Marin Science Seminar Presentation: “X-rays Don't Really Give you Superpowers: How Cells Fix DNA Breaks” Getting a tan?  Having a smoke?  Getting an X-ray?  To varying degrees, all of these things cause damage to your DNA.  Moreover, your DNA is unavoidably damaged all of the time as a consequence of normally physiology.  Fortunately, humans have evolved many mechanisms to repair this DNA damage.  But, before a cell can repair DNA damage, such as a broken chromosome, it has to know that the chromosome has been broken in the first place.  How do cells do this?  Download the flyer here.
            Our laboratory studies a pathway that identifies DNA breaks in cells.  This allows the cells to do two things:  Fix the breaks and stop dividing (block mitosis) so that the damaged cells do not pass on the broken chromosome to its daughters.  This job is so fundamental to life that the genes that perform it arose about a billion years ago.  Because of this, humans and simple organisms, like yeast, share many of the same genes, performing many of the same functions. Because it is difficult to do these experiments in humans (volunteers??), we do them in yeast. (February 9, 2011)

Dr. Toczyski is a Professor of Biochemistry and Biophysics and the Director of the Cell Cycle Regulation Program at the University of California, San Francisco.