Figure 1.

Targeting the GATA4–FOG-2 interaction in mice. (A) Structure of the N finger of chicken GATA-1 modeled with DNA. The essential valine is highlighted in red in both the illustration and in the sequence alignment of the murine factors, GATA-1 (V205) and GATA-4 (V217), shown below. Note the high conservation of the residues within the N finger of the two GATA proteins. (B) Partial restriction map of the murine Gata4 wild-type locus (top), the Gata4 knock-in targeting vector (middle), and targeted homologous recombination before excision of the selection cassette (bottom). The targeting construct contains the HSV-tk and neomycin resistance (neo^R) genes under the control of the mouse phosphoglycerate kinase (PGK) promoter. Homologous recombination results in replacement of wild-type Gata4 with genomic DNA harboring a substitution of valine to glycine at position 217 in the N finger of GATA-4, as well as the incorporation of neomycin cassette. Gata4 coding exons are shown as empty boxes, whereas the exon used as a probe used for Southern blot analysis is highlighted by a black box. S, SacI; E, EcoRV; B, BglII; N, NotI. (C) Southern blot analysis of ES cell DNA and mouse tail DNA (left panel) showing the presence of heterozygous mutant animals (ki/+). Analysis of E12.5 embryos resulting from an intercross of Gata4 knock-in heterozygotes (ki/+), demonstrating the presence of all expected genotypes (right panel). The wild-type allele (WT) generated a 3.8-kb band after digestion of genomic DNA with BglII. In contrast, the knock-in mutated allele (Ki) generated a much larger fragment because of the replacement of the intronic BglII site with NotI.