This strain is homozygous for Cdh23ahl, the age related hearing loss 1 mutation, which on this background results in progressive hearing loss with onset prior to three months of age.
ALS/LtJ (Stock No. 003072) and ALR/LtJ inbred strains are of interest to investigators across a wide range of scientific disciplines including type 1 and type 2 diabetes, obesity, metabolism and toxicology research. Treatment of alloxan or streptozotocin causing pancreatic beta cell destruction, leads to severe hyperglycemia and hypoinsulinemia in ALS/LtJ mice. ALR/LtJ mice are resistant to these toxins. ALR/LtJ mice are of particular interest to investigators studying the immunogenetics of NOD/ShiLtJ mice in that the ALR/LtJ MHC haplotype (H2gx) is a variant of the diabetogenic NOD H2g7 haplotype. The (H2gx) haplotype is identical to the H2g7 haplotype from the H2-K end of the complex through the class II and class III region distal to Hsp70. However, at the distal H2-D end of the complex, ALR/LtJ mice have a rare H2-Dgx allele. Despite the similarities to the NOD/ShiLtJ mice, ALR/LtJ mice do not develop type 1 insulin dependent diabetes and thus provide an important control strain for NOD/ShiLtJ. ALR/Lt islets are unusually resistant in vitro to beta cell selective toxins known to generate free radicals (alloxan and streptozotocin). In addition, ALR/Lt islets are resistant to cytokine-mediated destruction. This resistance is correlated with an ALR strain-specific systematic elevation of enzymes and molecules associated with dissipation of free radicals. ALR/Lt mice of both sexes not treated with alloxan exhibit normal glucose tolerance, but gain weight rapidly, with females exhibiting male-like weight at 50 weeks of age. Understanding the genetic basis for the resistance of ALR mice to free radical mediated stressors, like alloxan and streptozotocin, as well as to immune system mediated stress, should prove valuable to pharmacologists interested in a variety of autoimmune and other diseases in which reactive oxygen species are associated with pathology.
Alloxan is a pancreatic beta cell-selective toxin that induces diabetes in rodents by generating cytotoxic free radicals. The ALR (alloxan-induced diabetes-resistant) inbred strain was created in Japan by selective inbreeding of Crj:CD-1 (ICR) mice with selection for resistance to diabetes development after administration of alloxan at doses representing the ED50 for the original Crj:CD-1 strain (45 mg/kg in males, 47 mg/kg in females). These dosages are lower than what is necessary to elicit a strong diabetogenic response in most inbred strains, typically 60mg/kg. After a litter was born and weaned, the parents and some of the progeny were alloxan-treated to select for low versus high [ALS (alloxan-induced diabetes-susceptible)] incidence lines based on blood glucose levels at 7 days post treatment. ALS and ALR inbred strains were obtained from Japan by Dr. EH Leiter (Lt) at The Jackson Laboratory in 1996. ALS/Lt and ALR/Lt mice were transferred to the production colony in 1998. Genome wide scan demonstrated that ALR/LtJ mice are not only closely related to ALS/Lt mice, but also to two other ICR-derived inbred strains selected for diabetes susceptibility and distributed by The Jackson Laboratory: NOD/LtJ and NON/LtJ.
|Allele Name||age related hearing loss 1|
|Allele Synonym(s)||Cdh23753A; mdfw|
|Gene Symbol and Name||Cdh23, cadherin 23 (otocadherin)|
|Strain of Origin||multiple strains|
|Molecular Note||Genetic complementation tests have shown allelism between the mdfw (modifier of deaf waddler) locus and the ahl locus. Further analysis has shown this is caused by a G to A transition at coding nucleotide position 753 of Cdh23 (SNP rs257098870). This hypomorphic allele changes splice donor site G-GT to A-GT, causing frame skipping of exon 7. This is predicted to delete part of the 2nd and 3rd ectodomains and cause reduced message stability. Twenty-seven strains classified with ahl and carrying the 753A allele include: CD-1, RBF/DnJ, PL/J, AKR/J, RF/J, BALB/cBy, A/WySnJ, P/J, SENCARA/PtJ, DBA/1J, ALS/LtJ, C58/J, C57BLKS/J, 129P1/ReJ, C57BR/cd, SKH2/J, BUB/Bn, MA/MyJ, LP/J, 129X1/SvJ, NOR/LtJ, A/J, C57BL/6, NOD/LtJ, DBA/2J, ALR/LtJ, C57L/J. Strains classified with ahl that DO NOT carry this mutation include: 129S1/SvImJ, C3H/HeSnJ, I/LnJ, YBR/Ei, MRL/MpJ.|
|Allele Name||mutation 2|
|Gene Symbol and Name||mt-Tr, mitochondrially encoded tRNA arginine|
|Strain of Origin||various|
|General Note||This polymorphism is present in ALR/Lt, NOD/ShiLtDvs, and SKH2/J. A variant with 10 adenines is found in A/J, ALS/Lt, NOD/ShiLtJ and NZB/B1NJ.|
|Molecular Note||The adenine repeat in the D stem is polymorphic with 9 adenines in this allele.|