Figure 3. Generation of Iqcg knockout mice.

(A) Schematic of the “knockout first” targeting strategy used for generating Iqcg KO mice. This strategy introduced an Flp-recombinase target (FRT)-flanked selection cassette into the intron after the fifth exon of Iqcg, which could trap the transcript through the Engrailed-2 splice acceptor (En2 sA) element and truncate it through the SV40 polyadenylation signal (pA). LacZ encoding β-galactosidase was a reporter gene that could be used to trace the expression pattern of the Iqcg. Neomycin resistance gene (Neo) was used as a marker for ES clone screening which was driven by an autonomous promoter (hBactP). IRES: internal ribosome entry site. (B) A representative genotyping by PCR assay using primers specific for mouse Iqcg (5′arm and 3′arm) and LAR3 (designed on the En2 SA element of the targeted allele). HE: heterozygote. (C) KO efficiency examined by Western blot analysis in representative tissues.