Fig. 3. cyd-1 and cdk-4 cell division defects precede growth defects. Size of cyd-1(he112) and cdk-4(gv3) homozygous mutants and wild-type siblings (genotypes: cyd-1(he112)/mnC1 and cdk-4/+ or +/+) is plotted as a function of time of postembryonic development at 15°C. The growth retardation of cyd-1 and cdk-4 mutants becomes first apparent in the L2 stage, subsequent to failure of some late embryonic and all postembryonic L1 divisions. Points indicate mean of five measured animals±s.d.