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 New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>