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. Author manuscript; available in PMC: 2013 Aug 15.
Published in final edited form as: J Immunol. 2013 Jan 15;190(2):737–747. doi: 10.4049/jimmunol.1201278

Fig. 2. Generation of Cd4* mice.

Fig. 2

(A) The strategy. The Cd4 locus contains the Cd4 promoter (P) and silencer (S), the latter located between the first and second exons (while boxes). In the targeting construct, the TRE, together with a neomycin expression cassette (Neo), is inserted immediately upstream of the silencer. The Neo cassette is flanked by FRT sequences (dots) to allow for its Flpe-mediated excision and the subsequent generation of the Cd4* allele. The silencer in the Cd4* allele is floxed (triangles), allowing for Cre-mediated excision and the generation of the Cd4*ΔSallele. The arrows denote primers used for screening ES cells, where primers a/b and c/d amplify the junction sequences of the left and right integration sites, respectively.

(B) PCR analysis of a correctly targeted ES clone. Arrowheads indicate the PCR amplicons produced by primers a/b and c/d depicted in Fig. 2A. The amplicons were verified by sequencing. DNA from parental ES cells (WT) was used as a control. Asterisks, nonspecific amplicons. This ES cell clone was used to produce mice carrying the Cd4* allele.