Multiple sequence alignment of the rodent CENP-O C-terminal domain. Schematic shows α-helices and β-sheets (gray boxes) and loops and turns (gray lines). Asterisks indicate highly likely adaptive residues (magenta, probability ≥ 0.9), less likely adaptive residues (blue, probability ≥ 0.5), and residues that differ between mouse and rat but do not evolve under positive selection (black). Magenta arrows indicate residues swapped in the experiment. Alignment: dark gray: highly conserved residues, gray: less conserved residues, white: non-synonymous substitutions.