This figure shows specific circadian data collected from a zebrafish melanoma model. (a) Transgenic fish were generated, which develop a melanoma in which cells are both GFP-tagged and contain a per3-luciferase reporter gene. The lower panel shows a cross-section through a fish revealing the extend of the GFP-positive tumour. (b) Luminenescent gene expression recordings from both a developing melanoma and neighbouring skin reveal that circadian gene expression rhythms are significantly lower amplitude in the tumour and damp faster than in healthy skin. (c) Two strongly light responsive genes, Per2 and 6-4 photolyase, so no transcriptional light induction or rhythmicity in the developing tumour compared to adjacent, healthy skin. (Taken from Hamilton, Diaz-de-Cerio and Whitmore, 2015) [77].