Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New thoughts on evolution arise from UH yeast study

29.11.2002


Novel Method of Creating New Species Observed in Laboratory Yeast



The sex life of yeast has University of Houston biologists fermenting new ideas about evolution and beer.

Researchers studying yeast reproductive habits have for the first time observed a rapid method for the creation of new species, shedding light on the way organisms evolve and suggesting possible ways to improve yeast biotechnology and fermentation processes used in beer and wine-making.


“Most models of speciation require gradual change over a very long period of time, and geographic or ecological isolation for a new species to arise,” says University of Houston biologist Michael Travisano. “Our study suggests that mating two separate species to produce hybrids can result in a new species readily and relatively quickly, at least in yeast, but possibly in other organisms as well.”

Travisano, an assistant professor in the UH Department of Biology and Biochemistry, says the findings extend the range of known mechanisms that cause reproductive isolation. The study appears in the Nov. 29 issue of the journal Science.

Duncan Greig, a postdoctoral researcher in Travisano’s lab, conducted experiments that put two different species of yeast together, Saccharomyces cerevisiae and Saccharomyces paradoxus. One way that yeast, a one-celled organism, can replicate is by producing spores. When spores from these two species joined, they produced hybrid offspring, similar to crossing a female horse with a male donkey and getting a mule.

Unlike mules, which are sterile, a few of the yeast hybrids were fertile. Those hybrids produced viable offspring when they were allowed to “autofertilize,” which means an individual’s spores fertilized themselves to produce an offspring without involving another yeast cell.

However, the hybrids did not produce viable offspring when mated back to their parent species.
“Other labs have generated hybrids such as these before, but we went a step further and crossed the fertile ones back with their parents,” Travisano says. While there are various definitions of a species, Travisano says individuals that are fertile with themselves and isolated from their parents certainly qualify as a new species. He estimates the experiment took about a month to generate the new yeast species.

Understanding why some hybrids are fertile and others are not is a key question, according to Greig and Travisano, and may have implications for the evolution of species besides yeast.

“What are the genetic or molecular mechanisms that make some hybrids sterile and others fertile and able to propagate as a new species? While our work was done with yeast, presumably the interactions that prevent or encourage speciation occur in other organisms as well,” Travisano says.

The method by which the hybrids replicated and formed a new species is called homoploid hybrid speciation, in which the new hybrid species contain the same total amount of genetic material as the parental species. It is not found in any animal species and only very rarely among plants, Travisano says.

“We think it may be happening in nature, but this is the first time this mode of speciation has been observed in a microorganism such as yeast,” he says. “In terms of how we typically think of speciation, this method is pretty rare, which makes it kind of a surprise how easy it was to get it to work.” This method is in contrast with polyploid hybrid speciation, which occurs readily in plants and involves an increase of two or more times the genetic material in the new hybrid species than in the parental species, Travisano says.

He adds that the yeast’s ability to speciate so quickly in the lab is due in part to its ability to autofertilize.
“Autofertilization is thought to be relatively common in wild yeast, but the natural history of yeast is not very well understood,” he says.

One application of the research may be to benefit industries that utilize yeast in fermentation.

“If we put these hybrid individuals in various environments, we’d like to see whether they do better in some environments than their parental species,” Travisano says. For example, one parent species thrives in cold temperatures and the other parent does well in the heat – what kind of environment might the hybrid prefer?
“Presumably you might be able to optimize wine or beer-making by genetically engineering a yeast species specific to your needs,” Travisano says. “If you’re interested in yeast biotechnology, studies such as this could tell you something about the nature of your yeast and how to engineer it.”

Travisano’s and Greig’s research was funded by the Wellcome Trust and was done in collaboration with Edward J. Louis and Rhona H. Borts at the University of Leicester.


Amanda Siegfried | EurekAlert!
Further information:
http://www.uh.edu/admin/media/sciencelist.html

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

Metallic nanoparticles will help to determine the percentage of volatile compounds

20.10.2017 | Materials Sciences

Shallow soils promote savannas in South America

20.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>