Figure 3.

Proliferation rate of primary mouse embyo fibroblasts transfected with BRCA1. Fibroblasts derived from rb+/+, rb−/−, or rb+/− were cotransfected with a lacZ expression vector and BRCA1 or vector alone. In 2 days, cells were labeled with BrdUrd and stained for β-gal and BrdUrd. Cells positive for β-gal were scored for proliferation assessed by BrdUrd incorporation. (A) Percentage of proliferating cells in the population of transfected cells. (B) Same as in A with the number of proliferating cells in each cell line transfected with lacZ and vector alone taken as a 100%. ■, transfection with vector alone; ▧, transfection with BRCA1. Standard deviations are presented in A and B. At least 100 β-gal-positive cells were analyzed in three fields for each transfection in two independent experiments.