All bodies depends on stem cells to replenish stocks of highly differentiated but short-lived cells. These include blood, skin, sperm and intestinal epithelial cells. In order to retain the necessary amount of stem cells, the cells themselves have to strike a balance: often, when they divide, one cell remains a stem cell while the other differentiates into something else. If too many stem cells are created, tumors may form, while not enough stem cells can reduce the capacity of tissues to regenerate. Our lab seeks to understand how cells maintain this balance through four avenues of research.
One such avenue is the mechanism of asymmetric germline stem cell (or GSC) divisions. These cells — which we obtain from male Drosophila fruit flies — are an ideal model system to study stem cell behavior. GSCs are attached to somatic hub cells, which maintain stem cell identity.
Another area of focus is the stem cell-specific regulation of centrosomes. Many stem cells, including Drosophila male GSCs, utilize unique regulation of centrosomes to divide asymmetrically. Our lab is interested in identifying and characterizing stem cell-specific centrosomal components, and their potential roles in asymmetric stem cell division.
The lab also recently discovered that sister chromatids of X and Y chromosomes are distinguished and separated non-randomly during GSC divisions. We are currently interested in understanding the molecular and cellular mechanisms of non-random sister chromatid segregation, and its biological significance.
Finally, our lab studies how two stem cell populations coordinate to maintain tissue homeostasis. Many tissues contain multiple stem cell lineages, so in order to maintain a proper balance of cells in the tissue, these populations must coordinate. How exactly they do this, though, is poorly understood. We are interested in the mechanisms that allow different stem cell populations to communicate.
An emerging area of interest for the lab is the function of satellite DNA. Despite its ubiquity and abundance, it has been regarded as genomic junk. The lab’s recent discovery led to a proposal that satellite DNA plays a critical role in packaging the full complement of chromosomes into a single nucleus, a universal feature of eukaryotic cells.