Figure 4.

Result of transgene stabilization on behavior of primary fibroblast cultures. +, treated with doxycycline; −, not treated. (A) Motility as measured by the number of cells per high-powered field crossing the membrane using a modified Boyden chamber. (B) Cell motion as measured by using time-lapse photomicroscopy. (C) Proliferation as measured by using the percentage of cells incorporating BrdUrd. (D) Cell invasiveness as measured by the number of cells per high-power field crossing Matrigel. In all cases, activation of the transgene resulted in a significant increase.