RNA-Seq analysis of transcript levels in primary erythroid progenitor cells and erythroblasts. RNA was extracted from E13.5 fetal liver progenitor cells and erythroblasts, and from G1E cells and G1E-ER4 + E2 cells. The RNA was converted to cDNA followed by massively parallel sequencing (RNA-Seq). (A) A correlation plot comparing the levels of expressed exons in biologic replicates of erythroblast RNA showing a high degree of reproducibility. Each dot represents a gene, and the density of genes showing similar expression changes is represented by the heat map, with purple indicating a greater number of exons and yellow indicating a lower number of exons at each point. (B) A correlation plot comparing the levels of expressed genes in primary erythroblasts and progenitor cells showing distinct transcript profiles in the 2 populations. (C) A correlation plot comparing the levels of expressed genes in G1E cells and primary progenitor cells showing significant similarity in the transcript profiles. (D) A correlation plot comparing the levels of expressed genes in G1E-ER4 + E2 cells and primary erythroblasts showing significant similarity in the transcript profiles. (E) Top panel: An analysis of the changes in the level of genes that are dysregulated in primary erythroblasts compared with progenitor cells (green). The genes are organized from most down-regulated at the left to most up-regulated at the right. Bottom panel: An analysis of the same dysregulated genes in G1E-ER4 + E2 cells compared with G1E cells (red). Approximately 85% of the dysregulated genes change their expression levels in the same direction.