Fig. 3. Caspase 3 and caspase 6 activities. Caspase 3 (A,C) and caspase 6 (B,D) activities were measured in the presence (+) or absence (-) of a specific inhibitor (A,B) in lens extracts from wild-type and DKO mice from three age groups. The activities plotted in C and D as a function of animal age represents the difference in caspase activity measurements in the presence or absence of a specific inhibitor. Specific activities are in nmol of pNA/hr/ng of total extract protein for caspase 3 or in nmol of AMC/hr/mg of total extract protein for caspase 6. The error bars represent data error analyzed using linear models in R (Ver. 2.1.1). ^*P<0.001; ^**P=0.007; ^***P=0.003.