The transgenic construct has the mouse Cxcl4 (Pf4, platelet factor 4) driving expression of the murine F5 (FV) gene including the entire coding sequence. An IRES-EGFP cassette with a bacterial gene was inserted after the F5 coding sequence. A chimeric intron with optimized splice signals was introduced upstream of the F5 cDNA enhance gene expression. Transgenic F5 expression is restricted to megakaryocyt-containing tissues (to spleen and bone marrow). EGFP expression is not detected. (J:86150)