Fall 2017 Biology Seminar Series: Joseph Corbo
Biology professor Jens Rister will be bringing in guest speaker Joseph Corbo from Washington University Medical School. His talk title is "Photoreceptor Reprogramming and Seeing (infra)red." The abstract is as follows:
"This talk consists of two parts. In the first, I describe our efforts to develop a novel therapeutic strategy for the treatment of blindness via cellular reprogramming of photoreceptors. We have found that acute knockout of the cell fate determinant, Nrl, in the adult rod photoreceptor reprograms rods into cells with a variety of cone-like molecular, histologic and functional properties. We show that this conversion also rescues photoreceptors from degeneration in a mouse model of retinitis pigmentosa. This rescue is the first therapeutic effect that has ever been achieved via direct cellular reprogramming in the mammalian central nervous system.
In the second part of the talk, I describe how some vertebrate species have evolved means of enhancing their color vision and extending it beyond the human range. I present two such evolutionary adaptations. First, I describe how fish convert vitamin A1 into A2 to extend their vision into the infrared. This conversion is achieved by the expression of Cyp27c1, a member of the cytochrome P450 family of enzymes. Knockout of Cyp27c1 in zebrafish abrogates production of vitamin A2, reducing the animal’s ability to see and respond to infrared light. Second, I show how birds enhance their ability to discriminate red colors by depositing ketocarotenoids in the oil droplet of their red cone photoreceptors. This clever adaptation is mediated by expression of another P450 enzyme, CYP2J19, which converts yellow yolk carotenoids into red ketocarotenoids specifically in the red cone. Interestingly, we find that this same enzyme mediates the formation of the ketocarotenoids used by red birds, such as the cardinal, to pigment their feathers. Taken together, these studies demonstrate a previously unanticipated role for cytochrome P450 family members in enhancing vision in the red and infrared portions of the spectrum."
For disability-related accommodations, including dietary accommodations, please visit www.ada.umb.edu two weeks prior to the event.