These mice possess loxP sites on either side of exons 2 and 3 of the targeted gene. Mice that are homozygous for this allele are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. When used in conjunction with a Cre recombinase-expressing strain, this strain is useful in generating tissue-specific mutants of the floxed allele.
For example, when crossed to a strain expressing Cre recombinase in neuronal and glial cell precursors (see Stock No. 003771), this mutant mouse strain may be useful in studies of neurogenesis.
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 site flanked targeting vector containing a neomycin resistance gene under the control of the phosphoglycerate kinase, PGK, promoter was utilized in the construction of this mutant. This selection cassette was inserted downstream of exon 3 of the targeted gene, and another loxP site was inserted upstream of exon 2. This construct was electroporated into 129 derived embryonic stem (ES) cells which were transiently transfected with a Cre recombinase vector to remove the selection cassette. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric animals were crossed to C57BL/6 mice, then crossed to another mutant strain. The other mutant allele was subsequently bred out of the line. These mice carry only the conditional floxed mutant allele and arrived on a mixed B6;129 background (as Stock No. 006933). Mice from that colony were then backcrossed to C57BL/6J for multiple generations to generate this congenic strain (Stock No. 007003).
|Allele Name||targeted mutation 1, Paul S Knoepfler|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Allele Synonym(s)||Mycnloxp; Mycntm1Rne; NmycFl; N-mycFL|
|Gene Symbol and Name||Mycn, v-myc avian myelocytomatosis viral related oncogene, neuroblastoma derived|
|Strain of Origin||129|
|Molecular Note||Sequence encompassing exons 2 and 3 was flanked by a single loxP site upstream and a floxed neo cassette downstream. RT-PCR analysis revealed a 25% to 30% reduction in the amount of transcript in homozygous mutant mice.|
|Mutations Made By|| |
Paul Knoepfler, UC Davis Genome Center
Mutant mice were bred to C57BL/6J mice to generate this congenic strain. When maintaining a live congenic colony, these mice may be bred as homozygotes.
When using the B6.129-Mycntm1Psk/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #007003 in your Materials and Methods section.