A new method furthers understanding of evolutionary genetics

February 10, 2016
A depiction of the double helical structure of DNA. Its four coding units (A, T, C, G) are color-coded in pink, orange, purple and yellow. Credit: NHGRI

Since Darwin, evolutionary biologists have been fascinated by how different organisms are from one another. The ultimate goal is to understand how mutations in DNA, the genetic blueprint, shape the growth and behavior of animals, plants, and microbes around us. Standard research tools have been available for some time to study the genetics of closely related individuals—for example, the variation of lactose intolerance between humans. But understanding differences between long-separated species has remained a challenge. Publishing online in Nature, Buck Institute professor Rachel Brem and her colleagues have broken through this roadblock by focusing on distantly-related species of yeast, the single-celled organism used to make beer, wine and bread.

"Yeast is an easy system to work with and a good model for more complicated organisms," said Brem. "It was a great platform for us to develop a method for discovering what makes unique."

The researchers first noted that some species of yeast were much better than others at deriving energy from galactose, a sugar found in plant materials. Brem and her collaborators then identified seven locations in the yeast DNA at which the species had distinct genetic information, at sites that regulated how galactose metabolism genes turned on and off as the cells grew. Ultimately, the researchers showed that these regulatory changes were the reason why used galactose differently.

"What our work shows is that research in genetics is no longer limited to surveys of close relatives," said Brem. "So we can start to understand how species of malaria parasites acquired different infectious behaviors over time, and develop new species-specific treatments. And we can figure out how short-and long-grained rice developed their respective shapes in the ancient past, and make new rice varieties. We are excited about future work far beyond ."

The work could have implications for research on aging, said Buck professor Gordon Lithgow. His lab studies tiny nematode worms in order to uncover genes and small molecules that prolong lifespan. As an example, Lithgow sites the Caenorhabditis family of nematodes which contains widely divergent species, some of which have significant differences in lifespan. "These animals have incredibly different genomes, even though they look identical under the microscope," he said. "Tools like this give us an opportunity to compare their DNA - what are the genes that account for their lifespan changes? It's the first step in understanding how we might exploit those differences in order to extend healthspan."

Explore further: Scientists rise to the challenge of identifying and comparing yeast genomes

More information: Jeremy I. Roop et al. Polygenic evolution of a sugar specialization trade-off in yeast, Nature (2016). DOI: 10.1038/nature16938

Related Stories

Study shows brewer's yeast hybridizes in wasp gut

January 19, 2016

(Phys.org)—A team of researchers from Italy, Uruguay and Spain has found via lab study that common brewer's yeast not only mate in the guts of wasps, but interbreed with other yeast species, producing hybrids. In their ...

Gene crowding affects cell development

January 12, 2016

The crowding of genes inside the nucleus of a cell affects the way they replicate, and how they are turned on and off, according to a study led by the Liggins Institute at the University of Auckland.

Recommended for you

New analysis of big data sheds light on cell functions

October 26, 2016

Researchers have developed a new way of obtaining useful information from big data in biology to better understand—and predict—what goes on inside a cell. Using genome-scale models, researchers were able to integrate ...

Study shows how giraffe assassin bugs outwit spider prey

October 26, 2016

(Phys.org)—A biologist at Macquarie University in Australia has discovered the secret behind the giraffe assassin's ability to catch and kill spiders in their webs. In his paper published on the open access site Royal Society ...

Researchers identify genes for 'Help me!' aromas from corn

October 25, 2016

When corn seedlings are nibbled by caterpillars, they defend themselves by releasing scent compounds that attract parasitic wasps whose larvae consume the caterpillar—but not all corn varieties are equally effective at ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.