Data from: The roles of growth regulation and appendage patterning genes in the morphogenesis of treehopper pronota

<p>Treehoppers of the insect family Membracidae have evolved enlarged and elaborate pronotal structures, which is hypothesized to involve co-opted expression of genes that are shared with the wings. Here, we investigate the similarity between the pronotum and wings in relation to growth. We show that the ontogenetic allometry of the pronotum is similar to that of wings in Membracidae, but not the outgroup. Using transcriptomics, we find genes related to protein synthesis and translation are mutually upregulated. These genes are implicated in the eIF2, eIF4/p70S6K, and mTOR pathways, and have known roles in regulating cell growth and proliferation. We show that species-specific differential growth patterning of the pronotum begins as early as the third instar. This finding suggests that co-option of appendage patterning genes must occur before the metamorphic molt. We propose that a network related to growth and size determination is the more likely mechanism shared with wings. However, regulators upstream of the shared genes in the pronotum and wings need to be elucidated to substantiate whether co-option has occurred. Finally, we<span> believe it will be helpful to distinguish the mechanisms leading to pronotal size from those regulating pronotal shape as we make sense of this spectacular evolutionary innovation. </span></p>