Additional file 6. Failure of in vivo XCI in Setdb1gt/gt female embryos. a. Genomic location (mm10) of the integration site of the gene trap construct. Arrow heads and long arrow indicate the location of oligonucleotides used to identify the integration b. Domain structure of wild type Setdb1 protein and the predicted gene trap β-geo fusion protein. c. Setdb1 protein expression in wild type and gene trap heterozygote MEFs, as determined by Western blotting (at left), quantified compared to the Actin control (at right). Western blots for H3K9me2, H3K9me3 and H3K27me3 are also shown for the same samples, quantified against tubulin. Bar graphs show quantitation of blots with statistics determined by Student’s one-tailed t-test, *** p