Generation of the Ebp1 null mouse. A. Schematic representation of the retroviral integration site within the first intron of the mouse pa2g4 (Ebp1) gene in the ES clone OST 186047 is indicated. Exons are represented as boxes. B. The locations of the PCR primers (LTR2, Ebp1 R, Ebp1 F) used in genotyping are indicated. Their positions (in base pairs) relative to the sites of integration are shown (not drawn to scale). LTR = long terminal repeat; SA and SD = splice acceptor and splice donor sites, respectively; PGK = phosphoglycerate kinase 1. C. A typical genotyping analysis showing the 308 bp PCR fragment for a wild type allele and the 253 bp product that detects the viral integration site. The products were separated by agarose gel electrophoresis and visualized by ethidium bromide staining.