Fig. 1.

Scheme of vertebrate phylogenetic tree showing well-characterized transposable elements (TE)-exaptation events into enhancers and insulators. Different TE exaptation events are indicated with different colors. Circles indicate the branch where the corresponding TE subfamily originated and/or diversified before exaptation, whereas filled circles indicate the branch where a particular TE instance was exaptated as a regulatory element. References for TE origins are LF-SINE, Bejerano et al. (2006); AmnSINE, Sasaki et al. (2008); MIR/CORE-SINE, Gilbert and Labuda (1999, 2000); mammalian apparent LTR (MaLR), Smit (1993); ERV9, Costas and Naveira (2000); and B2 SINE, Churakov et al. (2010). Other references can be found in table 1. Branches not drawn to scale.