In his "Dialogues of Discovery" talk at Janelia on February 26, 2014, HHMI investigator Jeremy Nathans will explore the diverse ways in which color vision has evolved.
- The "Dialogues of Discovery" Lectures at Janelia are free and open to the public, but tickets are required for admission.
- Nathans has been an HHMI investigator at Johns Hopkins since 1987.
- He uses molecular genetic approaches to study the development of the mammalian retina.
Jeremy Nathans, a Howard Hughes Medical Institute investigator at Johns Hopkins University, will deliver a public lecture at Janelia titled, “The Evolution of Human Color Vision.”
Nathans will speak on Wednesday, February 26, 2014, at 7 p.m. The lecture, part of an ongoing series called “Dialogues of Discovery at Janelia Farm,” is free and open to the public, but tickets are required for admission. Seating is limited to 250 people. Doors will open at 6:30 p.m.
Tickets will be available on a first-come, first-served basis, beginning at noon EST, Friday, January 17. At that time, tickets can be ordered at https://tix.extremetix.com/Online/Janelia
Nathans, who has been an HHMI investigator at Johns Hopkins since 1987, uses molecular genetic approaches to study the development of the mammalian retina and embryo. Color vision is found throughout the animal kingdom. It is even found in a primitive form in some plants and bacteria. Nathans’s lecture will explore the diverse ways in which color vision has evolved, with an emphasis on its evolution in humans and other primates. He will also discuss inherited variations in human color vision, which represent some of the most common variations in sensory function in our species.
Nathans’s interest in vision was sparked by a career-altering seminar on the mammalian visual system that he took while a graduate student at Stanford University. “I was so struck by the beauty of the visual system that I asked my thesis advisor, David Hogness, if I could work instead on the genetics of human color vision,” he recalls.
Hogness, a molecular biologist working on fruit flies, was then developing the new molecular techniques needed to probe complex genomes, including the human genome, and he appreciated that this represented an interesting scientific question.
Although humans are in many ways an unsatisfactory experimental organism, color vision is a trait that is highly developed in primates. “At the time there was a detailed understanding of human color vision at the psychological level, but little was known about its molecular basis,” says Nathans. “The time was ripe for exploring it.”
Nathans’s efforts to clone the genes for the three color-sensing receptors pushed the technological envelope. The retina contains two kinds of light-sensing cells: rods for dim light vision and cones for color vision. The cones come in three varieties, each containing one type of receptor, which respond most efficiently to red, green, or blue light. Nathans based his search for the color receptor genes on the idea that the light-absorbing receptor found in rods—rhodopsin—was similar to the color vision receptors. To test his theory, he first needed a DNA probe that would bind to the rhodopsin gene.
For two years Nathans was stuck at the first step in the process. “That’s a tough place to be. If you haven’t found what you are looking for, you don’t know if it’s a foot away or a mile away,” he says. Eventually, he succeeded in isolating the rhodopsin gene and, with additional work, the three genes coding for the color vision receptors. With the cloned genes in hand, Nathans was then able to demonstrate that variations in the color receptor genes are responsible for the common anomalies of human color vision, referred to as color blindness.
“What is really striking about the human visual system is how beautifully it works,” says Nathans. “For example, we can distinguish well over one hundred thousand distinct colors based on the relative activities of just three receptors—it’s quite amazing.”
Nathans’s interest in the mammalian visual system extends to clinically significant problems, such as retinitis pigmentosa (a degeneration of the periphery of the retina) and macular degeneration (a degeneration of the center of the retina).
A member of the National Academy of Sciences and the Institute of Medicine, Nathans has received numerous awards and honors, including the Initiatives in Research Award (National Academy of Sciences), the Champalimaud Prize for Vision Research (Champalimaud Foundation), and the Newcomb-Cleveland Prize (American Association for the Advancement of Science).
Recent speakers in the “Dialogues of Discovery” series have included Cori Bargmann, HHMI investigator at Rockefeller University; Jennifer Tour Chayes, Managing Director at Microsoft Research; Sean Eddy, Eric Betzig, and Karel Svoboda, laboratory heads at Janelia; Sir Paul Nurse, President of The Royal Society; Roger Perlmutter, President of Merck Research Laboratories; and Leslie Vosshall, HHMI investigator at Rockefeller University.