Researchers from the University of Akron discovered leptin in peregrine falcon, mallard duck and zebra finch.
In their "Discovery of the Elusive Leptin in Birds: Identification of Several 'Missing Links' in the Evolution of Leptin and its Receptor," published on March 24, 2014, in the journal PLOS ONE, UA researchers reveal their findings.
UA Professor of Biology R. Joel Duff made the initial discovery by comparing ancient fish and reptile leptins to predict the bird sequence. Duff, along with undergraduate students Cameron Schmidt and Donald Gasper, identified the sequence in multiple bird genomes and found that the genomic region where leptin was found is similar to that of other vertebrates. Jeremy Prokop, a former UA Integrated Bioscience doctoral student who initiated the project, then constructed computer models of the bird leptin's three-dimensional structure and performed bench experiments to show that the bird leptin can bind to a bird leptin receptor.
Richard Londraville, research team member and UA professor of biology, said that the search for leptin in birds has been a bit of a race among scientists.
"It has been a pretty big deal because people wanted to study leptin in birds for the poultry industry, for instance, to develop faster growing and tastier chicken," Londraville said, noting that, interestingly, leptin has yet to be discovered in chickens, perhaps because their gene structure varies from that of other birds.
Robert Dores, editor-in-chief of the journal General and Comparative Endocrinology, said the discovery represents a significant turning point in leptin study.
"This study now sets the stage for future studies on the evolution of leptin function ... and reinforces that studies on hormone sequences should be complemented by hormone receptor modeling studies," said Dores, a University of Denver professor of biological sciences. "The world of comparative endocrinology has entered the 21st century."