Estimated AT content at mutational equilibrium determined by full method.

Method involves consideration of all possible mutational classes and solving the relevant simultaneous equations, see Methods. “seq_depth” differentiates the samples into those sequenced with higher or lower depth by Zhang and colleagues [57]. “mut_size” refers to the approach by which the mutational matrix was generated, i.e., counting mononucleotide or dinucleotide mutations. “region” refers to 5′ ends (i.e., the first 20 codons following the start codon), gene cores (i.e., the rest of the CDS), intergenic (i.e., non-CDS mutations), or genomic (i.e., the whole genome including non-protein coding sequences). “pred_AT” is the predicted AT content at mutational equilibrium. “mean_boot_ATestimate” and “std” are the mean and standard deviation of repeating the nucleotide content estimate calculation (i.e., “pred_AT”) for 1,000 bootstraps. The data underlying this Figure can be found in https://doi.org/10.5281/zenodo.17378284. (CSV)