These Sema7a knock-out mice exhibit exhibit abnormal lateral olfactory tract outgrowth. They are suitable for use in studies of lateral olfactory tract development and axonal growth.
Vijaya Iragavarapu-Charyulu, Florida Atlantic University
The targeted Sema7a gene encodes a glycosylphosphatidylinositol (GPI)-anchored membrane glycoprotein that is involved in integrin-mediated signaling and immune response regulation.
Mice that are homozygous for the targeted mutation are viable and fertile. No gene product (mRNA) is detected by Northern blot analysis. By age embryonic day 16, homozygotes exhibit abnormal lateral olfactory tract outgrowth. The lateral olfactory tract (LOT) from mutants have a more narrow morphology when compared to wildtype controls. In many mutants, no LOT is detected in the most caudal regions. This mutant mouse strain may be useful in studies of lateral olfactory tract development and axonal growth.
In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.
A loxP- and FRT-flanked targeting vector containing a neomycin resistance gene driven by the mouse phosphoglycerate kinase promoter, exon 1 and 1.1kb of flanking sequence, was utilized in the construction of this mutant. The construct was electroporated into 129S6/SvEvTac derived MC1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric male mice were crossed to C57BL/6 mice, and then crossed to cre deleter strain, BALB/c-Tg(CMV-cre)1Cgn/J (STOCK#3465) to remove the floxed targeting vector. The mice were then backcrossed onto C57BL/6 for 6 generations. The Donating Investigator reports that it is possible that an additional cross to a non-C57BL/6 strain prior to the strain's shipment to The Jackson Laboratory may have occurred. The mice were then backcrossed to BALB/cJ for 10 generations. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize BALB/cJ oocytes (Stock No. 000651).
|Allele Name||targeted mutation 1, Alex L Kolodkin|
|Allele Type||Targeted (Null/Knockout)|
|Allele Synonym(s)||null- SEMA 7A; Sema7a-|
|Gene Symbol and Name||Sema7a, sema domain, immunoglobulin domain (Ig), and GPI membrane anchor, (semaphorin) 7A|
|Strain of Origin||129S6/SvEvTac|
|Molecular Note||A single loxP site remained in place exon 1 as well as 1.1 kb of upstream DNA. The deleted exon includes the start codon and encodes 59 residues which comprise the entire signal sequence.|
|Mutations Made By|| |
R. Jeroen Pasterkamp, University Medical Center Utrecht
When maintaining a live colony, these mice can be bred as homozygotes.
When using the Sema7a KO on BALB/cJ mouse strain in a publication, please cite the originating article(s) and include JAX stock #029373 in your Materials and Methods section.