Biology professor asks the big questions in life
University of Denver professor Todd Blankenship asks the “big questions” in life. For instance: Why do we look like we read more…
University of Denver professor Todd Blankenship asks the “big questions” in life. For instance: Why do we look like we do? How do humans and animals emerge from a single, mostly round cell into the shapes that we take? How do our emerging, “programmed” cells line up in the correct places to make us look like humans or dogs or fruit flies?
“If you look at a human being, every human has a very stereotypical shape,” Blankenship says. “We’ve got a head up at one end, feet at the other end. We’ve got two limbs up top, two limbs at the other end.”
To study these fundamental mysteries of biology, Blankenship and his students use a high-speed powerful microscope that peers into developing fruit fly embryos and photographs the cells as they scurry into position. They actually watch cells as they arrange themselves. Cells destined to be part of the head migrate to one end. Cells tagged for tail duty migrate to the other.
“If you look at almost any higher animal, we’re elongated along one axis. We’re elongated from head to toe, that’s our long axis. That poses a really interesting question, because we almost always start out as a sphere of cells, and then somewhere along the line that sphere has to turn into something that’s long along one axis,” Blankenship says. “This is something that almost every higher animal is going to have to do.”
To study this cellular choreography — known as cell polarization — Blankenship and his students manage a massive hive of fruit flies. Not the evil, disease-spreading variety, but benign breeds that peacefully eat corn mush and lay eggs. Their rapid life cycle, springing from egg to fly in about eight days, means researchers have a steady supply of embryos to put under the spinning disk confocal microscope.
Students prep the budding bugs by fusing DNA from jellyfish to the flies, tagging proteins with material from the jellyfish that will glow when “excited” by laser light. Then the embryos are placed on the microscope and subjected to laser light. Scientists can then identify and photograph specifically tagged cells as they move about, changing what was once a tiny grub into a fly.
“There are molecules that tell a cell, ‘You’re going to be at the head of the fly,’ and molecules that tell a cell, ‘You’re going to be at the end of the fly,’” Blankenship says. “What we’re looking at is one level down to see how once they receive those instructions, the body tells the cells, ‘If you’re going to be the head, we have to move all these cells up here, and if you’re going to be the tail we have to move you down here.’ That’s the huge black box that developmental biologists do not know, and that’s what we’re trying to figure out.”
Blankenship says the beauty of his lab’s work is that it’s never done, and it’s basic research, driven by the desire to understand how things work. Blankenship’s team focuses simply on understanding the underlying rules of cell behavior. Just learning how cells do what they do can open doors to understanding how similar events go wrong in the development of human cancers and other cell malfunctions.
“All your work leads to many more questions,” he says. “At some point maybe we’ll know the atomic behavior of every protein that’s involved and we’ll say we’re done. But I think we’re going to be in business for a long time.”
Blankenship spoke about his research at TEDxDU 2011. Watch a video of his talk.