Figure 2. Distribution of the nuclear-basket components and Mad1/Mad2 proteins among eukaryotes. Homologs of the known constituents of the nuclear basket of animals, fungi and Trypanosomes as well as Mad1 and Mad2 proteins were searched in various eukaryotic groups using the BLAST and HMMER software. Positive hits (in gray) were verified by reverse BLAST. Two most preferred positions of the root within the phylogenetic tree of eukaryotes are marked with a star. While the root is traditionally placed between the “unikonts” (animals, fungi, and amoebozoa) and the remaining taxa, an alternative hypothesis suggests the root of eukaryotes lies within the group Excavata close to kinetoplastids.