bbrewer

I have been in love with DNA for as long as I can remember. I chose to study replication because it is central to the biological role of DNA as the molecule of inheritance. One of the most striking features of replication in eukaryotic cells is the precision with which each and every chromosomal DNA molecule is replicated exactly once per cell cycle. As a graduate student I demonstrated that this control is also exerted on the naturally occurring, multiple-copy 2-micron plasmid in the yeast Saccharomyces cerevisiae. My current work has shifted to yeast chromosomes and their origins of replication--the sites in DNA where replication begins.

Research is conducted in collaboration with Research Assistant Professor M. K. Raghuraman (Raghu). We are studying the regulation of replication that ensures that each chromosome is duplicated in a timely and precise way. Although the chromosomes of S. cerevisiae (average size, 800 kb) are orders of magnitude smaller than those of plants and animals, they are organized for replication in much the same way: replication occurs from multiple, closely-spaced origins and different parts of a chromosome are replicated at different times during the S phase of the cell cycle. Early on, we developed 2-dimensional gel electrophoresis techniques that allow us to map specific replication origins and to determine the efficiency with which they are activated. More recently, we have developed methods and algorithms to study replication on a genome wide scale using microarrays. The combination of these techniques, along with the tractability of the yeast genome, has allowed us to pose important questions about DNA replication in eukaryotes.