Fig. 1

Evolution of enhancer-blocking insulator proteins (IBP) in arthropods. Gains of IBPs are indicated by blue stars, potential losses by red crosses. Blue circles in the table indicate the presence of transcripts of a given IBP in transcriptomes. Multiple blue circles indicate the number of copies found. Transparent circles indicate the putative absence of transcripts of an IBP. The backbone tree topology is adopted from [38]. The phylogenetic relationships among outgroup taxa (i.e., Onychophora, Tardigrada, and Nematoda) are according to [62]