Ext1^tm1.2Vcs

An inverted loxP site was introduced upstream to exon 2 in a genomic fragment containing the Ext1 gene. The fragment was then subcloned into a vector upstream of the forward-facing loxP-flanked neomycin resistance (Neo) cassette. The linearized targeting vector was electroporated into R1 ES cells. Homozygous Ext1tm1Kjns mice were crossed to Prxx1-cre transgenic mice that express cre in the germline. This results in two consequences, either excision of neo only (tm1.1) or neo-excision and exon 2 inversion (tm1.2). Homozygous exon2-inverted animals display embryonic lethality. (J:157599)