Evolutionary history of other ORF1p fusion isoforms. (A) Results of the detection of intact L1 ORF1-derived exons on the host phylogenetic trees. The phylogenetic trees with divergence times were based on the TimeTree (Kumar et al. 2022). Otophysi (a group of bony fishes), Siluriformes (catfishes); Musteloidea (weasels and relatives); Pinnipedia (seals and relatives); Ursoidea (bears and relatives). (MYA) Million years ago. (B) Maximum likelihood-based phylogenetic tree of ORF1p-derived amino acid sequences of fusion proteins and L1 ORF1ps obtained from Dfam database (77 proteins). Each ORF1-derived exon was clustered into a single clade. Ultrafast bootstrap support values (1000 replicates) of internal nodes are shown for the clades of the ORF1-derived exons.
