Fig. 1.

2A-like sequences within non-LTRs. The site of 2A-like sequences and the domain organization within ORF2 of “young” non-LTRs is shown (A). Dendrogram of non-LTR RT domains. The RTclass1 tree file was downloaded from Genetic Information Research Institute and adapted, such that each clade is represented by a single line, lengths representing the most unrelated element within each clade. Clades comprising non-LTRs encoding 2A-like sequences (active or inactive) are shown in bold and branches highlighted, the latest common ancestral node indicated with a closed circle (B).