Figure 1.

After light entrainment, dissipation of locomotor rhythms in pdf⁰¹ mutants is gradual. Young female flies were entrained for 6 d in 12 hr LD cycles and then released into DD for 9 d. The representative data are double plotted, with the last 24 hr repeated on the next row. Rhythmic (R) and arrhythmic (AR) designations refer to behavioral analysis results from periodogram analysis for DD days 1-9. Most control flies (y w;;) remain rhythmic in DD. pdf⁰¹ flies (y w;; pdf⁰¹) often retain residual rhythms for 2-3 d of DD before becoming arrhythmic. Approximately 30% of pdf⁰¹ flies retain weak, fast-running rhythms in DD (example in the rightmost plot).