Conservation of sex-biased gene expression between D. melanogaster and D. ananassae. Panel A shows the overall conservation of sex-biased expression between the two species. Panel B shows the conservation of the specific sex-bias classes, with the first letter indicating the bias in D. ananassae and the second letter indicating the bias in D. melanogaster. "M" indicates male-biased, "F" indicates female-biased, and "U" indicates unbiased expression. The area of the chart taken up by each category indicates the percentage of genes falling into that category. The number of genes in each category is given in parentheses.
Grath et al. BMC Evolutionary Biology 2009 9:291 doi:10.1186/1471-2148-9-291