Roland Piquepaille's Technology Trends
How new technologies are modifying our way of life


samedi 20 mars 2004
 

After introducing molecules of different colors in living cells, researchers at Cold Spring Harbor Laboratory were able for the first time to take movies showing how a gene can force a cell to make a protein. Genome News Network says this could help to discover why an anticancer drug works. The researchers think it would also help to design new drugs.

For the first time ever, researchers have captured on film how a gene goes about the business of directing a cell to make a protein.
Researchers at Cold Spring Harbor Laboratory in Cold Spring Harbor, New York, tagged different molecules different colors so they could see the process by which a living cell makes protein from DNA within its nucleus. The process is much more dynamic than they had imagined.

How did they perform this experiment?

David L. Spector and his colleagues designed a gene sequence that could be inserted into the human genome. Once there, it could be turned on, or activated, at will and the ensuing sequence of events could be directly visualized by labeling DNA, RNA, and protein different colors in living cells.
The movie first shows a tightly compacted region of DNA opening up as the gene is activated. RNA -- tagged yellow with a fluorescent protein -- appears first in the nucleus and then moves out to the cytoplasm, the region of the cell surrounding the nucleus. Ultimately, blue-colored protein appears in the cytoplasm in structures called peroxisomes.

This movie is available under the name "Visualizing the central dogma in living cells" from this page. But don't try it if you don't have a broadband connection: the file size is 11.8 MB for a duration of 7 seconds. Here is one shot from the movie. On the left part, here is the protein product encoded (in blue) (Credit: Spector Lab). You'll find more explanations on this page.

Central dogma in living cells

What can we expect from such a system?

Spector says his system can provide a direct view of gene expression and may help researchers understand what happens when things go wrong. He envisions inserting the easily visualized gene that he constructed into specific spots in the genome to get a clearer view of how genes are regulated in the context of a living cell.
"We might also use this system to see how small molecules such as anticancer drugs work in a living cell," says Spector. "We could get a direct view into whether a drug is shutting down gene activation or affecting the way RNA is processed. Ultimately this could help us do a better job at identifying and designing new drugs."

The research work has been published by Cell. Here is the abstract of this paper named "From silencing to gene expression: real-time analysis in single cells."

We have developed an inducible system to visualize gene expression at the levels of DNA, RNA and protein in living cells. The system is composed of a 200 copy transgene array integrated into a euchromatic region of chromosome 1 in human U2OS cells. The condensed array is heterochromatic as it is associated with HP1, histone H3 methylated at lysine 9, and several histone methyltransferases. Upon transcriptional induction, HP1alpha is depleted from the locus and the histone variant H3.3 is deposited suggesting that histone exchange is a mechanism through which heterochromatin is transformed into a transcriptionally active state. RNA levels at the transcription site increase immediately after the induction of transcription and the rate of synthesis slows over time. Using this system, we are able to correlate changes in chromatin structure with the progression of transcriptional activation allowing us to obtain a real-time integrative view of gene expression.

Sources: Nancy Touchette, Genome News Network, March 19, 2004; Cell, March 5, 2004


1:02:46 PM   Permalink   Comments []   Trackback []  


Click here to visit the Radio UserLand website. © Copyright 2004 Roland Piquepaille.
Last update: 01/11/2004; 08:57:29.


March 2004
Sun Mon Tue Wed Thu Fri Sat
  1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31      
Feb   Apr


Search this blog for

Courtesy of PicoSearch


Supported by
BigFitness.com

If you're tired to read about technology, it's time to take a break.
Try their exercise and fitness equipment.
Read more


Personal Links



Other Links

Ars Technica
Bloglines
BoingBoing
Daily Rotation News
del.icio.us
Engadget
Feedster
Gizmodo
I4U News
Mindjack Daily Relay
Nanodot
Slashdot
Smart Mobs
Techdirt
Technorati


People

Paul Boutin
Dan Gillmor
Lawrence Lessig
Jenny Levine
Karlin Lillington
John Robb
Dolores Tam
Jon Udell
Dave Winer


Drop me a note via Radio
Click here to send an email to the editor of this weblog.

E-mail me directly at
pique@noos.fr

Subscribe to this weblog
Subscribe to "Roland Piquepaille's Technology Trends" in Radio UserLand.

XML Version of this page
Click to see the XML version of this web page.