Figure 2.

Running average of M:F ratios on the Z chromosome and autosomes. Top: plot of the M:F ratio of individual Z genes in brain (black) compared with the expression genes for 18 autosomes (red) containing more than 200 genes. Bottom: the running average of M:F ratios (calculated as in Figure 1) for brain shows that the Z chromosome (black) has much more pronounced valleys and peaks than are found in the autosomes (red through blue).