STRAIN INFORMATION


Family Identifier
NMF261
Synonym(s)
Spnb4nmf261; A.B6 Tyr+-Spnb4qv-7J/J; JR#5098
Synopsis
The mutants have weak hind limbs, body tremor.
Gene Symbol
Spnb4 (View MGI Record)
Gene
spectrin beta 4
Allele Symbol
Spnb4nmf261 (View MGI Record)
Allele
neuroscience mutagenesis facility261
Abnormal Assay(s)
Assay: Overt movement/posture

   Domain(s): Visible Mutants ; Movement/Neuromuscular Function
Phenotype Description
This phenotype becomes visible at 4 weeks of age (+/- 0.4, n=14); the mutants are smaller than their littermates and have difficulty supporting their weight on their hind limbs, which they drag intermittently. Mobility is limited but the mice are able to move around slowly. When the mice are lifted by their tail, the hind limbs may show typical extension intially but then are quickly clasped to the body. Male or female mutants have been produced, however, a colony has to be maintained through ovarian transplants. Mapping results showed NMF261 to be nonrecombinant with D7Mit266 +/- 5.5 cM (one-sided 95% confidence limit; n=19 affected, n=14 unaffected F2); however, further information was obtained through a complementation test with Spnb4 (spectrin beta 4, old symbol qv, Jax# 001769), i.e.the results of one heteozygote mating between NMF261 and Spnb4qv-lnd/J resulted in 2 affected mice in a total of 8 progeny, suggesting NMF261 to be an allele of Spnb4.   (View video)
Pathology Report
Standard pathology work-up on three mutants (43, 49, or 88 days of age) revealed no abnormalities; whole muscle mounts of the hind limb of the older mouse stained with fluorescent-labeled bungarotoxin, SV2, and SMI 31 also revealed no abnormalities.
HERITABILITY AND MAPPING INFORMATION
Background Strain
A.B6 Tyr+
Heritability Mode
Recessive
Heritability Status
Proven; 2 heterozygote x heterozygote matings resulted in 6 affected mice in a total of 31 progeny.
Chromosome
7
Molecular Interval
see Spnb4
Map
STATUS INFORMATION
Mutant Status
Cryopreserved Embryos
Comments
(13) NMF261 have been requested by and distributed to 3 investigators.
Contact e-Mail Address
nmf-mice@jax.org