Genetic and functional characterization of miR 490. (A) Endogenous miR 490 expression patterns were monitored by quantitative RT-PCR using CD34⁺ cells differentiated in vitro over 21 days using a bilineage culture system; miR 150 expression is shown for comparison. (B-E) CD34⁺ cells transduced with lentiviruses LV 000 or LV490 were puromycin-selected (or not for mock-treated controls) and used for monitoring miR 490 expression patterns over a 21-day period (B); expression values for normal (NO) and ET platelets are shown for comparison. Hematopoietic progenitor assays were completed at day 14 after lentivirus infection (C), megakaryocyte colony assays on day 10 after infection (D), and megakaryocyte/erythroid lineage specification was analyzed at day 7 after infection by flow cytometry using anti-CD41 (Mk marker) or anti-glycophorin A (erythroid) antibodies for quantification (displayed in boxes; E). All results are from a single representative experiment repeated on one occasion. (A-B) P values were calculated by paired t test comparing aggregate miR 490 3p and miR 490 5p time series data.