How development forms specific function: the highly unusual visual system of diving beetle larvae.

University Of Cincinnati Main Campus, Cincinnati OH

Investigators

Abstract

A fundamental question in biology is whether particular genes serve the same function in all animals. Eyes are a good system to address this type of question because there is such a diversity of eye types in the animal kingdom. There are many genes that are known to be important for both vertebrate and invertebrate eye development, but the eye genes that have been studied have only been studied in a very few organisms. So, it remains unclear how specific eye genes contribute to eye diversity. To address this question, the PIs have developed tools allowing them to investigate the development of the functionally complex, image-forming eyes of Sunburst Diving Beetle larvae. The beetle larvae eyes are quite different from the commonly studied fruit fly eyes and, in some ways, are more like vertebrate eyes. In this project, the PIs will compare genes for eye functions in these animals to see what is common and what is different between the two eye systems. The goal of the project is to understand the molecular basis for functional and structural eye diversity. This project will provide opportunities for training high school, undergraduate and graduate students to carry out molecular and physiological research. In addition, monthly outreach activities at the nearby Cincinnati Zoo and Botanical Garden (which houses a large Sunburst Diving Beetle display) will allow the research group to widely disseminate their findings and foster awareness of the value of conducting basic comparative research. Preliminary data from this research group suggest that many key genes are present in the eyes of beetles and flies, pointing towards fundamental molecular mechanisms of wide interest. However, there are informative differences in regards to when and where key genes are active. To investigate this further, the PIs will analyze tissue-specific gene and protein expression profiles (which is only possible in the very enlarged beetle eyes) and determine when and where key eye development genes are expressed within these eyes. In addition, using a gene knock-down approach in the beetle (Thermonectus marmoratus), developed in the lab, and accompanying state of the art genetic tests in the fruit fly (Drosophila melanogaster), different factors will be functionally dissected to compare and contrast the roles of genes associated with Drosophila eye and photoreceptor specification, photoreceptor function and lens development.