Gene expression analysis of hematopoietic transcription factors in 10.5-dpc IACs. (A) Gene expression analysis of WT and Twist1^+/− IACs, as assessed by microarray. Normalized signals of indicated transcription factors are shown. Fold change was calculated by dividing the normalized signal from Twist^+/− IACs by the normalized signal in WT IACs. Among factors analyzed, Myb and Gata2 were downregulated in Twist1^+/− IACs. (B) Validation of microarray data. RNA from sorted c-Kit⁺CD31⁺CD34⁺ cells was extracted from 10.5-dpc AGM tissue of mice of indicated genotypes, and gene expression was assessed by real-time PCR using TaqMan probes. Comparative expression levels were calculated using the 2^−ΔΔCT method. WT IAC sample served as a reference. Data shown are means ± SD of technical triplicate samples.