Figure 4.

β-gal targeted to megakaryocyte progeny of −889nLacZ-transduced human CD34+ cells. CD34+ cells were transduced with a MuLV-derived construct, −889nLacZ, encoding β-gal and then induced to form megakaryocytes in culture. Histochemical staining was performed after 10 days of differentiation to determine the percentage of the total cell population expressing β-gal. (a–c) β-Gal activity was detected in 0% of untransduced cells (a), 8% of cells transduced with −889nLacZ (b), and 19% of cells transduced with CMVnLacZ (c). (d–f) The −889nLacZ-transduced CD34+ cells were simultaneously stained for β-gal activity and αIIbβ3 expression to determine whether β-gal expression was selectively targeted to progeny megakaryocytes. Arrows point to the same two cells unstained (d), stained for β-gal activity (e), and stained for αIIbβ3 (f).