, thyroid cysts, holes in the thoracid chord white matter, and holes in the skeletal muscle fibers in the leg. While it has been proposed that dde may offer a model for Walker-Wardburg syndrome, this has not yet been proven.
The disproportionate dwarf and eye defect mutation arose spontaneously in the CByJ.Cg-hop/J strain (stock 002718) in 2000 when that strain was at backcross generation N5. This mutant subline has been maintained by sibling inbreeding and the hop sterile phenotype has not been seen since the initial separation of the strains so is believed to have been bred out of this mutant subline.
|Allele Name||disproportionate dwarf and eye defect|
|Gene Symbol and Name||dde, disproportionate dwarf and eye defect|
|Strain of Origin||CByJ.Cg-Ttc26hop/J|
|Molecular Note||This spontaneous mutation was identified at The Jackson Laboratory.|
Homozygous females are often poor mothers and foster mothers are needed to support the pups. Meal should be added into the cage so that it is accessible to the homozygous dwarf pups and these pups should be housed with the parents longer than the usual 3 weeks prior to wean.
When using the disproportionate dwarf and eye defect mouse strain in a publication, please cite the originating article(s) and include JAX stock #010822 in your Materials and Methods section.