Behavioral rhythms of locomotor activity are disrupted in bsx mutant zebrafish larvae. (A) Locomotor activity of WT (blue, n = 20), bsx+/− (green, n = 38) and bsx−/− (red, n = 20) zebrafish larvae monitored under a constant dim light schedule (DimDim) from 6 to 8 dpf, after entrainment by three 1 L:12D cycles and two light-dim light cycles. The average distance moved (cm/10 min) is plotted on the y-axis and circadian time (CT) is plotted on the x-axis; error bars indicate SEM. The experimental design of the photic treatment before and throughout activity monitoring is shown at the top. White boxes represent light, black boxes represent dark, and gray boxes represent dim light. (B) Bar graphs displaying average periods of the three genotypes. No significant differences were detected by ANOVA (p > .05). (C) Circular plots of the average circadian phase of the rhythms of the three genotypes. Arrow directions represent the average phase for each genotype and arrow length represents the variance (longer arrow stands for low variance and vice versa); dots represent the values of individual larvae (note the high variance in bsx−/− mutant larvae). (D) Bar graphs displaying the mean amplitudes of the relative rhythms for the three genotypes, showing significant effect of the genotype (p = .0013, ANOVA); mutant (bsx−/−) larvae display a decreased amplitude compared to wildtype (bsx+/+) larvae (p < .001, Tukey's multiple comparisons tests). ***p < .001; ns, not significant
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