Expression levels of

DNMTs in normal hematopoietic cells measured by competitive PCR. (A) Examples of the competitive PCR assay forDNMT3B. Phosphorimages of 2 agarose gels stained with Vistra green are shown. The lanes contained the products amplified from a constant amount of the cDNA mixture, and the competitor DNA prepared in successive 3-fold dilutions. (B) Graphs show the regression analysis of the results obtained in panel A. The initial amount of target DNA was estimated by the point where log(products from competitor/products from target) = 0. (C) Levels of the DNMT transcripts in normal hematopoietic cells. The number of samples are neutrophils, n = 3; monocytes, n = 3; peripheral T cells, n = 3; PHA-activated T cells, n = 3; bone marrow cells, n = 6; CD34⁺ cells, n = 5. The levels of DNMTs are displayed as relative values calculated such that the mean of the normal bone marrow cells would equal a value of 1 after correcting the variations by the levels ofGAPDH.