Yeast study charts survival impact of genetic mutations

Scientists from the MRC Human Genetics Unit have mapped how thousands of genetic mutations can affect a cell’s chances of survival: April 2016

Scientists from the MRC Human Genetics Unit have mapped how thousands of genetic mutations can affect a cell’s chances of survival.

The study reveals how different combinations of mutations in a single gene can influence whether the cell lives or dies. It is the first time scientists have been able to measure the effects of every possible combination of mutations in a gene.

The technique used could aid studies into the effects of gene mutations linked to human diseases.

The research group produced 60,000 strains of yeast, each with a different combination of mutations in a single gene. They watched the cells to see what effect the mutations had on survival and whether different combinations of genetic changes helped the yeast to fare better or worse.

In some cases, the effects of different mutations cancelled each other out and the cells survived. The effects of other mutations added together to greatly reduce the cells’ chances of survival.

Genetic changes that have the greatest combined effect on survival tend to be located close to each other in the three-dimensional structure of the genetic material. This means that the technique could help scientists to predict the shapes of molecules encoded in our genes.  

“We pitted 60,000 mutated yeast strains against each other in a fight for survival. Those that survived were able to produce more copies of themselves and dominate the population. This is evolution in action. Cells without any mutations fared the best and reproduced faster than any of the mutated strains, which tells us that this particular gene has been optimally configured by evolution.”

The research, published in the journal Science,received funding from the Medical Research Council (MRC) and the Wellcome Trust.