Fig. 1.

Conditional inactivation of PLK1 in human cells through gene targeting and Cre-mediated recombination. (a) Diagram of the PLK1 locus and adeno-associated virus vectors used to create floxed (PLK1^flox) and null (PLK1^Δ) alleles. loxP sites (triangles) and FRT sites (circles) are shown. (b) Southern blot analysis confirming gene replacements and Cre-induced recombination in PLK1^flox/Δ cells. (c) Extracts from PLK1^flox/Δ cells infected with Adβgal or AdCre were blotted with antibodies against the C terminus (Upper) or N terminus (Lower) of Plk1. The asterisk denotes a cross-reacting band used to confirm equal loading. (d) Cells infected as in c were scored for the fraction of interphase, mitotic, and micronucleated cells by Hoechst staining and fluorescence microscopy. Error bars denote SEM.