Epithelial Biology Laboratory

Previous and current research
We use Drosophila as a model organism to investigate both normal tissue development and tumour formation. We focus on the epithelial tissues of the fly, particularly on the developing wing and eye. We are interested in two major questions:

• What determines the architecture of an epithelium?
• How is the growth of an epithelial tissue controlled?

In a genetic screen in the developing eye, we identified a number of mutations that disturb the architecture of this epithelium. One of these mutations inactivates a new Drosophila tumour suppressor gene, called vps25, which encodes a key regulator of endocytosis. Mutation of vps25 causes epithelial cells to lose their apical-basal polarity and over proliferate to form large metastatic tumours. We are interested in understanding the role of endocytosis in epithelial polarity and how loss of epithelial polarity promotes proliferation and metastasis. We are also examining other epithelial morphology mutants identified in this screen.

We also have a long-standing interest in how tissues determine their size. Several important signalling pathways that control size in Drosophila have been identified, including secreted morphogens (such as Wnt/Wingless and TGF-β/Decapentaplegic) and hormonal signals (such as Insulins). Genetic screens in Drosophila recently uncovered several new players, such as the Hippo signalling pathway and a microRNA called bantam. In collaboration with Nic Tapon's lab, we are interested in how these different pathways interact to control the growth of Drosophila tissues.

Future projects
We are conducting an in vivo genome-wide RNAi screen in the Drosophila wing to identify key molecules regulating tissue growth and epithelial morphology. We will combine genetics with cell biology to explore how these molecules act within systems that determine organ size and epithelial architecture.