Quantitative PCR confirmation of transcript fold changes from microarray expression profiling. Transcripts were selected for quantitative PCR based on the availability of an efficient intron-spanning quantitative PCR assay. For each gene, the fold change is given between CFU-E and Pro-E (C-P, green bars), Int-E (C-I, blue bars), and Late-E (C-L, pink bars). Solid bars on the left-hand side of each graph represent microarray data; and hatched bars on the right, quantitative PCR data in triplicate from at least 3 biologic replicates of individual samples, including some additional samples not included in the pools on the Affymetrix arrays. (A) Previously described erythroid genes. (B) Differentially regulated transcripts from DE_Sig. (C) Differentially regulated transcripts identified by matched filter analysis (MFUp). (D) Transcripts that are continuously expressed at a high level throughout maturation (CHE).