Comparison of gene expression profiles of p45-/- primary megakaryocytes and WT primary megakaryocytes

Whole livers were collected from mouse fetuses at embryonic day 13.5 (E13.5), and single-cell suspensions were prepared by successive passage through 25-gauge needles. Fetal liver cells were maintained in RPMI1640 (Wako, Osaka, Japan) supplemented with 20% charcoal-stripped fetal bovine serum (FBS), 100 U/ml penicillin, 100µg/ml streptomycin, and 50ng/ml recombinant human thrombopoietin (TPO) (generously provided by Kyowa Hakko Kirin Co. Ltd.). Megakaryocytes were harvested for RNA purification from a day-3 culture. CD41+ cells were enriched using biotinylated anti-CD41 antibody (Serotec; clone MWReg30) and streptavidin-coupled Dynabeads (Dynal Biotech ASA) from a culture of E13.5 fetal liver cells of WT and p45–/– mice. Total RNA was purified from the sorted CD41+ cells. Gene expression was measured in primary megakaryocytes cultured from p45-/- fetal livers and wild type fetal livers at E13.5. Three independent experiments were performed.