Fig. 2

Complex gene family hierarchies. Three hierarchical directed acyclic graphs (DAGs) which show the complex hierarchy levels centred around a highlighted family typical of many gene families within our resource. The gene family hierarchy map for ‘Serine/threonine phosphatases’ (a) follows a simple tree-like structure. However, the maps for the ‘Cholinergic receptors, muscarinic’ (b) and ‘HAD Asp-based protein phosphatases’ (c) families show that our maps are DAGs and do not always follow a tree-like structure