Relative expression between <i>D. simulans</i> and <i>D. sechellia</i> alleles and <i>Trans</i> regulatory divergence in humoral immunity genes.

Relative gene expressions were quantified by qPCR in parental and F1 hybrid larvae. The relative allelic expression in hybrids were estimated using proportions inferred from Illumina MiSeq sequencing of hybrid transcriptions for each gene, and the relative allelic expression between parental larvae were calibrated to half accordingly. (A) Relative allelic expressions between parental larvae and F1 hybrids under unchallenged (control), and infected (immune challenge imposed by injections of wasp homogenate) conditions. (B) Trans-regulatory divergence between D. simulans and D. sechellia in unchallenged and infected larvae, measured as the log2 ratio of relative D. simulans over D. sechellia expression. Error bars are 95% confidence intervals on model coefficient.