Tuesday, October 14, 2008

Visualizing the Embryo

The elephantine embryo loomed before him above the holostage, its triangular head folder over with two round bulging eyes. "This is the first month, a critical stage for Eyeless," Onyx explained. "As you can see, the eyes are normal with this allele."

She stepped onto the holostage. The "skin" of the embryonic form puckered as her arms entered, and she stepped inside. Her hand rested lightly beneath he pulsating bulge of the heart tube, which had yet to develop separate chambers. She reached up into the head between the eyeballs, cupping them in her hands. "You can see the lens and cornea tissues are shaping up. Come on in," she urged.

~ Daughter of Elysium, Joan Slonczewski
For me, one of the most difficult aspects of embryology is envisioning the complex movement of cells in three dimensions. Sure, you can watch an embryo develop under the microscope - at least those that can fully develop in a petri dish like frog and fish embryos - but it is nearly impossible to follow the paths of individual cells. Now scientists at the European Molecular Biology Laboratory (EMBL) have created a tool that does just that.

New microscope technology has been used to track every cell of a zebrafish embryo for the first 24 hours of life, from one cell to 20,000 cells. You can download movies constructed from their image data (I used MPlayer to view them). The videos are gorgeous, but they are more than simply pretty to look at. According to the article published in Science, the images have provided new insights into the embryonic development of the heart and other organs.

Is this the interactive 3D model of science fiction? The press release claims that they have created the equivalent of "Google Earth" for embryonic development. That may be true if you have the Matlab software to visualize the original data, but the videos don't even meet that level of interactivity. I would love for the data to be integrated into a real Google Earth-like tool, which could be used to easily zoom in on and rotate the embryo, and which could run on any personal computer. I don't see why that couldn't be available in the near future. For the time being, though, I'm happy watching the movies.

(If you are having trouble seeing the movies, or find they are too large to download, PZ Myers has created a lower-resolution YouTube version.)

Article: P.J.Keller, A.D. Schmidt, J.Wittbrodt, E.H.K. Stelzer. Reconstruction of Zebrafish Early Embryonic Development by Scanned Light Sheet Microscopy, ScienceExpress, 9 October 2008

Image: Still images from the digital zebrafish embryo [left halves, colors encode movement directions of cells] compared to microscopy data [right halves] at different time points in development.


No comments: