Mice homozygous for the strigosus mutation are identifiable as early as six days of age by their elongated bodies and digits and a conical extension of the body at the base of the tail. Older mice are extremely thin and exhibit arachnodactyly, thoracic kyphosis, and, often, kinks in the tail. The strigosus mutation is milder than the longjohn alleles, which become humbacked at a younger age and have sacral kinks. Upon necropsy, homozygotes are found to lack normal body fat deposits. Skeletal analysis demonstrated delayed endochondral ossification, most obvious in the hind- and forepaws but affecting the entire skeleton. At embryonic day 10.5 all truncal vertebrae are present but enlarged.
The strigosus mutation arose in 1989 in an outbred stock after mutagenesis with ethylnitrosourea and was bred onto 129/Sv. A belted mutation was also present in this predominantly 129 stock when it was imported into The Jackson Laboratory from the laboratory of Jean Louis Guenet at The Pasteur Institute. Mice were intercrossed and maintained segregating for the strigosus mutation and in 1996 embryos were cryopreserved from homozygous males bred with either homozygous or heterozygous females. The unspecified belted mutation remains in this stock.
|Allele Type||Chemically induced (ENU)|
|Gene Symbol and Name||Npr3, natriuretic peptide receptor 3|
|Strain of Origin||Outbred|
|General Note||Genbank: AF131864|
|Molecular Note||A C-to-A transversion mutation at coding nucleotide 502 (c.502C>A) leads to a histidine to asparagine substitution (p.H168N) in a highly conserved region of the protein. Experiments in cultured cells indicate that the mutant protein is retained in the endoplasmic reticulum.|