Recruitment efficiency of centriole duplication factors scales to ploidy level. (A, C, and E) Immunostaining of Cep152 (A), Plk4 (C), and SAS-6 (E) in synchronized cells with different ploidies. The centrioles were marked by immunostaining of centrin (A) or CP110 (C and E). (B, D, and F) Percentages of Cep152-, Plk4-, and SAS-6–positive mother centrioles in A, C, or E. Values represent means ± SE of three independent experiments (asterisks indicate significant differences from diploid cells; *, P < 0.05; ** P < 0.01, t test). At least 114 (B), 147 (D), or 250 mother centrioles (F) were analyzed for each data point. (G) Immunostaining of centrin in HAP1 cells with different ploidies transiently expressing GFP or GFP-Plk4. Broken lines mark cell boundaries. Insets show 2× (A, C, and G) or 3× (E) enlarged images of the centrioles. (H) Quantification of daughter centrioles generated by each mother centriole in G. At least 88 mother centrioles from two (vector control) or three (others) independent experiments were analyzed for each condition. The numbers of supernumerary centrioles were significantly different between haploid and diploid or diploid and tetraploid GFP-Plk4–expressing cells (P < 10−7 or P < 0.01, t test, respectively).
