Fig 1.
Mean waveforms of locomotor activity under different lighting conditions from 2 to 7 dpf.
Larvae reared under different light conditions (A: LDW, n = 35, B: LDB, n = 30, C: LDR, n = 30, D: DD, n = 45). Vertical axis represents activity (m/10 min) and horizontal axis zeitgeber/circadian time (ZT/CT). Bars above each panel indicate the lighting conditions [black bars indicate darkness, white bars indicate white light (LDW), blue bars indicate blue light (LDB), and red bars indicate red light (LDR)] and the day post-fertilization (dpf). Data are expressed as mean ± SEM.
Fig 2.
A circular representation of the phases of zebrafish activity across the 24 hours from 5 to 7 dpf under LDW, LDB and LDR.
The dots represent the acrophase of each zebrafish larvae. The arrows indicate the average phases represented as vector and in each circle the mean vector length (r) and the mean acrophases (a) in ZT are reported. The circle inside each panel represents critical values of the Rayleigh test (p<0.05) and the coloured part show the duration of light phase (ZT 0–12). The dotted lines represent the confidence intervals.
Fig 3.
Daily activity under different lighting conditions from 2 to 7 dpf.
Data are expressed as mean ± SEM. Letters indicate statistical differences between the different days for each lighting condition (one-way ANOVA; Tukey’s post-hoc test, p<0.05). Symbols indicate statistical differences between the lighting conditions (two-way ANOVA; Tukey’s post-hoc test, p<0.05).
Fig 4.
Daily expression levels of clock1, bmal1, per1b, per2 and dbp at 0, 3, 7 dpf in zebrafish larvae.
Larvae reared under different light conditions (LDW, LDB, LDR, DD) were sampled every 6 hours at 0 (A, D, G, L, O), 3 (B, E, H, M, P) and 7 (C, F, I, N, Q) dpf. Data are expressed in % (100% is the maximum level detected for each gene in all dpf) and each value represents mean ± SEM (n = 4). The bars above each group indicate the daily LD cycle. White bars represent the light phase and black bars represent phases of darkness. The DD group was kept under constant darkness. Asterisks indicate significant rhythms identified by Cosinor analysis (p<0.05).
Table 1.
Mesor, Amplitude and Acrophase defining clock gene expression rhythms at 0, 3 and 7 dpf.
Fig 5.
Daily expression levels at 0, 3, 7 dpf of clock1 bmal1, per1b, per2 and dbp under different lighting conditions.
The data are expressed as mean ± SEM. The letters above each bar indicate significant differences for each condition among the days (one-way-ANOVA, p<0.05). The symbols on the top indicates statistically differences between the lighting conditions (two-way-ANOVA, Tukey’s post-hoc test, p<0.05).