Fig. 1: Fibropapillomatosis tumors and differential transcript expression.

a (Top, left) Fibropapillomatosis-afflicted green sea turtles (Chelonia mydas) in one of the hospital’s seawater tanks, awaiting tumor removal surgery. Established tumors are visible as large pinkish outgrowths. Top, middle: Numerous new growth tumors occurring around the ventral tail and rear flipper area of patient 25-2018-Cm ‘Lilac’. Top, right: Postsurgical regrowth tumor imaged after surgical resection. Regrowing tumor is the pinkish tissue, and is surrounded by paler non-tumored skin. Bottom: A computed tomography (CT) scan of fibropapillomatosis-afflicted C. mydas. CT is one of the approaches used for diagnosing internal tumors. A large kidney tumor is circled. In all other images, arrows indicate selected examples of external tumors. b, c Overlap of transcripts significantly differentially expressed (DE) (as called by DESeq2) in fibropapillomatosis from the RNA-seq data. Transcripts were considered significant if passing the following cutoffs: adjusted P value of <0.05 and log₂ fold change of >2 or ≤2. b Overlap of DEs from the following comparisons: established external FP, new growth external FP, and regrowth external FP, when all are compared to healthy skin for differential expression analysis. c Overlap of DEs from the following comparisons: established external FP, kidney FP, and lung FP, each compared to their non-tumored tissue sources for differential expression analysis (healthy skin, healthy kidney, and healthy lung, respectively). d Principle component analysis (PCA) of all internal tumor samples compared to external tumor samples, RNA-seq. e PCA of all samples, includes all tumor and nontumor samples, RNA-seq. In the figure key external is abbreviated as ‘Ext.’.