Fig. 3

a. A typical IS associated to their neighbouring genes. Upstream (− 1) and downstream (+ 1) genes are relative to the genome sequence 5′-3′ orientation. The two IS-Gene couples (IG) for (− 1) or (+ 1) gene are indicated. When IS overlap a gene, the latter was denoted as 0. b. Types of IG shapes between IS and neighbouring genes. Arrows indicate the orientation of − 1 (downstream) and + 1 (upstream) genes. The four distinct IG shapes are: →IS→, Same orientation on Positive Strand; ←IS←, Same orientation on Negative Strand; →IS←, Opposite and Convergent orientation; ←IS→, Opposite and Divergent orientation. c. Distribution of IS-Gene (IG) shapes. When they exist, normal, underrepresentation and overrepresentation of IG shapes compared to a random distribution are displayed (with the corresponding color codes) for each IS family