Asymmetric evolution of protein sequence and expression pattern. Scatter plot for asymmetry in expression and sequence divergence of the WGD duplicate pairs. Only duplicate pairs where more than 20 amino acid substitutions were predicted in at least one of the copies are included (see Materials and methods and Table 1). Red circles indicate duplicates with asymmetric expression divergence as defined in Figure 3. The line indicates the linear regression. The sign of sequence divergence asymmetry indicates the consistency between sequence and expression divergence (that is, negative values refer to duplicate pairs where the faster evolving copy in terms of sequence is the slower evolving copy in terms of expression).