Homozygous us mice can be distinguished at birth by small size and a kinky tail. Skeletal abnormalities also include split arches and fusions in cervical vertebrae, fusions in thoracic and lumbar vertebrae and unilateral and bilateral fusions of one or more ribs. Delayed growth, sterility, kidney abnormalities, and abnormalities of the urogenital system also occur. Affected mice appear to have a thinner hair coat with fewer zigzag hairs and narrower awls than normal and slightly abnormal behavior. The human mutation Nail-patella-syndrome (NPS1) maps to the region of human Chr 9 (9q34) that is homologous to the us region of mouse Chromosome 2. Phenotypic similarities between the two syndromes suggest the possibility that they are caused by mutations at homologous loci.
The us mutation occurred in a linkage cross at The Jackson Laboratory in 1966. The strain was cryopreserved in 1983.
|Gene Symbol and Name||a, nonagouti|
|Strain of Origin||old mutant of the mouse fancy|
|General Note||Insertion of the LV30 retrotransposon without the beta4 retrovirus sequence does not cause the nonagouti phenotype. J:278039|
|Molecular Note||Characterization of this allele shows an insertion of DNA comprised of a 5.5kb virus-like element, VL30, into the first intron of the agouti gene. The VL30 element itself contains an additional 5.5 kb sequence, flanked by 526 bp of direct repeats (beta4 retroviral sequence). The host integration site is the same as for at-2Gso and Aw-38J and includes a duplication of four nucleotides of host DNA and a deletion of 2 bp from the end of each repeat. Northern analysis of mRNA from skin of homozygotes shows a smaller agouti message and levels 8 fold lower than found in wild-type.|
|Allele Name||urogenital syndrome|
|Gene Symbol and Name||us, urogenital syndrome|
|Strain of Origin||STOCK Tgm3we Atrnmg a|
|General Note||The mutation has been proposed as a model for human nail-patella-syndrome (OMIM 161200; J:14466).|