Conserved gene order at the nuclear periphery in Drosophila.

Whether higher-order chromatin organization is related to genome stability over evolutionary time remains elusive. We find that regions of conserved gene order across the genus Drosophila are larger if they harbor genes bound by B-type lamin (Lam) and Suppressor of Under-Replication (SUUR), two proteins located at the nuclear periphery. Low recombination rates and coexpression of genes in regions of conserved gene order do not explain the lower probability of disruption in these regions by genome rearrangements. Instead, we find a significant colocalization between evolutionarily stable genomic regions associated with Lam and sequences thought to regulate local gene expression, which have the potential to impose constraints on genome rearrangement. At least in the genus Drosophila, localization of particular genomic regions at the nuclear periphery is intimately associated with their long-term integrity during evolution.