These mice carry a spontaneous mutation at the Unc5c locus characterized by falling to the side, an irregular thickness of the cortex, and scrambled Purkinje and granule cells.Read More +
The cerebellum of mice homozygous for the rostral cerebellar malformation spontaneous mutation (Unc5crcm) is smaller with fewer folia, there are ectopic cerebellar cells in the midbrain, and abnormal neuronal migration. Homozygous mutant mice are ataxic and experience growth retardation early in life. Homozygous males usually do not breed.
The rostral cerebellar malformation mutation (rcm) arose spontaneously in the B6.C3- Pde6brd1 Hps4le/J stock recovered from cryopreservation at The Jackson Laboratory in 1989 at N40pF1. The stock was sibling mated for 2 generations then maintained by ovarian transplant-cross-intercross. The first cross used ovaries from a homozygous rcm female which were transplanted into a host that was then bred to a C57BL/6J male. The heterozygous offspring were intercrossed and an ovarian transplant was done from a homozygous female, then the host was bred with a C3HeB/FeJ-a/a male and their offspring intercrossed. Ovarian transplant was done from a resulting homozygyous female and the host was bred to B6C3Fe-a/a F1 which became the standard mate in the cross-intercross maintenance of this strain. In 1991 embryos were generated for cryopreservation by breeding N2 heterozygotes.
|Gene Symbol and Name||a, nonagouti|
|Strain of Origin||old mutant of the mouse fancy|
|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||rostral cerebellar malformation|
|Allele Synonym(s)||rcm; rcms|
|Gene Symbol and Name||Unc5c, unc-5 netrin receptor C|
|Strain of Origin||C57BL/6J-Hps4le|
|Molecular Note||The mutation underlying the mutant phenotype is a tandem duplication of an exon encoding amino acids 763-818. The transcript expressed from this allele contains an in-frame insertion that is predicted to result in a protein that contains an additional 55 amino acids in the cytoplasmic region.|