Figure 1

Expression bias for male-enriched genes is greater than expression bias for female-enriched genes. Histogram showing the distributions of fold change values for female-enriched (red) and male-enriched (blue) genes. Recall that our differential expression criteria revealed 2512 female-enriched and 3387 male-enriched genes. Each observation represented in this graph is a mean across four fold change values, corresponding to the four different absolute expression analyses. Arrows at x-axis termini represent distribution tails, which are not shown. These tails (approximately 200 observations each) were omitted for ease of graphical representation, and their absence does not affect the interpretation of the histogram. Comparison of the two distributions reveals that male-enriched genes are more frequent at higher fold change intervals, relative to female-enriched genes, and a Mann-Whitney U test formally confirms higher fold change values for male-enriched genes (p < 0.001).