Research

Phenotypic plasticity in pea aphids

I work on the evolution of phenotypic plasticity and the response of organisms to environments using the pea aphid Acyrthosiphon pisum. Asexually-reproducing (i.e., clonal) pea aphid females display a developmental plasticity for wing phenotypes that is transgenerational: mother aphids sense environmental cues (conspecific density) and direct their offspring to develop as winged or wingless, with winged forms produced more frequently in crowded environments. I leverage variation in this system order to better understand the nature and evolution of plasticity.

Variation in the strength of wing plasticity

Some pea aphid lines display high plasticity (a large increase in the proportion of winged offspring) when exposed to crowding, accompanied by a strong transcriptional response, while others display low plasticity (little to no change in the proportion of winged offspring) and little to no transcriptional response (see our 2021 paper).

My recent paper demonstrated that variation in the strength of plasticity is heritable and appears to have a multigenic basis. I employed a laboratory cross between a high plasticity line and a low plasticity line and pinpointed one of the contributing loci.

In a second recent paper, we examined an association mapping population and detected a candidate plasticity variation locus as well as effects of an aphid endosymbiont on the strength of plasticity. In contrast, we found no association between the strength of plasticity and body color - a previously rumored connection.

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