New research on mutation in yeast can enhance understanding of human diseases

Jun 19, 2008

[B]Work from UNH Hubbard Center, Indiana University, others enhances understanding of genetics in human diseases[/B]
Yeast, a model organism heavily relied upon for studying basic biological processes as they relate to human health, mutates in a distinctly different pattern than other model organisms, a finding that brings researchers closer to understanding the role of evolutionary genetics in human diseases and cancer. The study, by researchers from the University of New Hampshire, Indiana University, Harvard University, and the University of Utah, appears in Proceedings of the National Academy of Science (PNAS) Online Early Edition this week (June 16 – 20, 2008).

"In biology, the mutation is an absolutely fundamental process, essential to evolution but also the source of all genetic disease," says Kelley Thomas, associate professor of biochemistry and director of the Hubbard Center for Genome Studies at the University of New Hampshire. "Despite its importance, we still don't know much about the basic processes of mutation." Cancers are caused by mutations, as are inherited diseases like Huntington's disease and fragile X syndrome, the most common inherited form of mental retardation.

"If we know more about the patterns of mutation, we'd be able to better understand the origins of these diseases – and maybe prevent them," says Thomas.

The researchers asked a fundamental question: "What is the baseline rate and spectrum of mutation in yeast?" They found that, like the previously studied mutations in the nematode Caenorhabditis elegans, the yeast Saccharomyces cerevisiae had a very high rate of mutation from generation to generation.

Its patterns of mutation, however, turned out to be unique. While C. elegans mutations were largely the result of inserting or deleting base pairs of DNA, yeast's patterns of mutation were characterized by changing one base pair for another. "That was really surprising, that we didn't find that adding or subtracting in yeast," says Thomas. He adds that the consequences of inserting and deleting base pairs can be much more dramatic than substituting one base pair for another.

Comparing the mutation rates and spectrums of these two model organisms informs researchers' assumptions about mutation relevant to human health. "We were surprised that there isn't a common spectrum of mutation," says Thomas. "However, it's exciting, because if we can describe patterns of mutation, maybe we can understand why some organisms, including people, are susceptible to certain mutations and not others."

The approach used in this study allows yeast to accumulate mutations in the near absence of natural selection. By doing this, cells with mutations that might otherwise be lost because their cell is outgrown by others can continue to survive and be analyzed for their mutations. With this study, Thomas and his colleagues overcome a major limitation to the study of mutation by using a new generation of sequencing technology that let them sequence the entire genome of each yeast strain and to identify the rare mutational events that have taken place. This way, the yeast accumulate mutations that might otherwise make them "bad yeast" – the weak survive – and look for them across the entire 10 million base pair genome.

"The beer you make with this yeast is horrible," Thomas jokes.

Source: University of New Hampshire

Explore further: Experimental Ebola drug heals all monkeys in study (Update)

add to favorites email to friend print save as pdf

Related Stories

Shell files new plan to drill in Arctic

29 minutes ago

Royal Dutch Shell has submitted a new plan for drilling in the Arctic offshore Alaska, more than one year after halting its program following several embarrassing mishaps.

Aging Africa

41 minutes ago

In the September issue of GSA Today, Paul Bierman of the University of Vermont–Burlington and colleagues present a cosmogenic view of erosion, relief generation, and the age of faulting in southernmost Africa ...

Team pioneers strategy for creating new materials

19 minutes ago

Making something new is never easy. Scientists constantly theorize about new materials, but when the material is manufactured it doesn't always work as expected. To create a new strategy for designing materials, ...

Team defines new biodiversity metric

54 minutes ago

To understand how the repeated climatic shifts over the last 120,000 years may have influenced today's patterns of genetic diversity, a team of researchers led by City College of New York biologist Dr. Ana ...

Mysteries of space dust revealed

59 minutes ago

The first analysis of space dust collected by a special collector onboard NASA's Stardust mission and sent back to Earth for study in 2006 suggests the tiny specks open a door to studying the origins of the ...

NASA animation shows Hurricane Marie winding down

1 hour ago

NOAA's GOES-West satellite keeps a continuous eye on the Eastern Pacific and has been covering Hurricane Marie since birth. NASA's GOES Project uses NOAA data and creates animations and did so to show the end of Hurricane ...

Recommended for you

Ebola in mind, US colleges screen some students

15 hours ago

University students from West Africa may be subject to extra health checks when they arrive to study in the United States as administrators try to insulate their campuses from the worst Ebola outbreak in ...

WHO: More Ebola cases in past week than any other

17 hours ago

The past week has seen the highest increase of Ebola cases since the outbreak in West Africa began, the World Health Organization said Friday, offering more evidence that the crisis is worsening.

User comments : 0