Chromosome fragility at tRNA genes in Baker’s Yeast

by John Mann
Faculty advisor: Dr. Brian Lenzmeier

Chromosome breakage is associated with many types of cancer.  Cancer cells often have a chromosome that has broken and not been repaired correctly.  Little is known about why the chromosome broke in the first place.  In many cases of leukemia, the chromosome tends to break at very specific DNA sequences.  Previous research by BVU students has identified tRNA genes as preferential sites of chromosome breakage in yeast.  We are interested in uncovering experimental conditions that alter chromosome breakage rates in general as well as specifically at tRNA genes.  We have used a genetic assay that allows us to detect chromosome breakage events based on growth on different types of agar plates.  We determined the chromosome breakage rates under several environmental conditions and have uncovered circumstances that lead to an increase in chromosome breakage.