Fig. 1.

Gene targeting and embryo phenotype. (A) A schematic representation of the VE-PTP targeting strategy. An 11.8-kb VE-PTP genomic region along with flanking homology sequence (HBox) was used for bacterial homologous recombination with VelociGene technology (9). A TM-β-gal/PGK-Neo reporter cassette was inserted, deleting from 27 nucleotides (in exon 2) through exon 3 in the targeted allele. (B) Quantitative RT-PCR results of transcript levels of VE-PTP and lacZ with E9.5 embryo RNA from WT (n = 3), VE-PTP^Lz/+ (Het, n = 3), and VE-PTP^Lz/Lz (knockout, n = 4). The relative VE-PTP and LacZ expression levels are graphed on separate scales. (C and D) Freshly dissected E9.5 embryos, showing the growth retardation, large heart, and pericardial edema phenotypes seen in the VE-PTP^Lz/Lz embryo (D) compared with VE-PTP^Lz/+ (C).