Redox Signals Romance

Abstract

Male dragonflies of certain species send a clear sign when they’ve reached sexual maturity: They turn bright red. A group of scientists in Japan now reports that redox chemistry underlies this so-called nuptial coloration (Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.1207114109). This is the first time redox-mediated body color change has been discovered in animals. “Unlike most insects, dragonflies change their color pattern in their adult stage, although the molecular mechanisms are poorly understood,” says Ryo Futahashi of Japan’s National Institute of Advanced Industrial Science & Technology, who spearheaded the research. “I simply wanted to know how these color patterns developed.” Futahashi and his coworkers extracted the ommochrome pigments from the epidermis of three species of dragonfly—Crocothemis servilia, Sympetrum darwinianum, and Sympetrum frequens. Males of these species turn a vibrant red when they reach sexual maturity, whereas females and immature males are a dull yellow. The researcher...