Creation of conditional ASB2 knockout mice. (A) Schematic representation of (a) the wild-type allele (+) of the mouse ASB2 gene, (b) the structure of the correctly targeted allele with the introduced neomycin resistance cassette and loxP and FRT sites, (c) the conditional floxed allele (fl) produced by Flp-enhanced recombinase-mediated recombination of FRT sites flanking Neo, and (d) the deleted allele (−) produced by Cre recombination of loxP sites surrounding exons 2 to 4. The locations of genotyping primers are also indicated. (B) Schematic representation of the cross-breedings performed to generate Mx1-Cre;ASB2^fl/fl mice as described in the Materials and methods section and inducible Cre-mediated disruption of ASB2 in Mx1-Cre;ASB2^fl/fl mice after poly(I·C) administration. Mx1-Cre;ASB2^+/+ mice that have received poly(I·C) are used as controls (ASB2^+/+). (C) Predicted PCR fragment sizes for wild-type (+), floxed (flox), and knockout (−) alleles of ASB2 using primer sets shown in A. (D) PCR products from mouse tail DNA using primers A, B, and C for the genotyping of ASB2 in 2 Mx1-Cre;ASB2^+/+ and 2 Mx1-Cre;ASB2^fl/fl mice before (-) and 6 weeks after the last poly(I·C) injection.