TCP domain’s β9–10 surface is required for stabilization of developing centrosomes. Control and Sas-4–TCP-3 spermatocyte centrosomes normally elongate and recruit Sas-4, Asl, γ-tubulin, Ana2, Cnn, and D-PLP (A–E), whereas Sas-4–TCP-1 and -2 variants recruit lesser amounts of these proteins and exhibit significantly reduced centrosome lengths (graphs on the right and F). (Scale bar, 0.5 μm.)