Generation of <i>Sept7</i> floxed mice and characterization of embryonic lethality of the <i>Sept7</i> knockout.

<p><b>A,</b> Strategy for conditional targeting of <i>Sept7</i>. A neomycin cassette with flanking FRT and lox-P sites was incorporated by homologous recombination in ES cells. The resulting mice were crossed with Flippase expressing mice to remove the neomycin cassette retaining the lox-P flanked (floxed) exon 4. Cre expression leads to excision of exon4 and a downstream frame shift. <b>B,</b> Analysis of embryonic lethality in <i>Sept7</i> knockout mice. Analysis of progeny by genotyping at postnatal day 1 (P1) and embryos at E6.5–7 and E10.5, shows embryonic lethality between E7.5 and E10.5. Significance of the χ² test is given where a difference to Mendelian distribution is indicated by values greater than 5.99 (p = 0.05).