Mice homozygous for this iDTR mutation are viable and fertile. These mice have the simian diphtheria toxin receptor (DTR; from simian Hbegf) inserted into the Gt(ROSA)26Sor (ROSA26) locus. Widespread expression of DTR is blocked by an upstream loxP-flanked STOP sequence. Of note, it has been the experience of The Jackson Laboratory that mice homozygous for the DTR, in the absence of Cre, are undersized at 3 weeks of age. We therefore recommend weaning these mice at ~4 weeks of age.
When bred to Cre recombinase-expressing mice, the STOP sequence is deleted in tissues where Cre is present, permitting DTR expression. Cells expressing DTR are rendered susceptible to ablation following Diphtheria toxin administration.
For example, when bred to a strain with a Cd19 null allele and expressing Cre recombinase during the B lymphocyte development (Stock No. 006785), this mutant mouse strain may be useful in studies of lymphocyte cell ablation.
When crossed to a strain expressing Cre recombinase in oocytes (see Stock No. 011062), this mutant mouse strain may be useful in studies of ovarian development.
When crossed to a strain expressing Cre recombinase in the pituitary and, at lower levels, in the testes (see Stock No. 011069), this mutant mouse strain may be useful in studies of metabolic dysfunction.
Of note, iDTR mice are also available on a BALB/cBy congenic background (as Stock No. 008040) and a NOD congenic background (as Stock No. 016603).
Of note, The Jackson Laboratory Repository also distributes RC::L-DTA mice (Stock No. 026944), which have Cre recombinase-dependent inverted tox176 attenuated diphtheria toxin subunit alpha gene (DTA*G128D), as well as widespread eGFP fluorescence in the absence of Cre recombinase.
