STOCK stb + a/+ Fign^fi a/J

Stock number: 000312
Product name: fidget
Research areas: Developmental Biology Research, Neurobiology Research, Sensorineural Research

Description

These mice carry a spontaneous mutation at the Fign locus characterized by head tossing and circular running. Fidget mice also have insufficient growth of the retinal neural epithelium resulting in small eyes, and skeletal abnormalities, including pelvic girdle dysgenesis, skull bone fusions and polydactyly.

Detailed description

Mice homozygous for the fidget spontaneous mutation (Fign^fi) toss their heads from side to side and tend to run in circles. Homozygous fidgit mice are hypersensitive to sound in early life, but later lose hearing ability. Corneal lesions are common, and hind foot polydactylism occurs. The bony labyrinth is quite defective. Other abnormalities including small eyes, absence of lachrymal glands, dislocation of the hip, and displaced parafloccular lobes of the cerebellum. Viability of homozygotes is usually less than normal and fertility is poor. The STOCK is also carrying the stubby spontaneous mutation (stb). Homozygous stubby mice are recognizable at 4 or 5 days by a domed head and thick short tail. Adult stubby mice have shorter heads, bodies, and legs compared to wildtype mice. Most females are fertile but males do not breed. Male mice do produce normal numbers of motile sperm. Cartilage histology is within normal limits, but chondrogenesis stops earlier than in normal animals.

Development

The fidget mutation was discovered by Gruneberg in a heterozygous stock as reported in 1943 and eventually obtained by The Jackson Laboratory. The strain was cryopreserved in 1985 and again in 2003.

Allele

Symbol: a
Name: nonagouti
MGI accession ID: MGI:1855937
Generation method: Spontaneous
Marker symbol: a
Marker name: nonagouti
Chromosome: 2
Strain of origin: old mutant of the mouse fancy
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 a^t-2Gso and A^w-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.
General note: Insertion of the LV30 retrotransposon without the beta4 retrovirus sequence does not cause the nonagouti phenotype. J:278039

Allele

Symbol: stb
Name: stubby
MGI accession ID: MGI:1857056
Generation method: Spontaneous
Marker symbol: stb
Marker name: stubby
Chromosome: 2
Strain of origin: Not Specified

Allele

Symbol: Fign^fi
Name: fidget
MGI accession ID: MGI:1856870
Generation method: Spontaneous
Synonyms: fi
Marker symbol: Fign
Marker name: fidgetin
Chromosome: 2
Strain of origin: random-bred
Molecular note: The fidget mutation is due to a retrotransposon insertion in intron 2, interfering with normal RNA processing.