Fig 1.

A-C. Control injections of gfp double stranded RNA (gfp dsRNA) did not change the circadian period(τ) of rhythmic running wheel activity in Madeira cockroaches (n = 10 of 13). (A) Double-plotted running wheel activity of a Madeira cockroach in constant darkness revealed only small, random changes in its period during the course of the 42 days long recording. An example plot (total n = 13) is shown. At day 7 (star) gfp dsRNA was injected, the animal was sacrificed at day 42 (cross). Chi-square periodogram analysis of the number of running wheel turns indicated significant rhythmicity with a period of 24.07 h 1–7 days before gfp dsRNA injection (B) and 23.35 h 2–4 weeks after the injection (C).