Identification of AI467606 as a novel transcriptional target of RUNX1 and its expression pattern at the onset of hematopoietic development. (A) Semiquantitative reverse-transcription PCR analysis of expression of Runx1 and AI467606 during the course of 4 days of Runx1^+/− and Runx1^−/− blast development. (B) Semiquantitative reverse-transcription PCR analysis of expression of Runx1 and AI467606 after Runx1 induction in Runx1^−/− ES cell. (C) ChIP analysis of day 2 blast colony cells. The precipitated chromatin was analyzed using primers specific for AI467606 promoter. All values are relative to the IgG value. (D-E) FACS analysis of AI467606-GFP, CD41, and Tie2 coexpression in blast colonies from day 1 to day 4. Numbers indicate percentages of respective populations. (F) Number of hematopoietic colonies generated by CD41⁺GFP⁻ (white boxes) and CD41⁺GFP⁺ (gray boxes) cell populations. Definitive colony counts include macrophages, macrophages/erythrocytes, granulocytes-macrophages, and mix granulocyte-macrophage-erythroid colonies. EryP indicates primitive erythrocytes. Mean numbers of colonies from 3 dishes of a representative experiment are shown. Error bars represent SEM (n = 3).