The pigment, rhodopsin, was recreated based on the scientists "inferring" its protein sequence.
Their findings, reported in the September issue of Molecular Biology and Evolution, offer the first look at a protein that has not been seen in 240 million years, and pave the way for scientists to study how the structure and function of vision pigments -- and ultimately other biologically important molecules -- have changed over the course of evolutionary time.
"Visual pigments trigger the critical first step in the biochemical cascade of vision in humans and other animals and obviously were present in now extinct species," says senior author Thomas P. Sakmar, M.D., head of Rockefeller University's Laboratory of Molecular Biology and Biochemistry.
"Recreating the inferred visual pigments of the archosaur ancestors in the laboratory should be a first step toward a better understanding what they could see -- and not see," adds Sakmar, an HHMI associate investigator.
In their journal paper, Sakmar and his colleagues report that archosaurs may have had a class of visual pigments that would support dim-light vision. "This is consistent with the intriguing though controversial possibility that nocturnal, not diurnal, life histories may have been the ancestral state in amniotes, which are birds, reptiles and mammals whose embryos are protected with a fluid-filled sac," says Belinda S.W. Chang, Ph.D., first author and research assistant professor at Rockefeller. "We are doing further biochemical studies on this recreated pigment to clarify this issue."