B6;129S-Rorb^{tm1.1(cre)Hze}/J

Rorb^{tm1.1(cre)Hze}

targeted mutation 1.1

Recombinase-expressing

Rorb

RAR-related orphan receptor beta

19

Cre, Cre recombinase, bacteriophage P1

5507855

Cre expression is strong in the zonal layer of the superior colliculus and subregions of thalamus. Dense, patchy Cre expression is seen in cortical layer 4, with sparse Cre expression in cortical layer 5 and 6. Cre recombinase is also expressed in trigeminal nucleus and small patches of cells in cerebellum.

(129S6/SvEvTac x C57BL/6NCrl)F1

The targeting vector contained, from 5' to 3', a partial Rorb sequence from intron 9 (with an frt3), a partial Rorb exon 10 sequence including the endogenous stop codon, an internal ribosome entry site 2 (IRES2) sequence, a Cre recombinase gene, a bovine growth hormone polyA sequence, an AttB site, a PGK promoter-Neomycin resistance gene-PGK polyA cassette, an frt5 site, an mRNA splice acceptor, the 3' portion of the hygromycin gene with SV40 late polyA signal, and an AttP site. This construct was electroporated into G4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. Chimeric mice were bred to PhiC31-expressing mice to remove the AttB/AttP-flanked sequences (PGK-Neo-polyA::frt5::RNA splice acceptor::3'hygro-polyA) and replace it with the recombined AttB/AttP site (AttL). The resulting Rorb-IRES2-Cre-D mice were bred with C57BL/6J wildtype mice to remove PhiC31 transgene.

C57BL/6J

When maintaining a live colony, heterozygous mice may be bred to wildtype siblings or to C57BL/6J inbred mice. The donating investigator reports homozygous mice are viable but demonstrate an abnormal walking gait with an exaggerated high step. Breeding homozygous mice together produces some pups with more severe phenotype (runty and tremulous).