5′ Boundary structure and methodology. (A) Sequence logo for Cryptococcus gattii species WM276, showing the typical restriction of 5′ consensus sequences to positions +1 through +6. (B) Degree of change for sites +3 through +16 for external branches leading to three representative species. Rates of change at positions +8 through +16 are much higher than at positions +3 through +6 and constant across sites, consistent with lack of selection for specific consensus motifs. (C) Illustration of method. For each nucleotide position +3 through +6, we studied boundaries at which the other three positions are conserved with sister and outgroup species (in this case, we study position +4, and thus require conservation at +3, +5, and +6).
