Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

’Cellular antennae’ on algae give clues to how human cells receive signals

08.05.2006
By studying microscopic hairs called cilia on algae, researchers at UT Southwestern Medical Center have found that an internal structure that helps build cilia is also responsible for a cell’s response to external signals.

Cilia perform many functions on human cells; they propel egg and sperm cells to make fertilization possible, line the nose to pick up odors, and purify the blood, among other tasks.

With such a range of abilities, cilia serve as both motors and "cellular antennae," said Dr. William Snell, a professor of cell biology at UT Southwestern and senior author of new research on cilia published in the May 5 issue of Cell.

Genetic defects in cilia can cause people to develop debilitating kidney disease or to be born with learning disabilities, extra fingers or toes, or the inability to smell.

But no one really knows how cilia work, or, in some parts of the body, what their function is.

"There are cilia all over within our brain, and we don’t have a clue about what they’re doing," Dr. Snell said.

He and his team use the microscopic green alga, Chlamydomonas reinhardtii, which has two individual cilia. This alga allows researchers to manipulate genes and study the resulting effects on cilia in a way that would be impossible in animals such as mice.

"Chlamy is one of the few model organisms in which it’s possible to do these kinds of studies," Dr. Snell said. Normally, cilia — also called flagella — are built and maintained by an internal bidirectional, escalator-like system that ferries molecules to and from the tips by a process called intraflagellar transport, or IFT.

The UT Southwestern researchers used a mutant temperature-sensitive strain of the alga that behaved normally at lower temperatures. At higher temperatures, however, the IFT process stopped, and its components disappeared from the cilia. The cilia themselves were still able to beat, or move back and forth, for about 40 minutes before they began to shorten.

The team focused on fertilization of the alga, a process that requires a cilium to bind to a molecule on a cilium from a cell of the opposite mating type. They found that when the external molecule binds to a cilium, it activates an enzyme that signals the start of a chain of chemical reactions.

Although the cilia could move without IFT and bind to the molecules of the cilia of the opposite type, those cells were unable to respond to the signaling molecules. The failure to activate the chain of chemical reactions indicated that IFT was necessary for this function.

Analysis showed that the cilia signaling process was similar to that found in human cells, such as those in the nose involved in the sense of smell and those in the developing nervous system that sculpt our brains.

Uncovering this series of reactions will make it possible to test, for instance, drugs that can affect cilia, in the hope of finding substances that would also be effective in higher animals, Dr. Snell said.

"This is another example of how basic science research can have big results," he said. "Studies on Chlamydomonas will help us understand the unique qualities of cilia that have led to their use in chemosensory pathways in humans."

Other UT Southwestern researchers involved in the study were Dr. Qian Wang, lead author and postdoctoral researcher in cell biology, and Dr. Junmin Pan, assistant professor of cell biology.

The work was supported by the National Institutes of Health.

Aline McKenzie | EurekAlert!
Further information:
http://www.utsouthwestern.edu

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Researchers invent tiny, light-powered wires to modulate brain's electrical signals

21.02.2018 | Life Sciences

The “Holy Grail” of peptide chemistry: Making peptide active agents available orally

21.02.2018 | Life Sciences

Atomic structure of ultrasound material not what anyone expected

21.02.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>