Figure 1.

Targeting strategy for MeCP2-e1-specific germline ablation. Site directed mutagenesis was used to alter the exon 1 translational start site ATG to TTG in the Mecp2 locus excised from a genomic BAC clone. A neomycin resistance gene (NEO) flanked by flippase recognition target sites (FRT) was inserted into exon 1 to produce the targeting vector (top) which was then electroporated in C57BL/6N ES cells for homologous recombination. ES cells incorporating the targeting vector were selected for neomycin resistance then the NEO cassette was excised by expressing flippase, producing the mutant allele (middle). PCR primers detecting the mutant and WT Mecp2 alleles are shown as colored arrows. Genotyping PCR was performed from DNA obtained from tail snips.