Comparison of M:F ratios and expression levels of Z-linked genes to those of autosomal genes. (a) The average values of M:F ratios for autosome chr1-chr28, along with that of Z chromosome. Values are represented on log2 scale. (b) The distribution of the expression level of genes on autosome chr1 to chr28 and on chrZ in female (blue) and male (red). Values are represented on log2 scale. For simplicity, the W chromosome is not included. Chromosome 32 is not annotated and thus not included in this analysis.