Snapshots of Life: The Dance of Development
Posted on by Dr. Francis Collins
|Credit: Amanda L. Zacharias and John I. Murray, Perelman School of Medicine, University of Pennsylvania|
This video may look like an aerial shot of a folk dance: first a lone dancer, then two, then four, until finally dozens upon dozens of twirling orbs pack the space in a frenzy of motion. But what you’re actually viewing is an action shot of one of biology’s most valuable models for studying development: the round worm, Caenorhabditis elegans (C. elegans).
Taking advantage of time-lapse technology, this video packs into 38 seconds the first 13 hours of this tiny worm’s life, showing its development from a single cell into the larval, or juvenile stage, with 558 cells. (If you are wondering why C. elegans doesn’t look very worm-like at the end of this video, it’s because the organism develops curled up inside a transparent shell—and after it breaks out of that shell, it squirms quickly away.)
Not only is this cool video among the winners of the Federation of American Societies for Experimental Biology’s 2013 BioArt competition, it shows some very cutting edge research. A team led by John Murray, an NIH-funded geneticist at the University of Pennsylvania in Philadelphia, produced this movie to study how various proteins control the fate of cells during C. elegans’ early development.
We can follow the process because the DNA inside the nucleus of each cell is tagged with green fluorescent protein. Just before a cell divides into two new cells, the DNA in its nucleus copies itself, which is why the amount of green seems to double in a bright flash. The process repeats itself time after time, as cells divide and the organism grows.
Towards the end of the video, you’ll notice flashes of red and yellow. These colors reveal that a transcription factor—a protein that switches genes on and off—has become active and is now initiating development of a particular cell or cellular process. In this case, the transcription factor is CEH-27, which is important for the development of the worm’s skin. The human counterpart of CEH-27 is a family of NKX2 transcription factors, which play a role in the development of the heart and gut.
Thanks to the DNA sequencing work carried out by the Human Genome Project, we know that homologs of about 35% of the genes in C. elegans are also found in humans and other mammals. So, it should come as no surprise that this creature provides us with a convenient laboratory model to learn more about the role of genes in choreographing the complex dance of development.
BioArt, Federation of American Societies for Experimental Biology
The Laboratory of John Murray, Perelman School of Medicine, University of Pennsylvania
BioArt 2013 Exhibit. The public can view an exhibit of the winning art at the NIH Visitor Center. Located in Bethesda, MD, the Center is open from 8:30 a.m.–4:30 p.m. M–F.
NIH Support: Eunice Kennedy Shriver National Institute of Child Health and Human Development; National Institute of General Medical Sciences