FIG. 1.

Targeting of Rps19 in ES cells. (A) Structures of the wild-type Rps19 gene, the Rps19 targeting construct, and the resulting targeted Rps19 gene. Black boxes represent protein-coding exons, and the grey box is the 5′ UTR. A linearized construct was used with a phosphoglycerate kinase promoter-driven diphtheria toxin (PGK-dt) gene followed by a SL1180 cloning vector. A thymidine kinase promoter-driven neomycin resistance gene (Tk-neo) was used to replace the 5′ UTR and exons 1 to 4 of Rps19 by homologous recombination together with the 2.8- and 4.5-kb murine wild-type sequences surrounding the Tk-neo cassette. (B) BstZ17I-digested genomic DNA from an Rps19^+/− mouse and an Rps19^+/+ mouse was analyzed by Southern hybridization using the 5′ probe. The larger fragment (arrow) of 10.1 kb was produced in the absence of the BstZ17I site in intron 5 of the targeted allele.