Honours supervisors and projects

Dr Coral Warr

Drosophila Cellular and Developmental Genetics

Telephone: 9905 5504
Email: coral.warr@sci.monash.edu.au

All projects in Coral's lab involve a range of widely applicable molecular biology and genetic techniques such as: PCR, cloning, RNA in situ hybridisation, immunohistochemistry, reporter genes, cell culture work, RNA interference, Drosophila breeding experiments, production of transgenic Drosophila.

Project 1. Odorant Receptors and Olfactory Signalling in Drosophila

Olfaction is a fascinating sense as animals can detect and discriminate amongst literally thousands of different chemical compounds. How can this be achieved at the molecular level? How does such a complex information coding system work? As well as this fundamental interest, there are also applied aspects to this research in pest control and in the development of biosensors, machines that can sense volatile chemicals in the environment.

We are studying the molecular basis of odour detection in Drosophila melanogaster, which offers many advantages such as a sequenced genome, powerful genetic approaches to study gene function, and well developed electrophysiological and behavioural assays to measure olfactory function. In insects odorants are initially detected in olfactory receptor neurons by a large family of odorant receptor proteins (Ors), however how these receptors function to bind odorants and to activate downstream signal transduction pathway(s) is not well understood. Two possible olfaction projects aimed at addressing these questions are described below, these will be finalised later and tailored to student interests.

(i) Identification of olfactory genes

Our lab has identified a mutant strain of Drosophila that lacks olfactory responses. This project involves using a number of approaches to identify the gene that is affected in this mutant, this gene may be involved in olfactory signalling or in olfactory system development.

(ii) Structure/function analysis of Drosophila Odorant Receptors

(co-supervised by Marien de Bruyne) - Twelve Drosophila species genome sequences have now been completed, providing a wealth of information for comparative genomics. We aim to identify functionally important regions in Ors by analysing the relationship between Or sequence changes and ORN response changes. This involves cloning and expressing orthologous and artificially synthesized receptors in D. melanogaster and in cell culture systems. This project may also involve phenotypic studies using behaviour and/or electrophysiological assays depending on the interests of the student.

Project 2. MACPF (Membrane Attack Complex/Perforin-like) gene function in Drosophila development

Co-supervised by Professor James Whisstock, Department of Biochemistry & Molecular Biology

The Drosophila torso-like gene (tsl) is the only fly member of the Membrane Attack Complex / Perforin-like (MACPF) protein superfamily, which includes pore forming toxins that play key roles in vertebrate immunity by forming pores in membranes and lysing cells. However some MACPF proteins, such as Tsl, play a role outside immunity and appear to be essential for developmental processes. The tsl gene is essential for correct terminal patterning in the Drosophila embryo. It is maternally expressed and secreted by a subpopulation of follicle cells at the anterior and posterior regions of the maturing oocyte, where it is proposed to function to permit proteolytic cleavage of the ligand for the Torso receptor tyrosine kinase, ensuring Torso signalling only in these regions and, in consequence, the development of appropriate anterior and posterior structures. However, the mechanism of action of Tsl in this process is not known. Tsl also has other roles in Drosophila, as we have shown that it is expressed in the embryo in a number of tissues including the central nervous system and the salivary glands.

Several possible projects are possible aimed at characterising the functions of Tsl in Drosophila development. Students will be based in Coral's lab but may undertake some experiments in the Whisstock lab, depending on their interests.

* Recent Honours students working in Coral's lab have gained employment as follows: AiLeen Chan, Research Assistant, Diagnostics, MacFarlane Burnet Institute; Takahiro Honda, PhD student, Drosophila neurogenetics, Monash University; Amy Nelson, Research Assistant, Cytogenetics, Monash Medical Centre, Bree Buszard, PhD student, Cell signalling in Drosophila, Monash University.