Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Visualizing Gene Activity May Provide Insight Into Development

09.08.2004


A technique developed by University of California, San Diego biologists, which uses bright fluorescent dyes to reveal the activity of genes in individual cells of an organism, promises to be a boon to developmental biologists, and may provide new insight into how cancerous tumors begin and grow.



The advance, described in the August 6 issue of Science, allows researchers, for the first time, to simultaneously visualize the activity of multiple genes in the same cell. The combination of genes that are active in a particular cell during development determines that cell’s fate—what type of cell it becomes. The advance also makes it possible to quantify how active a gene is, and even infer the genetic makeup of an organism.

“In addition to facilitating our own research on fruit fly development, there are many potential applications for this technique,” says Ethan Bier, a professor of biology at UCSD who led the research team. “For example, it could be used to understand how tumors arise and grow, by revealing what genes are turned on and when. With this information, it should be possible for cancer biologists to predict how aggressive a tumor will be from its early patterns of gene expression.”


“Cell fate decisions must be understood in order for any of the incredible medical potential of stem cell therapy to be realized,” adds Dave Kosman, a research scientist in the Bier and McGinnis laboratories and lead author on the paper

Multiplex labeling, as the technique is called, uses RNA tagged with a fluorescent molecule to signal that a gene is turned on. When a gene is “on” it produces RNA copies—gene transcripts—of itself. The biologists designed fluorescently-tagged RNA molecules that are complementary to the gene transcripts, and bind to them like Velcro. Therefore a fluorescent beacon reveals the existence and location of the RNA gene copy.

“Multiplex labeling has allowed us to directly map the activation patterns of micro-RNA genes, which were hitherto undetectable,” says William McGinnis, a professor of biology at UCSD and co-principal investigator of the study. “Micro-RNAs were known to be important in development, but this is the first evidence indicating that these genes can control the embryonic body plan.”

Different colored fluorescent molecules can be used to identify transcripts from different genes in the same cell. It works even if one gene is much more active than another, because the amount of fluorescence of each color is quantified separately.

“When using the microscope to measure the fluorescence, the light is fanned out into a rainbow, and each color is read through a separate channel,” explains Bier. “That way if the light is 90 percent blue and ten percent yellow, it might look blue to the naked eye, but the microscope detects each color present.”

According to Bier, multiplex labeling fills a gap in developmental biologists’ toolkit between gene chips, which can identify several hundred gene transcripts at a time, but not their location, and methods that can reveal the identity and location of up to three gene transcripts simultaneously—though not if they are in the same cell. So far the researchers have used multiplex labeling to visualize the activity of up to seven genes at the same time, but they predict it will be possible to increase this to 50.

Newly developed, ultra-bright fluorescent molecules make the multiplex labeling technique possible. The fluorescent molecules were provided by Molecular Probes, Inc., and the company’s scientists also shared their expertise with the UCSD researchers. Developing an effective way to attach the fluorescent molecule to the RNAs complementary to the gene transcripts, and perfecting the overall labeling process were also pivotal in the development of the technique.

“Up until now visualizing gene transcripts has been more art than science,” says Kosman. “There was a lot of trial and error involved. We have developed a reliable technique that is powerful enough to generate a molecular fingerprint of the gene activity in a single cell.”

Bier contrasted the level of detail revealed with multiplex labeling and previous techniques for visualizing gene activity as being akin to “the difference between looking at the stars through a telescope versus binoculars.” The researchers point out that while they have refined the technique in Drosophila embryos, it will likely require modifications to work in other organisms. A detailed guide to the labeling process accompanying the paper, and available through Science’s website, should facilitate the necessary adaptations.

Other UCSD contributors to the paper were Claudia M. Mizutani and Derek Lemons and W. Gregory Cox was a contributor from Molecular Probes, Inc. This research was supported by grants from the National Science Foundation and the National Institutes of Health.

| newswise
Further information:
http://www.ucsd.edu

More articles from Life Sciences:

nachricht Staying in Shape
16.08.2018 | Max-Planck-Institut für molekulare Zellbiologie und Genetik

nachricht Chips, light and coding moves the front line in beating bacteria
16.08.2018 | Okinawa Institute of Science and Technology (OIST) Graduate University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Staying in Shape

16.08.2018 | Life Sciences

Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter

16.08.2018 | Earth Sciences

Protein droplets keep neurons at the ready and immune system in balance

16.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>