![]() ![]() Thinking there’s nothing more fascinating than the hummingbird’s metabolism, the researchers applied to sequence the hummingbird liver, where much of the bird’s metabolic action takes place. The winner would receive enough laboratory supplies to get the project off the ground. The team caught a break when it heard of a Pacific Biosystems’ competition asking for 200-word proposals to sequence the most interesting genome. “You have to have already solved it before you can get at it.” adviser had studied under Hochachka.īut without previous data, it was difficult for the scientists to convince funders to invest in the plan. Wong built a team to tackle this sequencing issue, recruiting Timp, a longtime friend whose lab specializes in genetic sequencing technologies, and Kenneth Welch, Ph.D., a hummingbird expert from the University of Toronto Scarborough. So, the research essentially started from scratch. At the time, only two lone genes had ever been sequenced from the hummingbird. To untangle those questions, he needed the blueprints for how these enzymes are built: the hummingbird’s genetic code. The researchers hope that their work could yield insights into what goes wrong in human diabetes and obesity, by showing how hummingbird evolution solved has them. The next step in their project is to use the genetic information to study how those enzymes work. Scientists at Johns Hopkins, as part of an international collaboration, have sequenced the genetic code of the hummingbird liver, where many of these enzymes live. To process that high volume of sugar, hummingbirds have evolved a metabolism 77 times faster than a human’s, made possible by hyper efficient enzymes. They need to eat almost constantly, maintaining blood sugar levels high enough to cause serious disease in human. Hummingbirds burn massive amount of energy each day in order to sustain their rapid wingbeat of up to 60-80 beats each second. How and why are these enzymes so efficient? What is it about their chemistry and structure that makes them so effective?įueling the Hummingbird’s Extreme Biology ![]() These proteins, called enzymes, seem to be supercharged in the hummingbird and able to break down sugars and fats with an efficiency dwarfing that of most other vertebrates. Hochachka’s work suggested that the likely mechanism behind the hummingbird’s extraordinary metabolism is related to proteins in its liver and muscles, which process fuel sources such as sugars and fats into energy. Wong stumbled onto this question when he read a series of papers from the 1980s out of the lab of University of British Columbia researcher Peter Hochachka, Ph.D. ![]() And we need to figure out why it’s so good for them, so we can understand why it’s so bad for us.” “I’m a good old-fashioned American boy - I love my white bread and Twinkies, but sugar is not good for humans,” says Johns Hopkins biomedical engineering researcher Winston Timp, Ph.D. Uncovering what makes the hummingbird’s metabolism so extraordinary could yield insights into what goes wrong in human metabolic disease and perhaps even novel ways to fight it. “Hummingbirds have solved two of the problems that humans are facing: obesity and diabetes,” says Johns Hopkins Medicine metabolism researcher G. William Wong, Ph.D. The hallmarks of late-stage human diabetes - kidney failure, blindness and stroke - appear completely absent. Yet considering the bird’s massive sugar binge, and its rapid weight gain and loss, there don’t seem to be biological downsides. As soon as they take off, they rapidly burn through those fat stores, at rates that put humans’ abilities to shame. Other sugars wind up in the liver where supercharged enzymes process them into fat that fuels the birds’ migration. Much of the sugar goes straight to their muscles to fuel the constant buzz of their wings and their rapid heartbeat, which can reach up to 1,200 beats per minute. They slurp down so much sugar that their blood sugar levels are high enough to kill or seriously hurt a human. ![]() To survive their migration, the birds rapidly pack on weight, as much as doubling it in a matter of days. To keep up the blistering pace of their flight, they need the human equivalent of over 150,000 calories every day. It’s fall on the East Coast, and the ruby throated hummingbird is preparing to follow the warm weather across the Gulf of Mexico, flying hundreds of miles without stopping for food. Their aerodynamic bodies seem to hover in the air, and the rapid buzz of their wings - up to 80 beats per second - creates a vague blur. They flit from flower to flower, sucking up all the nectar and small bugs they can find. ![]()
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