Distribution of sex-bias biased genes in tissue-specific datasets. Proportion of testis- and ovary-biased genes found in each tissue-specific gene dataset. For instances, testis-biased expression is defined for genes with signal ratio between testis and ovary larger than two. We tested if the distribution of testis-biased genes as compared to that of the ovary-biased genes were different between the tissue-specific dataset and the entire genome. Significant deviations from genomic proportions (Chi-square with Yates correction) are indicated for tissue-specific datasets with minimal tissue-to-tissue signal ratio larger than twofold (***P < 0.001; **P < 0.01, *P < 0.05).