Lmx1b^{tm3(cre/ERT2)Rjo}

A C->A transition (changing the asparagine N, at position 246 to lysine, K) was introduced into exon 5 to produce a null allele of Lmx1b. Subsequently, an IREScreERT2 cassette, followed by a loxP-flanked PGK-neo, was inserted into the 3'UTR of the locus by homologous recombination in PC3 ES cells. Cre mediated recombination then removed the PGK-neo cassette upon transmission from male chimeric mice. The protamine-cre transgene contributed by the PC3 cells was separated from the knock-in allele by crossing germline male mutants with C57BL/6 mice. (J:149241)