Face of a Frog: Time-lapse Video Reveals Never-Before-Seen Bioelectric Pattern
Source: now.tufts.edu
For the first time, Tufts University biologists have reported that bioelectrical signals are necessary for normal head and facial formation in an organism and have captured that process in a time-lapse video that reveals never-before-seen patterns of visible bioelectrical signals outlining where eyes, nose, mouth, and other features will appear in an embryonic tadpole.Video from: YouTube.com
The Tufts research with accompanying video and photographs will appear July 18 online in advance of publication in the journal Developmental Dynamics.
The Tufts biologists found that, before the face of a tadpole develops, bioelectrical signals (ion flux) cause groups of cells to form patterns marked by different membrane voltage and pH levels. When stained with a reporter dye, hyperpolarized (negatively charged) areas shine brightly, while other areas appear darker, creating an "electric face."
"When a frog embryo is just developing, before it gets a face, a pattern for that face lights up on the surface of the embryo," said senior author Dany S. Adams, Ph.D. Adams is a research associate professor in the Department of Biology in the Tufts School of Arts and Sciences and a member of the Tufts Center for Regenerative and Developmental Biology. "We believe this is the first time such patterning has been reported for an entire structure, not just for a single organ. I would never have predicted anything like it. It’s a jaw dropper."
Tufts Post Doctoral Associate Laura N. Vandenberg, Ph.D., was first author of the paper entitled "V-ATPase-dependent ectodermal voltage and pH regionalization are required for craniofacial morphogenesis." Ryan D. Morrie, a biology major in the School of Arts and Sciences, was second author.
Scientific Serendipity
The discovery was a case of scientific serendipity. Adams has spent years studying bioelectrical patterning and left-right developmental differences. Her frequent research tool is a camera hooked up to a microscope that sends images to a computer.One evening in September 2009 Adams was making time-lapse movies of early stage tadpole development. The images were coming out particularly clearly—no small achievement when filming tiny living creatures. She decided to leave the camera on overnight even though she anticipated that as the developing embryos began to move, the images would likely become too blurred to be useful.
When Adams arrived the next morning, the image on the computer monitor was out of focus as expected. But when she finished processing the rest of the images, she found they were clear. The movies were, she says, "unlike anything I had ever seen. I was completely blown away. I think I thought something like, ’OK, I know what I’ll be studying for the next 20 years.’"
The imagery revealed three stages, or courses, of bioelectric activity.
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Read the full article at: now.tufts.edu
