OBJECTIVETo investigate the mRNA expression profiles of megakaryocytes (MKs) from human cord blood CD34+ cells ex vivo expanded using Solexa technique.

METHODSCD34+ Cells were isolated using density gradient centrifugation and magnetic activated cell sorting. Cultures were stimulated with recombinant human thrombopoietin (100 ng/ml). After 12 days, the MKs fraction was separated from the non-MKs fraction using an anti-CD41 monoclonal antibody by immunomagnetic sorting. The mRNA expression of MKs and non-MKs was detected by Solexa sequencing.

RESULTSWe obtained 3 773 147 and 3 533 805 Tags from MKs and non-MKs, respectively. The amounts of unambiguous tags were 3 291 132 and 2 967 947 and those of distinct tags were 197 769 and 245 318. The expression of 1161 genes was up-regulated and that of 902 genes down-regulated. The expression of 2717 tags was up-regulated and that of 1519 tags down-regulated.

CONCLUSIONSMKs and non-MKs have remarkably different mRNA expression profiles. The differential gene-encoded products may be involved in cellular development, adhesion, apoptosis metabolism, intra- and intercellular signal transduction, and immune response. Further studies on this topic may clarify the expression mechanism, signal transduction, and regulation mechanisms.