Fig. 7.

Day-night variation in relative expression levels of PDE6 genes in zebrafish. Double plots of mean relative expression over 24 h for rod- (a) and cone-specific (b) PDE6 genes. a The levels of pde6a and pde6b do not vary, while for pde6ga there is a drastic difference between day and night, being its highest expression levels in the early morning (8:00), after a constant expression increase during the night. Small variation was observed for pde6gb levels, being its highest levels at early night (00:00). b The expression levels of pde6c do not vary, while there is a ~20 fold variation for pde6hb between day and night, being its expression peak in the early morning (8:00) with a gradual reduction during the day. The variation for pde6ha is more drastic; there is a peak of expression in the middle of the day (17:00) and a subsequent ~120 fold reduction until the middle of the night (4:00). Expression levels for each gene are relative to the mean of zebrafish actb1 and tuba1b (2^-ΔCq) and error bars represent standard deviations. Shaded areas represent the dark period of a 24-h cycle. Note that both graphs are at different scales in order to be able to visualise the high expression levels of pde6ha during the day