Research Overview
We use the fruit fly, Drosophila melanogaster, as a model system for studying how the cell cycle is regulated and modified in development. Our work focuses on two major subjects:

Role of the SCF-Skp2 ubiquitin ligase in maintaining genome stability 
The entry into S-phase is the most carefully regulated decision made by the cell, and a large number of the known oncogenes and tumour suppressors act at this point. The SCF complex plays a critical role in S-phase regulation, functioning both as a tumour suppressor and as an oncogene in different contexts. We have focused on the less understood tumour suppressive roles of SCF-Skp2. We found that loss of Skp2 or an interacting protein, Cks85A results in inappropriate DNA replication and consequent genome instability in Drosophila. To determine how these proteins maintain genome stability, we are characterizing interacting proteins and ubiquitinated targets of the SCF-Skp2, employing a combined biochemical and genetic approach. 

Spatial and temporal control of cell cycle transitions in meiosis and embryogenesis
Meiosis is the most complex and carefully regulated of all cell divisions. The cell divisions of the early embryo, in contrast, represent an extremely simplified, somewhat unregulated cell cycle, consisting of only S-phase and mitosis. Though meiosis and embryonic mitosis are very different from each other, these two cell division programs occur within minutes of each other in a common cytoplasm, utilizing a common pool of cell cycle regulators that are deposited into the egg during oogenesis. These unique constraints mean that cell cycle regulators must be under very sophisticated temporal and spatial control. We are using a combination of approaches to examine how female meiosis and the early embryonic divisions are regulated.