Biologists identify genes that prevent changes in physical traits due to environmental changes

November 4, 2008

New York University biologists have identified genes that prevent physical traits from being affected by environmental changes. The research, which studied the genetic makeup of baker's yeast, appears in the latest issue of the Public Library of Science's journal, PloS Biology.

NYU biologists Mark Siegal, an assistant professor, and Sasha Levy, a post-doctoral fellow, who are part of NYU's Center for Genomics and Systems Biology, conducted the study.

The researchers sought to understand how organisms develop and function reliably, despite experiencing a range of environmental conditions and genetic differences caused by mutations.

"Most species maintain abundant genetic variation and experience a wide range of environmental conditions, yet phenotypic—or physical—differences between individuals are usually small," Siegal explained. "This phenomenon, known as phenotypic robustness, presents an apparent contradiction: if biological systems are so resistant to variation, how do they diverge and adapt through evolutionary time?"

To identify genes that buffer environmental and genetic variation, which may influence how novel traits evolve, the researchers examined Saccharomyces cerevisiae, a species of budding yeast. They investigated the molecular mechanisms that underlie its phenotypic robustness and how these mechanisms can be broken to produce differences in physical appearance within the species.

Siegal and Levy sought to identify genes that contribute to phenotypic robustness in yeast by analyzing the differences in their phenotypes in a comprehensive collection of single-gene knockout strains—that is, they removed these genes to determine if the resulting phenotypes were more variable from cell to cell.

They determined that approximately 5 percent of yeast genes, or approximately 300 genes, break phenotypic robustness when knocked out. These genes tend to interact genetically with a large number of other genes, and their products tend to interact physically with a large number of other gene products. When they are absent, the cellular networks built from their interactions are disrupted and physical differences in the species result. In nature, the researchers hypothesized, some individuals might then have physical features that yield an advantage over the others.

"If so, the loss of phenotypic robustness could actually serve an adaptive role during evolution," Siegal explained.

Source: New York University

Explore further: Species speed up adaptation to beat effects of warmer oceans

Related Stories

How human genes affect the microbiome

October 3, 2016

Our genes determine to some extent which bacteria live in our intestines. Studies on human twins and experimental work with animals have both confirmed that our microbiome is partly hereditary. But so far, there was only ...

Fruit-fly diet impacts descendants, researcher finds

August 16, 2016

For a fruit fly, what its grandparents ate may affect how much it weighs. But the passing down of a body type based on diet is not a simple cause and effect, a University of Alabama researcher has found.

Recommended for you


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.