Fruit Fly Lab

The human retina is full of photoreceptor cells, cells that detect light, that are essential for proper vision. These cells contain the protein, rhodopsin, that enables them to detect light. When exposed to light part of these proteins detach from the phospholipid bilayer and enter the cell to be either destroyed or recycled to form more rhodopsin. However, the process by which rhodopsin is recycled has been mostly unknown until now. Similar processes are used in other cells to maintain the large surface areas they need to function, such as cells in the gut and lungs. This research relates to biology as it studies the changes in cells required to maintain homeostasis, a state of internal regulation required by all living organisms. This information is not only relevant to biology, but also to the general community as it could be used to better understand and treat macular degeneration, a disease in which vision and light sensitivity is gradually lost.
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In the experiment, researchers sought to discover how cells in the retina restore their surface membranes and proteins to maintain homeostasis by recycling rhodopsin. They decided to use the photoreceptor cells in the eyes of fruit flies as model systems for the experiment due to their large light sensing regions. In order to test their hypothesis, the researchers bred fruit flies with diminished levels of the enzyme phospholipase D. They then examined the surface areas of the photoreceptor cells after the flies were exposed to bright light and compared them to wild type flies with normal levels of phospholipase D. The photoreceptors of the mutant flies gradually diminished in size leading to difficulty sensing light. When mutant flies were bred with no phospholipase D, their retinas degenerated and the flies went