This strain expresses tamoxifen-inducible cre/ERT2 in high levels in mature olfactory sensory neurons and mature vomeronasal sensory neurons. It is valuable for the inducible expression or deletion of loxP-flanked alleles or reporters specifically in these neurons.
Peter Mombaerts, Max Planck Research Unit for Neurogenetics
Immunohistochemistry of the main olfactory epithelium, septal organ, and vomeronasal organ of heterozygotes shows wide Cre recombinase expression across the upper cell layers, co-staining with OMP and consistent with expression restricted to mature sensory neurons, but excluded from immature sensory neurons. This tamoxifen-inducible Cre allele has already been used to assess the survival of cohorts of olfactory and vomeronasal sensory neurons. By crossing to a cre-reporter, treating once with tamoxifen at E18.5, and counting reporter-expressing cells at various timepoints thereafter until 1 year of age, Holl (2018) found that the mean half-life for perinatally labelled olfactory sensory neurons is 26 days but also found that 7.8% of olfactory sensory neurons survive from E18.5 to 12 months of age. Holl also found that vomeronasal sensory neurons are more long-lived than olfactory sensory neurons, with no population decline from PD3.5 to 12 months of age.
The Omp coding sequence was replaced with cre/ERT2 and an FRT-flanked neomycin resistance cassette in 129P2/OlaHsd-derived E14 ES cells, yielding the Omptm12(cre/ERT2)Mom allele. A chimera was bred to 129S4/SvJaeSor-Gt(ROSA)26Sor
|Allele Name||targeted mutation 12.1, Peter Mombaerts|
|Allele Type||Targeted (Recombinase-expressing, Inducible, Null/Knockout)|
|Gene Symbol and Name||Omp, olfactory marker protein|
|Strain of Origin||129P2/OlaHsd|
|Molecular Note||The endogenous coding sequence was replaced by cre/ERT2 and the FRT-flanked neomycin resistance cassette was recombined out through breeding to a transgenic mouse expressing germline FLP1 recombinase.|
Mice homozygous for this null allele in Omp are subfertile, although they are reported to breed. Thus, it is best to maintain this strain by transmitting the mutation from heterozygotes. As this is a knockout allele and homozygotes are OMP-deficient, it is advisable to carry out experiments with heterozygotes.
When using the OMP-Cre-ERT2 mouse strain in a publication, please cite the originating article(s) and include JAX stock #018788 in your Materials and Methods section.