Rhythmicity parameters.

Percentage of control (wt) or DmIh mutant (Ih−) flies that are rhythmic (%R), weakly rhythmic (%WR), or arrhythmic (%A) in LD or DD conditions. Period (mean±SD) was calculated by chi-square periodogram using rhythmic and weakly rhythmic flies. Statistics refer to difference between control and mutant genotype regarding the percentage of R, WR, and A flies (χ2 test), or the period length (Mann-Withney test).