Under-representation of intrinsic terminators across bacterial genomic islands: Rho as a principal regulator of xenogenic DNA expression

► Consistent under-representation of intrinsic terminators across genomic islands. ► Genomic islands seem to be hotspots for Rho-dependent termination. ► Bacterial genomes from diverse phyla display this conserved feature. ► Rho factor-based defense mechanism that silences spurious gene expression.