Split network showing reticulate evolutionary events of ILTV genomes.

<p>The network was obtained from the nucleotide sequences of Unique Long, Internal Repeat and Unique Short regions of ILTV genome using SplitsTree4 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0149529#pone.0149529.ref046" target="_blank">46</a>] based on the neighbor-net method [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0149529#pone.0149529.ref047" target="_blank">47</a>]. The Italian field strains (in red) and the vaccine strains (in green) are closely related to the American CEO vaccines; in the zoomed inset, the split separating the field strains from all the other genomes is highlighted in red, while the one grouping them to the American virulent strain 63140 is in blue.