Extended Data Fig. 10: A model for specific OR compartmentalization and the generation of mutually exclusive phases that regulate OR gene choice.

a, b, Coincidence of LHX2 and LDB1 peaks with trimethylation of histone 3 lysine 9 (H3K9me3) enrichment may generate an OR-enriched molecular barcode that promotes specific interactions between OR gene clusters. c, In INPs, where OR compartments first form, Greek islands do not make specific contacts with each other. d, However, in mOSNs Greek islands specifically interact with each other through homotypic LDB1 interactions, forming a multi-enhancer hub that is segregated from the OR compartment. We hypothesize that OR compartments and Greek island hubs form incompatible liquid phases driven by HP1 proteins and the unstructured domains of LHX2 and LDB1, respectively. e, Upon deletion of Ldb1 (or Lhx2), the Greek island phase falls apart and the Greek islands become incorporated to the OR compartments, as in the INPs.