<i>In vitro</i> differentiated cells from <i>CKIδ</i> mutant and <i>CK2α</i> mutant ES cells show a longer period-length of the circadian clock than cells differentiated from wild type ES cells.

<p>After 28-day differentiation, the bioluminescence intensity in each well was monitored. (A, D) Averaged bioluminescence traces after <i>in vitro</i> 28-day differentiated <i>CKIδ</i> (A) or <i>CK2α</i> (D) mutant/revertant ES cells (<i>gray</i>, WT; <i>red</i>, homozygous mutant; <i>blue</i>, revertant). Data detrended by subtracting a 24-h moving average are means (<i>n</i> = 24). (B, C, E, F) Distributions and bar graphs of the period lengths of bioluminescence traces in each well. Error bars are SD. Statistical differences were evaluated using one-way ANOVA followed by Bonferroni post hoc test.