Transparency is a remarkable and widespread characteristic of many biological tissues. In addition to occurring in all eyes, transparent tissue is found in many oceanic animals where it functions as the ultimate form of camouflage. Remarkably little is known, however, about how this trait is achieved. This project will investigate the basis of transparency in eyes and muscle using mathematical models, new microscopy techniques, and biochemical analyses. Transparent muscle will be analyzed in two different species of glass catfish and compared with the muscle of opaque fish. The lenses of the eyes of squid and octopus will also be examined. This project will provide fundamental new insights into the structural and biochemical alterations that are used by animals to achieve transparency. Such insights have important implications for understanding the costs of transparency in many oceanic species and in the development and prevention of cataracts and corneal opacities in humans. In addition, understanding how light travels through tissue is important not only for transparent tissues, but for non transparent tissues as well, with important implications ranging from satellite-based analyses of large-scale changes in the ocean to non-invasive optical methods for the diagnosis and treatment of skin disorders. This project also trains female graduate student in biophysics, a subject with very few women. In addition to the usual technical articles, the results will be presented in at least one popular science magazine. Finally, the project will strengthen ties between Duke University and the University of North Carolina at Chapel Hill, neighboring universities that interact less than they should.
