Fig. 2. The skin of mitf^−/− adult frogs turns colorless and opaque.

a The representative photographs of adult wild type (WT), tyr^−/−, and mitf^−/− Xenopus tropicalis were displayed to showcase their dorsal view (DV) and ventral view (VV). The photographs were obtained from a sample of 15 adult frogs of each genotype, all of which were 1 year old. b Skin samples approximately 2 mm×5 mm in size were obtained from both dorsal skin (DS) and ventral skin (VS) of wild-type and mitf^−/− Xenopus tropicalis aged 2 years or 1.5 months postmetamorphosis. These samples were utilized in transillumination experiments to assess their translucency properties. Specifically, the experiment involved positioning each sample on a sheet of paper with the word “理想“ and photographing them under consistent lighting and camera settings to assess the visibility of the word. Three frogs were used for each genotype, and one sample of DS and VS skin was collected per frog. Representative photographs of each genotype were presented to illustrate the experimental findings. c Skin samples were obtained with blood or after exlusion of blood from dorsal regions of the same mitf^−/− Xenopus tropicalis aged 8 months. Three frogs were used for this experiment. The representative photograph was presented. The black scale bar in a is 1 cm. The red scale bar in b and c is 1 mm.