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Fig. 3. Targeted disruption of the Disp gene. (A) Schematic diagram
showing the Disp genomic locus, the targeting vector and the mutant
allele. The top line shows a partial restriction map of the Disp
genomic locus. The Disp genomic locus consists of eight exons
(E1-E8). The second exon (E2) contains the translation start ATG and is
followed by a
50 kb intron. A large Disp genomic locus suggests
that Disp may be subject to intricate transcriptional regulation. The
regions between the broken lines represent the 5' and 3' regions
of homology and X indicates events of homologous recombination. The location
of the fragments used as the 5' or 3' external probes in Southern
blotting are shown, as well as the sizes of the fragments detected for
wild-type and targeted alleles. (B) Southern blot analysis of targeted
Disp
E8 allele. Southern blot analysis of genomic DNA from 9.5
dpc embryos generated from matings between Disp
E8+/- heterozygous animals. DNA was digested with
EcoRI and hybridized with the 3' probe. The resulting 4.5 kb
and 5.2 kb bands correspond to the wild-type and targeted allele,
respectively.