Project Description :
The Nijhout Lab is looking for undergraduates interested in developmental and evolutionary biology research. This position will work on elucidating the causal mechanisms of size and shape variation in Lepidopteran wings using the common buckeye butterfly Precis coenia and the tobacco horn worm Manduca sexta as model organisms.
In Lepidopterans, wing development occurs through temporal patterns of cell divisions, which gives rise to the size and shape of wings. Growth of wing imaginal disks is dependent upon the hormones ecdysone and insulin. The size wings attain seems to be dependent upon the duration these hormones are secreted as well as the relative expression of ecdysone and insulin receptors.
The outline shape of the wing is also determined by a mechanism that seems to be unique to Lepidoptera. This mechanism is called the "cookie-cutter" mechanism because the outline of the wing is determined by the removal of cells through apoptosis on the distal part of the wing, actually cutting out the shape of the wing. This mechanism is used to create the tails on hindwings seen in swallowtail butterflies and Luna moths and many other unique wing morphologies in butterflies and moths. How this mechanism proceeds is completely unknown.
Experiments analyzing wing size will consist of hormone and insulin manipulations through injections and infusions into larvae of Precis and Manduca. We will also perturb expression of hormone receptors through RNAi and CRISPR/Cas9. To elucidate how the cookie-cutter mechanism might be elicited, we will use Luna moths and attempt to determine how wing veins might signal apoptosis to occur in regions distal to the border.
Daily activities would include Luna moth husbandry, experimental set up/execution, and data analysis. We are looking for individuals who are excited to learn how to conduct research and interested in pursuing a career in science. Hours are flexible but please be willing to work at least 10 hours per week.