FIG. 1.

Generation and analyses of targeted alleles for Phd1, Phd2, and Phd3. (A) Gene targeting strategy for Phd2. In targeted Phd2 locus, exon 2 is flanked by two loxP sites. Exon 2 is deleted by Cre-mediated recombination. Ex, exon; hsv-tk, herpes simplex virus thymidine kinase; S, Sca I; H, Hind III; Neo, neomycin cassette; hatched square, Frt site (flanking the Neo cassette); open triangle, loxP site; arrows 1, 2 and 3, PCR primers for genotyping. (B to D) Southern blots for Phd1, Phd2, and Phd3 loci demonstrating the deletion of floxed exons. (E to G) PCR of genomic DNA samples to confirm the deletion of floxed exons. Different relative sizes of the mutant and wild-type bands are due to the presence or absence of the neomycin cassette. (H to J) RT-PCR analyses to confirm the lack of wild-type mRNA transcripts in Phd1^−/−, Phd2^−/−, and Phd3^−/− RNA samples.