Dissertation Research: Geographical Variation in Developmental Genetic Control of Polyphenism

University Of California-Irvine, Irvine CA

Investigators

Abstract

Animals can vary in appearance or behavior between generations in response to environmental changes; this is called polyphenism. Polyphenism occurs frequently and allows animals to use existing genes in different ways to be better adapted to their environments, but very little is known about it at the genetic level. Buckeye butterflies show seasonal wing color changes; that is, different generations within a population have different colors. Buckeyes are well suited to laboratory life but also geographically widespread and exhibit tremendous color variation. Wing color changes are thought to enhance camouflage in seasonally changing foliage; but buckeye species are found in highly seasonal temperate forests, arid Mediterranean habitats, and relatively aseasonal tropical habitats. How polyphenism may vary between buckeye species in different climates to allow increased survival in their environments is unclear. The research questions are: (1) What geographical variation exists for wing pigments between color morphs from different regions? (2) What temperature and day-length thresholds trigger the different color morphs in different regions? and (3) What gene expression changes are associated with the different wing colors? Chemical analyses, controlled environment manipulations, and modern genetic methods will be used to provide an integrative picture of molecular and environmental regulation of the colors. The results will provide a better understanding of how gene regulation can affect the external appearance of animals. Through this project undergraduate students will be mentored and novel results and methods will be disseminated via publications and meeting presentations. The PIs will also conduct outreach to K-12 teachers and students.