Characteristics of circadian rhythms in wild type and mutant hamsters of both sexes.

a, b, c, d: common superscripts within each measure indicate genotypes do not differ significantly (p>0.05, Tukey’s HSD). Variability of activity onsets, offsets, and acrophase refers to the mean of the standard errors of the fit of the regression line used to estimate free running period in individual hamsters of each of the indicated genotypes.