Gene expression variability in Pieris rapae

Why are some organisms specialized, while others can survive under many conditions? This research tests the idea that patterns of gene expression in individuals are molded to specific environments through processes analogous to learning. This kind of mechanism should come with costs such as delayed breeding or fewer offspring, leading to tradeoffs associated with being a generalist. The proposed research will test these ideas using caterpillars of a crop pest species, the cabbage white butterfly. This species feeds on a wide range of plants in the mustard family, such as broccoli and canola. However, after an individual has experienced one food source, they do poorly if switched to a new food source, suggestive of a type of physiological memory. This research will test whether genetic differences in specialization between agricultural and nonagricultural populations are associated with differences in gene expression variability and associated reproductive tradeoffs. The expected results will have implications for understanding how crop pests adapt to monoculture crops, which, in many cases, may be selecting for more problematic pests.