These mice carry a spontaneous mutation at the Sptbn4 locus characterized by locomotor instability, pronounced quivering, deafness, varying degrees of paralysis of the hindlegs, clasping of the hindlegs when held up by the tail, and priapism in most males.Read More +
Mice homozygous for the quivering-Jackson spontaneous mutation (Sptbn4qv-J) are characterized by locomotor instability, pronounced quivering, deafness, varying degrees of paralysis of the hindlegs, clasping of the hindlegs when held up by the tail, and priapism in most males. Serial sections of the brain, cord, and nerve roots reveal no abnormalities, and urinary amino acids are normal. The inner ear is histologically normal and has normal thresholds for compound action potentials at the round window. However, the thresholds for potentials in the inferior colliculus are twice as high as normal, showing that the deafness, unlike that of any other deaf mutants in the mouse, is of central origin. Viability of homozygous mutant mice at weaning is normal, but the life span is short, the majority dying before 5 months of age. Males are sterile, but females may be fertile and nurse their young.
The spontaneous mutation quivering Jackson (Sptbn4qv-J) arose in The Jackson Laboratory vibrating (Pitpnavb) strain when it was at generation F40 in 1974. The vibrating mutation arose in strain DBA/2J and was outcrossed once to C57BL/6J before inbreeding. The first affected Sptbn4qv-J female to breed was mated to a C3FeB6-A/Aw-J hybrid, and the stock was maintained by mating a quivering female to a C3FeB6-A/Aw male in the cross generation and sibling pairs in the intercross generation. It was cryopreserved in 1986 by mating heterozygous males to heterozygous females at N30.
|Allele Name||quivering Jackson|
|Gene Symbol and Name||Sptbn4, spectrin beta, non-erythrocytic 4|
|Strain of Origin||D2XB-Pitpnavb|
|Molecular Note||This spontaneous mutation was proven allelic with the original quivering mutation by a noncomplementation test. Sequencing of the Spnb4 gene only detected three silent third-base polymorphisms in the coding region and these polymorphisms can be identified in unaffected inbred strains.|
|Allele Name||wild-type agouti|
|Allele Synonym(s)||dark-bellied agouti|
|Gene Symbol and Name||a, nonagouti|
|Strain of Origin||various|
|General Note||The A allele is usually regarded as a wild-type allele. For example,the C3H and CBA mouse sublines are homozygous for agouti. Hairs are black with a subapical yellow band. This black-yellow-black pattern is referred to as agouti. The general appearance is yellowish brown, slightly lighter on the belly than on the back.|
|Molecular Note||This allele, often referred to as wild-type, comprises a novel 131 amino acid protein encoded in a gene comprising four exons, three coding, spanning 18kb. Unique changes in this gene account for all other alleles that have been molecularly characterized. The expression of this allele is almost always dominant to other alleles of this gene.|