Figure 1.
Proportions of vertebrate genes in the four gene groups. For each vertebrate genome on the X-axis, the gene groups are represented, from top to bottom, by segments of a bar for the genes in V.MCL (genes can be found in at least one of the six invertebrate genomes with standard homology search criteria), in V.A50 (genes are not in V.MCL, but can be found in the eight invertebrates when the homology search criteria are relaxed), in VFProk (genes are in neither V.MCL nor V.A50, but can be found in fungal or prokaryotic genomes), and in Vonly (genes are in none of the above three groups).
