Fig. 1

CircMET RNA identification. a, b Box plots of mean expression (a) and RNA-seq scores (b) of the indicated human MET circRNAs according to circAtlas [58] and circBase [54] dataset collections, respectively. CircMET is highlighted in red. c Mean junction ratio of MET circRNAs identified using circAtlas [58]. Mean junction ratio is defined as the ratio between back-splicing junction reads and the total number of reads aligned to the junction site. CircMET is highlighted in red. d RNA-seq scores of the indicated murine Met circRNAs according to circBase repository [54]. CircMet is highlighted in green. e Schematic representation of MET locus-derived circRNA conservation across vertebrates based on circAtlas [58] conservation analysis output. Filled boxes indicate the presence of the circRNA in each distinct species. Human circMET is reported in red, whereas murine circMET is reported in green. f, g Schematic representation of predicted MET locus-derived circRNA products containing human MET exon 2 (f) or mouse Met exon 3 (g) and related validation by PCR analysis in human gastric cancer (GTL16) and mouse sarcoma (#1640) cells, respectively. Intron–exon circRNA structure and predicted amplicon lengths are graphically represented on the left. Divergent non junction-spanning (non JS) primers were used to detect multiple exon 2- or exon 3-derived circRNAs. PCR bands corresponding to human and murine circMET are highlighted by a red and green box, respectively. h Sanger sequencing of human and murine PCR amplicons in the red and green boxes of panel f and g, respectively. Back-spliced junctions (JS) are highlighted