Expression of megakaryocyte-related genes in V205GR megakaryocytes. Megakaryocytes were isolated from the bone marrow of V205GR and wild-type mice, and the expression of megakaryocyte-related genes and transcription factors was analyzed by semiquantitative RT-PCR. The cDNAproducts were amplified with increasing number of cycles; 31, 34, and 37 cycles for PF4, β1-tubulin, and GATA-2; 34, 37, and 40 cycles for PBP, TXS, c-mpl, GPIX, p45, MafK, FOG-1, and HPRT.