Yeast provides a genetic map to understanding trait inheritance and complex diseases such as cancer

Researchers in the Human Biology Division have harnessed the power of yeast to study trait inheritance and the genetics of complex characteristics at the most basic, molecular level.

Complex traits result from the interplay of multiple genes. Complex conditions, which include diseases like diabetes and cancer and behaviors such as violence or aggression, have been difficult to study in humans and other mammals, the systems in which most analyses have been conducted.

Yeast-the single-celled organism used to brew beer and bake bread-provides a powerful new avenue for studying natural variation that results from complex genetic interactions. But the researchers caution that even in the case of this simple fungus, the study of complex traits is likely to remain a formidable challenge in biology.

Drs. Rachel Brem and Gael Yvert, postdoctoral fellows in Dr. Leonid Kruglyak's lab, led the research that resulted in a new system to study the architecture of complex traits.

"The good news is that our method worked and that we can use it as a way to study complex traits," Yvert said. "We can expand it to the study of other organisms. The caution is that we're still dealing with a complex system that is likely to be even more so in humans."

The finding by Brem and Yvert allows researchers for the first time to regard yeast as a viable model for understanding complex genetic traits and diseases in higher organisms, including humans.

"Until now, people hadn't really used yeast much to study complex traits," Kruglyak said. "This provides a road map for understanding what genetic complexity really looks like at the molecular level."