A clustering with six classes is required to determine the recipient species signature of E.coli. The main features are summarized in Table 1 . The potential donors of the 84 RNAfree atypical regions are given in Annex 6 (for a segmentation of the E.coli genome in terms of genes, see Annex 7). It is worth noticing that 56% of E.coli potential donors belong to the Enterobacteriales family. Segmentation in terms of genes is displayed in Annex 7. The analysis of this genome is particularly useful for the comparison with literature (see below).