The ornithine aminotransferase deficiency caused by this spontaneous point mutation generally permits homozygotes to survive to adulthood and reproduce, but they have hyperornithinemia, are smaller than normal, have delayed fur development, and develop chorioretinal degeneration, providing a model for gyrate atrophy of the choroid and retina. This is a much less severe phenotype than that caused by a null allele, which causes all homozygotes to die by 48 hours after birth.Read More +
This autosomal recessive mutation is characterized by smaller mice that have delayed fur development. At birth mutants are the same size as littermates, but at one-week of age mutants are smaller and appear hairless compared to controls. At two weeks of age mutants have no hair compared to littermates with a full coat. Mutants gradually regain size and fur and are similar to normal littermates by 10 weeks of age, but can be identified by the ruffled appearance of their fur (due to the irregular directions and patterns of hair growth). They can be identified later by white at the tips of their hair.
Because histology of retinas from 7- and 12-month-old homozygous Oatrhg mice revealed chorioretinal degeneration, mice of this strain may offer a model for gyrate atrophy of the choroid and retina (GACR) in humans.
The retarded hair growth mutation arose spontaneously in the AKR/J inbred strain at The Jackson Laboratory in the mid-1970s. This was maintained initially by sibling intercross, then with intermittent backcrossing to AKR/J. In 1997 an outcross was done to C57BL/6JEi and the line was been maintained by sibling inbreeding with one subsequent backcross and sperm was cryopreserved from homozygous males at approximately generation N2F4 in 2000
|Allele Name||retarded hair growth|
|Allele Type||Spontaneous (Hypomorph, Humanized sequence)|
|Gene Symbol and Name||Oat, ornithine aminotransferase|
|Strain of Origin||AKR/J|
|Molecular Note||A spontaneous G-to-C transversion in exon 9 causes a glycine to alanine substitution at amino acid 353 (p.G353A), an evolutionarily conserved residue. This glycine is mutated in at least one family with gyrate atrophy of the choroid and retina.|
Homozygotes are weaned up to 2 weaks later than their wild-type siblings because of their size. Powdered food is added to the cage floor for the homozygotes.
When using the retarded hair growth mouse strain in a publication, please cite the originating article(s) and include JAX stock #003544 in your Materials and Methods section.