This award provides funds to support two three-month research visits by Dr. Dorothy B. Rountree, Department of Biology, University of Louisville, for collaboration with Dr. Shin-Ichiro Takahashi, Department of Applied Biological Chemistry, University of Tokyo, and Dr. Katsuhiko Endo, Biological Institute, Yamaguchi University, Japan, on seasonal polymorphism in butterfly species. A goal of their research is developing a new, integrative model for endocrine regulation of seasonal polymorphism in these butterfly species.
Many butterfly species show different wing coloration or morphology depending on the season. The control of alternative seasonal phenotypes is interesting to developmental biologists, because external environmental cues, especially photoperiod, are changed by the insect into hormonal signals that alter internal developmental pathways. Two different kinds of hormones regulate butterfly seasonal polymorphisms: the neuropeptide Summer Morph Producing Hormone (SMPH) and the steroid molting hormones (ecdysteroids). Until recently, butterflies were thought to use either one hormone or the other to determine which phenotype to develop, but SMPH has been found in ecdysteroid-regulated butterflies and ecdysteroids can change phenotype in SMPH-regulated butterflies. Thus, the need for creating a new, integrative model for endocrine regulation of seasonal polymorphisms. In this project, the hypothesis that SMPH influences ecdysteroid receptor complex proteins will be tested in an SMPH-regulated Japanese butterfly, Polygonia c-aureum (the Asian comma). Part of the proposed research will take place at Yamaguchi University, Japan, in collaboration with Dr. Endo, who discovered SMPH, while another part will be conducted at Tokyo University, in the laboratory of Dr. Takahashi, whose techniques developed on vertebrate cells will be used on an insect peptide signaling system. This research will be mutually beneficial because of the principal investigator's expertise in the study of the different molecular forms of proteins in the ecdysteroid nuclear receptor complex. This project is supported under the Science Fellowship Program between the National Science Foundation and the Japan Foundation Center for Global Partnership. ***
