������Ƶ

An international team of researchers led by Associate Professor Ken Welch will explore in greater detail the metabolic marvels of the hummingbird thanks to a $1.6 million grant from the .

The goal of the project is to bring together researchers with expertise in molecular biology, genomics, molecular biophysics and physiology in order to gain a more complete picture of hummingbird metabolic performance from the molecular level all the way up to the bird itself.

“Hummingbirds operate at the extremes of physical and metabolic performance,” says Welch, a biology professor at the University of Toronto Scarborough. “To fuel their high-energy hovering flight, hummingbirds can break down ingested sugars at rates 55 times that of non-flying mammals.

“Even more impressively they can directly fuel their intense exercise completely with fructose, which is something no other vertebrates can do.”

Almost all research that links molecular variation to metabolic performance is done on traditional biomedical model systems like yeast, fruit flies, mice and rats. The metabolic enzymes in hummingbirds that break down glucose and fructose while also storing fat operate at some of the highest efficiencies known to exist. But as Welch points out, a lot remains unknown about the adaptations in enzyme function and regulation in these birds.

“Hummingbirds are also insulin-insensitive, which means the classical regulatory mechanisms at work in other vertebrate groups, including humans, do not function in hummingbirds,” he says.

The ultimate hope is to better understand mechanisms underlying the diversity of metabolic physiology in the animal kingdom, and maybe even reveal novel insights that can help in understanding human metabolic physiology and disease as well, adds Welch.

The team, which also includes researchers from Johns Hopkins University and the Center for Cooperative Research in Biosciences in Spain, will bring an interdisciplinary approach to both field and controlled lab studies as part of the project.

The Human Frontiers in Science Program offers grants to teams of researchers collaborating on significant scientific questions. An emphasis is placed on unique projects that bring together scientists from different backgrounds to focus on particular problems in the life sciences.