Top row from the left: DAPI staining of a tadpole larvae of the ascidian, Halocynthia roretzi, see Yamada and Nishida, 376–386. Developing mouse cortex consisting with neural progenitor cells positive for Pax6 (magenta) and neurons marked with Tuj1 (green), see Tsunekawa et al ., 349–357. Histograms of DNA content per nucleus of mouse cardiomyocytes (mono‐ and binucleate cells) during postnatal stages, see Takeuchi, 402–409. Middle row from the left: Switching from proliferation ( PCNA , magenta) to differentiation (Prox1, green) in the lens, see Mochizuki and Masai, 387–401. Anterior view of the lens of 5 dpf zebrafi sh to show lens fi ber convergence (BODIPY ceramide staining) see Mochizuki and Masai, 387–401, Cell division of Rb‐ TKO differentiating cortical neurons, see Ajioka, 324–334. Bottom row from the left: Eye imaginal disc stained by anti‐Elav (pan‐neural marker; green) and Cut (cone cells marker; magenta) see Tsuda and Lim, 358–367. Schematic showing. Cdk5 regulates both presynaptic and postsynaptic proteins and thereby synaptic plasticity, see Kawauchi, 335–348, Developing mouse cerebral cortex. Neural progenitors and multipolar and locomoting neurons, where Cdk5 has various functions, are emphasized, see Kawauchi, 335–347.