Pea aphid wing plasticity variation has a multigenic basis.

Phenotypic plasticity, the ability of a single genotype to produce a range of phenotypes in response to environmental cues, can exhibit genetic variation like any trait. Discovering the genetic basis of plasticity and plasticity variation is critical to understand how populations will respond to the ongoing environmental challenges brought about by, for example, climate change. Here, we investigate the genetic basis of the pea aphid (Acyrthosiphon pisum) wing plasticity variation. In this species, genetically identical wingless (highly fecund) and winged (dispersive) individuals are produced by pea aphid mothers in uncrowded versus crowded environments, respectively. We focus specifically on the genetic basis of the propensity to produce winged individuals in response to crowding. We crossed a low to a high plasticity line and examined plasticity variation in backcross progeny (F1 × low parent), finding that differences between lines had a strong genetic component and that multiple loci likely contribute to this variation. Transcriptional profiling revealed a candidate gene, yellow-h, which was found within a genomic locus contributing to plasticity variation. Overall, we provide novel information about the genetic basis of an ecologically relevant trait and contribute to the growing literature recognizing the importance of understanding the genetic basis of plasticity variation.