Figure 1

Graphical representation of an InParanoid ortholog cluster with the outparalogs outside the cluster indicated. The seed orthologs from the different species are denoted A1 and B1 and they are the bi-directional best Blast hits. Their similarity score (S) is shown. Inparalogs with score S or higher to the seed ortholog are inside the circle with radius S and hence, belonging to the cluster. Inparalogs are added to the cluster independently for each species. The sequences with a lower score than S are outside the cluster and classified as outparalogs. To generate the so-called extended cluster, for each inparalog in the cluster, the closest outparalog (non-ortholog or non-inparalog) from each species is added.