Fig. 2. Centriole length is misregulated upon inactivation of Cdk1. In all cases, the mother centriole is on the left and the daughter on the right. Furthermore, we have oriented images so that mothers in longitudinal section have their long axes running top-bottom and daughters in longitudinal section have their long axes facing left-right. Since the section is thinner than the centriole, a longitudinal section through a centriole appears as a pair of parallel lines (representing the walls of the centriole). A centriole in cross-section appears as a circle (Vidwans et al., 1999). The pairs of pictures in A, D and E are adjacent sections from a series. (A,B) Control centrioles from sevelen wing discs incubated at 30°C for 2 days. (C,D,E) Centrioles from Cdk1-inactivated wing disc cells. (A) Both the mother and the daughter in this centriole pair are in longitudinal section. Note that the daughter is shorter than its mother (compare the mother in the left section to daughter in the right). (B) Both the mother and the daughter centrioles are in longitudinal section, with the daughter shorter than its mother. (C) A longitudinal mother-daughter centriole pair with a long mother. Compare the length of this mother to those in A and B. (D) A mother in cross-section with a long daughter in longitudinal section. Compare the length of this mother to that in A and B. (E) A longitudinal centriole pair with long mother and daughter. The daughter is longer than its mother. Bar, 100 nm.