May 23, 2015
Researchers create human-yeast hybrid to study genetics
Biologists at the University of Texas at Austin have developed a new type of yeast that is part fungus and part human, demonstrating that two types of lifeforms separated by over a billion years of evolution still have hundreds of genes in common.According to Discovery News, those genes are remnants of the last common ancestor between people and fungi – DNA which is virtually unchanged and remained surprising stable during the course of evolution. By creating partially-human yeast, the team may have found a way to better understand genetic disorders and to evaluate potential new treatments for these conditions.
“Cells use a common set of parts and those parts, even after a billion years of independent evolution, are swappable,” said Edward Marcotte, a professor in the UT-Austin Department of Molecular Biosciences and co-director of the Center for Systems and Synthetic Biology. “It's a beautiful demonstration of the common heritage of all living things.”
Altered yeast could be used to evaluate new drugs
Yeast possesses about 450 genes that are essential for their survival, and Marcotte’s team replaced the fungal version of some of these genes with the human equivalent. They created hundreds of new strains of yeast each year, each with one human gene, and nearly half of those engineered strains were able to survive and reproduce after the DNA swap.
This type of experiment isn’t new, but this is the first large-scale study to swap hundreds of gene pairs. The large amount of tests allowed the researchers to determine what made DNA replaceable, and they found that the genetic similarity was not the most important factor. Rather, the modules (groups of genes which work as a unit to accomplish a task) that they were a part of was the key factor.
“This work is basically showing that you can take a fuel injector from a tractor and swap it for a fuel injector in your Toyota and it will still work, more or less, because they're both fuel injectors,” Marcotte explained. He added that they have already identified 200 genes that can be swapped, and that there may be another 1,000 or so that could be interchangeable.
The authors believe that their findings could be useful in the search for drugs to treat a variety of different human genetic disorders, and that future studies could compare different strains of these humanized yeast to discover more about how mutations can impact a person’s health. The researchers also believe the modified yeast could test new medicinal therapies.