These mice express Cre recombinase under the control of the myelin protein zero (P0) (Mpz) gene. P0 is a glycoprotein located in Schwann cells of the peripheral nervous system (but not in sensory neurons). Defects in Schwann cells lead to nerve cell demyelination and have been associated with Charcot-Marie-Tooth disease and Dejerine-Sottas disease. Cre-recombinase expression is seen primarily in Schwann cells, and to a lesser extent in a small number of periventricular cells that give rise to cells in the cortex. Expression is also seen in a subpopulation of neural-crest derived progenitors in the heart. Homozygotes are viable and fertile. When crossed with a strain containing a loxP site-flanked sequence, Cre-mediated recombination results in deletion of the flanked sequence in Schwann cells between embryonic days 13.5 and 14.5.
For example, when bred to a strain expressing a floxed-Beta1 integrin (Bint1) gene, the resulting mice exhibit tremor, abnormal gait, paw clenching and defects in radial sorting of axons by Schwann cells and altered myelination. Analysis of BINT1 expression shows that recombination occurs in Schwann cells, but not in dorsal root ganglion neurons (Feltri et al., J Cell Biol. 2002).
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.
