Essential role of Cp190 in physical and regulatory boundary formation
Authors: Anjali Kaushal 1; Julien Dorier 1; Bihan Wang 1; Giriram Mohana 1; Pascal Cousin 1; Nicolas Guex 1; Erez Lieberman Aiden 2; Maria Crisitna Gambetta 1
Affiliations: 1) University of Lausanne, Lausanne, Switzerland; 2) Baylor College of Medicine, Houston, Texas
Keywords: f. insulators/boundary elements; h. translational regulation
Animal genomes fold into contact domains defined by enhanced internal contact frequencies with debated functions in establishing independent gene regulatory domains. A large fraction of mammalian contact domain boundaries form by stalling of chromosomal loop-extruding cohesin by CTCF, but most Drosophila boundaries form CTCF-independently. However, how CTCF-independent boundaries form and impact organismal development remains largely unexplored. Here, we assess genome folding and transcriptional regulation defects in fly embryos completely lacking the ubiquitous boundary associated factor Cp190. We find that sequence-specific DNA-binding proteins like CTCF and Su(Hw) directly interact with Cp190-containing core complexes and recruit Cp190 to form most promoter-distal boundaries. Cp190 is essential for early development and prevents regulatory crosstalk between gene loci that pattern the embryo. Cp190 is thus currently the major player in fly boundary formation and function, revealing that diverse mechanisms evolved to partition genomes into independent regulatory domains.