Eric Vitriol

In an effort to study cellular response to a specific type of DNA damage, we have designed a system for inducing double stranded DNA breaks in the budding yeast, S. cerevisiae. This system involves in vivo production of a DNA cleaving enzyme (an endonuclease) under the GAL1 promoter; the endonucleases can be turned on or off in response to the type of carbon source given to the cell. This system provides a unique opportunity to observe both the effect of DNA damage during the cell cycle (in particular during chromosome segregation) and how the cell manages to repair the double stranded DNA breaks. Lack of repair of these DNA breaks can lead to abnormal growth or cell death. Repair of double stranded DNA breaks is performed in part through the Rad52 mediated repair pathway. Using fluorescence microscopy, the activity of Rad52 is observed in response to several different endonucleases.