Figure 2. The Plt8 Mutation Disrupts Production of the Suz12 mRNA and Protein.

(A) A schematic representation of part of the Suz12 locus is shown to detail the intron and exon structure (at left). Primers were designed to flank the site of the mutation (red arrow), and RT-PCR was performed on cDNA prepared from bone marrow. An aberrantly spliced product (asterisk) was identified in cDNA prepared from Suz12^Plt8/+ mice that was not present in wild type.

(B) Protein lysates were prepared from sex-matched embryonic day 12.5 (E12.5) embryos for analysis by Western blotting, which revealed that Suz12 and Ezh2 protein levels were reduced in Suz12^Plt8/+ embryos. Suz12 protein levels appeared equivalent in Suz12^Plt8/+ embryos and embryos heterozygous for the genetrap allele (Suz12^502gt/+). Equivalent amounts of protein were run in each lane (20 μg), and histone H3 was used to verify equal loading. Western blot signal intensity was quantified using a densitometer; results represent the average of two independent experiments expressed as protein expression in Suz12^Plt8/+ (gray) and Suz12^502gt/+ (black) embryos relative to wild type (white, 100%).