Fig. 1.

Phylogenetic relation, geographic distribution, and experimental design to study divergence of gene expression in chemosensory tissues of H. cydno and H. melpomene. (A) H. cydno and H. melpomene split ∼1 Mya, but male H. cydno still occasionally hybridize with female H. melpomene, resulting in fertile hybrid males and sterile hybrid females. Genomic patterns of admixture reflect this hybridization, with a generally stronger signal of gene flow from H. cydno into H. melpomene. We sampled the antennae, legs, and mouthparts (labial palps and proboscis) of H. cydno and H. melpomene individuals from Panama (Gamboa) in order to study divergence in chemosensory gene expression. (B) The experimental design included five replicates for each combination of species, tissues (antennae, legs, and mouthparts) and life stage (males, mated, and unmated females).