Waves of Retrotransposon Expansion Remodel Genome Organization and CTCF Binding in Multiple Mammalian Lineages Dominic Schmidt,1,2,6 Petra C. Schwalie,3,6 Michael D. Wilson,1,2 Benoit Ballester,3 Aˆ ngela Gonc¸alves,3 Claudia Kutter,1,2 Gordon D. Brown,1,2 Aileen Marshall,1,5 Paul Flicek,3,4,* and Duncan T. Odom1,2,4,* 1Cancer Research UK, Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK 2Department of Oncology, Hutchison/MRC Research Centre, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK 3European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK 4Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK 5Cambridge Hepatobiliary Service, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 2QQ, UK 6These authors contributed equally to this work *Correspondence: fl
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[email protected] (D.T.O.) DOI 10.1016/j.cell.2011.11.058 SUMMARY from fly to human (Burcin et al., 1997; Klenova et al., 1993; Moon et al., 2005). Originally identified as a transcriptional regu- CTCF-binding locations represent regulatory se- lator for the c-myc oncogene (Baniahmad et al., 1990; Filippova quences that are highly constrained over the course et al., 1996; Lobanenkov et al., 1990), CTCF remains the only of evolution. To gain insight into how these DNA identified sequence-specific DNA-binding protein that helps elements are conserved and spread through the establish vertebrate insulators (Bell et al., 1999). Additionally, genome, we defined the full spectrum of CTCF- CTCF has been implicated in transcriptional activation, repres- binding sites, including a 33/34-mer motif, and iden- sion, silencing, and imprinting of genes (Awad et al., 1999; Burcin et al., 1997; Filippova et al., 1996; Klenova et al., 1993; Lobanen- tified over five thousand highly conserved, robust, kov et al., 1990).