Fig. 1
From: Identification of RAG-like transposons in protostomes suggests their ancient bilaterian origin
Genomic organization and phylogenetic tree of RAG and RAGL transposons. a Genomic organization of the mouse RAG locus and the amphioxus RAGL (ProtoRAG) transposon. The legend for panels (a), (b), and (c) is provided at the bottom of panel (c). b Tree depicting phyla within which RAG loci or RAGL or Transib transposons have been identified. Blue, orange and green shading indicate Deuterostomia, Protostomia and Cnidaria, respectively. Branches lacking evidence for RAG/RAGL sequences were omitted. With the exception of Cnidaria, all phyla with identified RAGL sequences contain at least one complete RAGL transposon with the configuration TSD-TIR5′-RAG1L-RAG2L-TIR3′-TSD. Prior to this study, potentially active RAG1-RAG2 gene pairs and RAGL transposons had been reported only in deuterostomes [9], while outside this phylum, only as a single deteriorated RAG1L-RAG2L locus (in C. gigas) was previously reported [10]. c Genomic organization of the most complete RAGL copies detected in Mollusca, Nemertea, and Cnidaria. Predicted RAG1L/RAG2L coding regions, TIRs, and TSDs are depicted, using symbols explained in the legend at bottom. Supporting transcriptomic data are indicated along with corresponding TSA entry (Additional file 8: File S1 and Additional file 9: S2). Green and gray arrows indicate transcripts corresponding to coding and untranslated regions, respectively. Unmapped regions of transcripts are shown unfilled while the black star in GFRY01002319.1 indicates a frameshift caused by an 8 bp deletion