mRNA regulation during erythroid differentiation. (A) FACS plot depicting progressive stages of in vivo fetal liver erythroid differentiation used for RNA-seq; stages R1 through R5 reflect progressively further differentiated erythroid precursors, as they gain TER119 and then gain and lose CD71. The RNA-seq expression patterns of highly induced and repressed genes (rows) at differentiation stages R2 to R5 (columns) are displayed as a heat map. Expression of R3, R4, and R5 is shown as a ratio compared with R2; red represents an increase in expression; and green, a decrease in expression for each gene. The GO for highly induced and repressed genes is shown for terms with false discovery rate < 0.05. The RNA-seq data for each developmental stage were pooled from at least 2 independent experiments. (B) Expression levels of the indicated transcripts were determined by RNA-seq analysis of R2 to R5 cells isolated from D14.5 fetal liver cells. Results are expressed as ratios relative to the normalized read number in the R2 stage. Correlation against quantitative PCR for each transcript was also performed, and the coefficient of determination is shown on the right.