Accumulating data suggest that bacterial genes are co-regulated along spatial genomic domains, even when they do not share any transcriptionfactor, thus escaping classical regulation models. The LoToReG project aims at explainingthese observations through a novel ancestral form of transcriptional regulation based onthe activity of RNA Polymerase (RNAPol) on DNA, through the formation of coupledtopological-transcriptional domains. The objective is to develop a quantitativecomputational modelling of this basal regulation mode.