Generation of a conditional mouse model with selective lack of WASp in B lymphocytes (B/WcKO mice). (A) Schematic representation of the targeting strategy. A Was allele with exons 2-6 flanked by loxP sites and a neomycin-resistance (Neo) cassette flanked by frt sites was introduced in embryonic stem cells by homologous recombination (targeting construct). Correct targeting was verified by PCR using appropriate primers. Was locus-targeted mice were bred to transgenic mice expressing the FLP1-recombinase under the Rosa 26Sor promoter, leading to excision of the Neo cassette and allowing generation of Wasfl/fl mice. (B) Representative flow cytometric analysis of expression of CD19 and WASp in peripheral blood lymphocytes of mice with the indicated genotype.
