Figure 2: dsx RNAi reduces sex-biased gene expression across horned beetle tissues.
(a) Degree of significantly (Padj<0.05) female- (pink) or male-biased (blue) gene expression in control animals measured as log-transformed fold change in FPKM (x axis) plotted against the corresponding level of expression in dsxRNAi animals (y axis). Genes that did not have significantly sex-biased expression are plotted in grey. Blue line reflects equally sex-biased expression in control and dsxRNAi individuals. (b) dsxRNAi reduces the number of O. taurus genes exhibiting significant sex-bias in control individuals. The number of genes with significantly (Padj<0.05) female-biased (solid pink) or male-biased (solid blue) expression in control animals (total=4,285) was reduced ∼2.7-fold when assessed in dsxRNAi animals (pink and blue lines; total=1,596). (c) dsxRNAi females (pink lines) overexpress more genes relative to control females (solid pink) in head horns only, indicating that, in females, Dsx directly or indirectly suppresses the expression of downstream genes in that specific tissue. DsxRNAi males (blue lines) also overexpress as many or more genes relative to control males (solid blue), but do so across tissues, indicating that, in males, Dsx acts to directly or indirectly suppress the expression of downstream targets across a broader range of target tissues. In addition, in head and thoracic horns, control (solid blue) males overexpress many genes relative to dsxRNAi males (blue lines), suggesting that, in males but not females, Dsx also directly or indirectly activates the expression of many downstream targets. (d) Tissues analysed in this study were derived from 1st day pupae, and included brains (gold), genitalia (teal), thoracic horn (light green) and head horns (dark green).
