Download Making worms that glow in the dark

Making worms that glow in the dark
March 11, 2002
The capability to genetically engineer plants and animals so that they glow in the dark began in
1960 in the frigid waters of Puget Sound in the state of Washington. A team of scientists from
Princeton University visited the area to collect jellyfish specimens in an attempt to understand the
nature of their bioluminescence. Two years later the scientists, Osamu Shimomura and Frank
Johnson, published a paper describing the purification of "aequorin", the “chemiluminescent”
protein that they thought was responsible for the bioluminescent properties of the jellyfish
Aequorea victoria. In the paper, they also noted the existence of a companion protein that
exhibits a very bright, green fluorescence when exposed to ultraviolet light. It was an inauspicious
beginning for what was to become one of the most widely used and useful tools available to cell
biologists.
The molecule – which was dubbed Green Fluorescent Protein, or GFP – remained little more
than a scientific curiosity for thirty years. That changed in the 1990’s, however, when scientists
sequenced the gene that produces GFP and solved its crystal structure. In 1994, a group of
scientists inserted the GFP gene in the genome of C. elegans and found that it produced
fluorescent GFP molecules within the bodies of the transgenic worms. In the same year, some
other scientists performed the same experiment in E. coli. These results paved the way for the
use of GFP as a “reporter molecule” in a wide variety of living organisms.
Since 1994, the use of GFP has exploded. It has been used with many other organisms. In
addition to C. elegans, it has been used in the fruit fly, zebrafish, mouse and rabbit, among a
number of other species. In these cases, bathing the animals in a blue light induces the GFP
manufactured in their bodies to emit green light or to “fluoresce.” Biologists use genetic methods
to direct GFP expression to specific cells or to sub-cellular structures such as mitochondria or
synapses in neurons, making these structures literally “glow in the dark” so they can be seen
easily in a special fluorescence microscope. Because these “transgenic” animals are alive, GFP
labeling allows scientists to directly observe cellular processes as they occur. Different colored
GFP proteins can be used simultaneously to observe more than one object in a living animal. The
different colors include Cyan (CFP), green (GFP), yellow (YFP) and a red fluorescent protein
recently isolated from a species of coral (dsRed). Miller and Dave Piston1 collaborated with
Andrew Fire’s at the Carnegie Institute of Washington to develop methods for visualizing these
different colored fluorescent proteins in C. elegans. 2
- VU Additional Information
Matthew Herper, Biotech's Glowing Breakthrough, Forbes.com, 26 July 2001
http://www.forbes.com/2001/07/26/0726gfp_print.html
1
Associate Professor of Molecular Physiology and Biophysics ; Associate Professor of Physics
Miller, D. M., III, Desai, N., Hardin, D., Piston, D. W., Patterson, G.H., Fleenor, J., Xu, S.Q., and Fire, A.
(1999) A two-color GFP expression system for C. elegans. BioTechniques 26, 914-921.
2
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