Pearring Lab’s Image “Seeing the Light” was accepted for the 2020 BioArtography Collection.
“Light that enters the eye is captured by rod and cone photoreceptor cells in the retina (located in the back inner surface of the eyeball). These cells are able to convert light into electrical information that can be interpreted by the brain. The photoreceptor cell has a light sensor that is filled with thousands of membrane layers. Like layers of paint, this arrangement increases the chance that a photon of light is absorbed by the visual pigment residing in these membranes. To maintain the health of this compartment, these membranes must undergo continuous renewal. Like a conveyor belt, new membranes are added at the bottom while old ones are removed from the top. In this image a handful of rod photoreceptors, in yellow, have been genetically activated to reveal new membrane addition, while the rest of the rod population is labeled in blue.”
The entire 2020 Juried Collection of 18 images can be found at the U-M BioArt Website.
Our image was also included in a recent Michigan Today article featuring Deb Gumucio, co-founder and director of U-M BioArtography Project, discussing the imagery of the coronavirus.
Hanh Truong is a graduate student in the Cellular and Molecular Biology Program. She completed her undergraduate degree from the University of California, Santa Cruz. She is working on a project to understand the organization of the transition zone in the ciliary outer segment of photoreceptor cells and how it is altered during retinal degeneration.
Nafisa Nuzhat is a graduate student in the Department of Cell and Developmental Biology. She completed her undergraduate degree from the University of Michigan. She is working on a project to elucidate the molecular players engaged during early stages of photoreceptor ciliogenesis.
The Pearring lab was awarded a 3 year Research Award from the E. Matilda Ziegler Foundation For The Blind to support a project titled, “Photoreceptor Outer Segment Regeneration: Understanding the Molecular Programs and Dynamic Cellular Processes for De Novo Biogenesis”. This proposal employs molecular genetic techniques and innovative advanced microscopy to uncover the molecular and cellular programs involved in daily outer segment renewal and then applies this knowledge to transform a primary cilium into a large, membrane-dense, light-sensing organelle.
Our vision begins in the ciliary outer segment compartment of retinal photoreceptor cells where light is captured and transformed into a neuronal signal. Unlike other primary cilia, the outer segment is 50-fold larger and filled with hundreds of tightly-stacked disc-shaped membranes, increasing light sensitivity. As light detectors, photoreceptors are highly susceptible to phototoxic damage, which is alleviated by continuously replacing their outer segment on a daily basis. Like a conveyer belt, outer segment renewal occurs by adding new disc material to the base, while old discs at the tip are shed and taken up by neighboring retinal pigment epithelium cells. Understanding the underlying mechanisms governing outer segment renewal will provide valuable insight into how to build and regenerate this light-sensing organelle following injury or disease.
