Figure 1.

Generation of E2f3a and E2f3b knockout mice. a. Partial exon/intron structure of the mouse E2f3 gene. The schematic illustrates the E2f3 locus with two separate promoters driving the expression of E2f3a and E2f3b. The two transcription start sites are indicated by bent arrows. The targeting vectors and the final E2f3a and E2f3b targeted alleles are shown on the left and right, respectively. The solid bar represents a HindIII-BamHI fragment used as the Southern probe. The LoxP sites are indicated as solid triangles; PCR primers are indicated by arrows. b. Southern blot (top panels) and PCR genotyping assays (bottom panels) were performed on MEFs with the indicated genotypes. c. Western blot analysis using E2F3-specific antibodies was performed on lysates derived from MEFs with the indicated genotypes. d. Micrograph of one month-old mice with the indicated genotypes. e. Genotypic analysis of offspring derived from E2f3^+/−, E2f3a^+/− and E2f3b^+/− intercrosses (5^th generation FVB). Fisher exact probability test was performed on each genetic group in comparison to the wild type group; highly significant results are indicated by an (^a). f. Body weights of E2f3^+/+ (grey), E2f3a^−/− (red) and E2f3b^−/− (blue) mice at the indicated ages; n, number of animals measured for each genotype at each age. * indicates the significant p-value. Student t-test was performed on each genetic group in comparison to the wild type group.