plp ⁻ mutant cells contain supernumerary centrosomes. (A and B) WT and plp⁻ larvae were grown from first to third instar at 25°C (A) or 18°C (B). plp⁻ NBs contain supernumerary centrosomes (arrows). The adjacent boxes (grayscale) are magnifications of the indicated proteins showing the apical (top) and basal (bottom) centrioles. Cnn, Centrosomin. (C) Quantification of supernumerary centrosomes was determined by counting the number of NBs containing more than two Asl-positive centrosomes divided by the total number of NBs. Frequency is indicated on each column, and means ± SD percentages were as follows: 25°C (WT: n = 0/57, 7 brains, 0%; plp⁻: n = 15/323, 24 brains, 4.6 ± 0.9%), 18°C (WT: n = 1/148, 9 brains, 0.7 ± 0.2%; plp⁻: n = 30/187, 9 brains, 16 ± 1.3%), and 15°C (WT: n = 6/109, 8 brains, 4.6 ± 0.6%; plp⁻: n = 36/102, 5 brains, 35 ± 1.4%). (D) Mitotic spindles from one WT and three plp⁻ cold-treated NBs; green (MTs), red (Asl), and blue (pH3). Arrowheads label spindle poles. Dashed circles, NBs. Bars: (main images) 5 µm; (insets) 1.5 µm.