Mice homozygous for the spastic spontaneous mutation (Glrbspa) can usually be recognized at 14 days of age, but some mutant mice may not be reliably distinguished until 5 or 6 weeks of age. They show spastic symptoms in response to handling, but spastic behavior can occur spontaneously. The spasms consist of rapid tremor, stiffness of posture, and difficulty in righting when placed on the back. No anatomical pathology occurs in either muscle or the central nervous system, except that herniated intervertebral discs and cysts of the leptomeninges occur, most severely in the lumbar region, possibly resulting from traumatic injuries sustained during the myoclonic episodes. The spastic symptoms can be markedly alleviated by intraperitoneal injection of aminooxyacetic acid, an inhibitor of g-aminobutyric acid transaminase (GABA-T), but not by Dilantin or trimethadione. Glycine receptor expression in the CNS of spastic mice is reduced to 20%, or less, of normal.
Genetic Background | Generation |
---|---|
|
Allele Type | Gene Symbol | Gene Name |
---|---|---|
Spontaneous | a | nonagouti |
Allele Type | Gene Symbol | Gene Name |
---|---|---|
Spontaneous | Glrb | glycine receptor, beta subunit |
Mice homozygous for the spastic spontaneous mutation (Glrbspa) can usually be recognized at 14 days of age, but some mutant mice may not be reliably distinguished until 5 or 6 weeks of age. They show spastic symptoms in response to handling, but spastic behavior can occur spontaneously. The spasms consist of rapid tremor, stiffness of posture, and difficulty in righting when placed on the back. No anatomical pathology occurs in either muscle or the central nervous system, except that herniated intervertebral discs and cysts of the leptomeninges occur, most severely in the lumbar region, possibly resulting from traumatic injuries sustained during the myoclonic episodes. The spastic symptoms can be markedly alleviated by intraperitoneal injection of aminooxyacetic acid, an inhibitor of g-aminobutyric acid transaminase (GABA-T), but not by Dilantin or trimethadione. Glycine receptor expression in the CNS of spastic mice is reduced to 20%, or less, of normal.
The spastic mutation (spa) arose spontaneously in the early 1960's at The Jackson Laboratory in a hybrid stock belonging to C. F. Chai that was produced by intercrosses of 6 inbred strains: C57BL/6J, C57BR/cd, A/J, BALB/c, LG and SM. This B6C3Fe-a/a stock of spastic was begun in 1973 by mating a B6.Cg-spa homozygous female at generation N5F5 to a C3H/Gn-a/a male and intercrossing the offspring. A homozygous female from the intercross was then crossed to a B6C3Fe-a/a F1 male and this stock was maintained through this cross-intercross using B6C3Fe-a/a F1 for the cross. In 1997 embryos were generated for cryopreservation by mating heterozygotes at generation N47.
Allele Name | nonagouti |
---|---|
Allele Type | Spontaneous |
Allele Synonym(s) | |
Gene Symbol and Name | a, nonagouti |
Gene Synonym(s) | |
Strain of Origin | old mutant of the mouse fancy |
Chromosome | 2 |
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 | spastic |
---|---|
Allele Type | Spontaneous |
Allele Synonym(s) | spa |
Gene Symbol and Name | Glrb, glycine receptor, beta subunit |
Gene Synonym(s) | |
Strain of Origin | Not Specified |
Chromosome | 3 |
Molecular Note | The mutation in the spastic mouse is an insertion of a 7.1 kilobase LINE-1 element within intron 6 of the gene. Glrb mRNA is markedly reduced throughout brains of homozygous mice, and was shown to be aberrantly spliced. |
When using the spastic mouse strain in a publication, please cite the originating article(s) and include JAX stock #000241 in your Materials and Methods section.
Facility Barrier Level Descriptions
Service/Product | Description | Price |
---|---|---|
Homozygous for a, Heterozygous or Homozygous or Wild-type for Glrb<spa> |
Terms are granted by individual review and stated on the customer invoice(s) and account statement. These transactions are payable in U.S. currency within the granted terms. Payment for services, products, shipping containers, and shipping costs that are rendered are expected within the payment terms indicated on the invoice or stated by contract. Invoices and account balances in arrears of stated terms may result in The Jackson Laboratory pursuing collection activities including but not limited to outside agencies and court filings.
The Jackson Laboratory has rigorous genetic quality control and mutant gene genotyping programs to ensure the genetic background of JAX® Mice strains as well as the genotypes of strains with identified molecular mutations. JAX® Mice strains are only made available to researchers after meeting our standards. However, the phenotype of each strain may not be fully characterized and/or captured in the strain data sheets. Therefore, we cannot guarantee a strain's phenotype will meet all expectations. To ensure that JAX® Mice will meet the needs of individual research projects or when requesting a strain that is new to your research, we suggest ordering and performing tests on a small number of mice to determine suitability for your particular project. We do not guarantee breeding performance and therefore suggest that investigators order more than one breeding pair to avoid delays in their research.
What information were you hoping to find through your search?
How easy was it to find what you were looking for?
We may wish to follow up with you. Enter your email if you are happy for us to connect and reachout to you with more questions.
Please Enter a Valid Email Address
Thank you for sharing your feedback! We are working on improving the JAX Mice search. Come back soon for exciting changes.