Fig. 1.—
Features of Ruditapes philippinarum major URs. Main features of the largest URs in M- and F-type mtDNAs. (a) Conserved regions, motifs, repeated units and major secondary structures (both at DNA and RNA level). M, M-type mtDNA; F, F-type mtDNA; orange, motif α; turquoise, novel ORFs; dark green, subunit A; orchid, subunit B; red, subunit C; yellow, motif δ; light green, motif γ; black, motif ε; blue, motif β; G, G-homopolymer; Ra, Rb, Rc, R′, R″, R′′′, M-type-specific repeats; R1-R11, Repeats; V, variable length spacer. (b) Circos diagram of the LURs of M- and F-type mtDNA showing transcription depth (orange gradient) and nucleotidic variability (inter-lineage p-distance, gray gradient) of the largest URs. The ribbons link conserved region and motifs within and between major URs. Note.—M-type above, F-type below. From the outside to the inside: transcription level (orange gradient scale 0–9000), p-distance (gray gradient scale 0–0.58), subunits and motifs with links between M-type and F-type. Orange, Motif α; turquoise, novel ORFs; dark green, subunit A; orchid, subunit B; red, subunit C; yellow, motif δ; light green, motif γ; black, motif ε; blue, motif β.