Fig. 1. Wing discs from sevelen (wild-type) larvae or Cdk1^ts larvae. Eggs were collected and aged to the late second instar larval stage at 18°C. Larvae were then shifted to 30°C for 2 days, after which they were fixed. Discs were dissected and stained for DNA with the dye, bis-benzidine (Hoechst). Wing discs in which Cdk1 has been inactivated are, typically, smaller in size compared with similarly treated sevelen discs and have fewer cells that are bigger than normal. Bar, 25 µm.