Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Discovering what genes do the high-throughput way

01.10.2003

Researchers at the Howard Hughes Medical Institute in Boston have developed a fast and systematic method that could make it easier to understand how cells from complex animals work. Their results, published this week in Journal of Biology, should inspire scientists to perform comprehensive screens of the fruit fly genome to find molecules that control a variety of cellular processes.

The research team, led by Norbert Perrimon, systematically inhibited the function of around 1,000 Drosophila genes that are predicted to affect diverse cellular processes. They observed that 16% of the inhibited genes altered the form or structure of the cells in some way.

Genes that caused the same changes in the cells when inhibited are likely to work together in a complex or pathway. Clustering genes by their effects allowed the researchers to assign functions to about 50 previously uncharacterised genes. Author Buzz Baum says, "The most exciting thing for me is that now you can take a step back and look at the bigger picture. You can find out which genes act together to do something, so you begin to build up a system-wide understanding of how cells work. Genes work in a community to do something, not on their own. With big-scale experiments you can start to see the internal logic of the cell."

The screening method makes use of RNA interference (RNAi) - introducing double stranded RNA into cells, to interfere with the expression of specific genes. In order to scale up the procedure, which normally tests one gene at a time, the researchers plated out cells into 384-well dishes and then added double stranded RNA to each well. After three days, when the targeted gene should be inhibited, they stained the cells so that they could visualise both DNA and components of the cytoskeleton. They then photographed the cells using an automated microscope.

Two postdoctoral researchers, Baum and Amy Kiger, independently studied the thousands of photographs generated by the screen to characterize the effects of the RNAi treatment on the cells. They created a formal set of criteria to judge the cells consisting of seven classes of change that could have been induced. These included changes to cell number, shape, size and viability. Any changes were only considered significant if both scientists recorded them in replica experiments.

The researchers were also keen to find out if their method could be used to screen for genes that worked in, or inhibited specific molecular pathways. Screens in whole flies for genes that modify the effect of a particular genetic mutation have proved powerful, though time consuming. By adding two sets of double stranded RNA to each well, one that targeted the tumor suppressor gene pten and the other the gene to be tested, the researchers found that they were able to identify genes that modified the effects of inhibiting pten in cells. "These results demonstrate that modifier screens, as previously done in vivo, can be extended to RNAi screening methodology in cell culture", write the researchers.

Drug companies are becoming interested in this technique, as the rate-limiting step in cell-based drug discovery is finding out which protein is inhibited by a particular drug. Using Perrimon’s method they can screen to see which gene, when inhibited, changes the cell in the same way as adding the drug.

"RNAi screens can complement classical Drosophila genetics to assign functions to both known and novel genes," write the researchers. "The same technology can be easily adapted to a wide variety of cell-based studies and a greater genomic scale."

Baum says, "The major difference between this and whole fly screens is that here we can be systematic. We can choose to look at any cell biological process and systematically test the set of genes that could be involved. In the future we will be able to screen the full genome in a few weeks, and look at any cell biological phenomenon."

This press release is based on the following article:

A functional genomic analysis of cell morphology using RNA interference
A A Kiger, B Baum, S Jones, M R Jones, A Coulson, C Echeverri, N Perrimon
Journal of Biology 2:27
http://jbiol.com/content/2/3/27
Published 1 October 2003

Gemma Bradley | BioMed Central
Further information:
http://jbiol.com/content/2/3/27
http://www.biomedcentral.com),

More articles from Life Sciences:

nachricht New application for acoustics helps estimate marine life populations
16.01.2018 | University of California - San Diego

nachricht Unexpected environmental source of methane discovered
16.01.2018 | University of Washington Health Sciences/UW Medicine

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

White graphene makes ceramics multifunctional

16.01.2018 | Materials Sciences

Breaking bad metals with neutrons

16.01.2018 | Materials Sciences

ISFH-CalTeC is “designated test centre” for the confirmation of solar cell world records

16.01.2018 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>