Lmx1b^{tm2(cre/ERT2)Rjo}

An IREScreERT2 cassette followed by a loxP flanked PGK-neo cassette was inserted into the 3'UTR of the Lmx1b locus by homologous recombination in PC3 ES cells. Cre mediated recombination subsequently 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)