The main focus of our lab is on epithelial morphogenesis:  how do cells coordinate with their neighbors in a tissue to undergo precise reorganization and achieve the correct three-dimensional form?  Secondly, how does the accomplishment of this embryonic ‘origami’ compare between species?  We take a broad approach that addresses the topic at several levels of biological organization, from understanding the molecular regulation of the various processes to examining specific cell shape changes and analyzing properties of whole tissues. 

 Methodologically, our work involves a reverse genetics functional approach (primarily via RNA interference), and the subsequent phenotypic characterizations involve various types of microscopy and image analysis on stained preparations (in situ hybridization and immunohistochemistry) as well as time-lapse movie analyses (including with transgenic lines for fluorescent fusion proteins).  Although this work is focused on developmental genetics, both evolutionary biology and biomechanics are important as related fields.

 We examine the extraembryonic (EE) membranes of insect embryos, using the milkweed bug (Oncopeltus fasciatus) and the red flour beetle (Tribolium castaneum) as our research species.  The EE membranes are an ideal study system as they perform a large variety of morphogenetic behaviors that are common to all animal development, with parallels in such processes as wound healing and vertebrate neural tube closure.  Secondly, they develop superficially to cover the embryo and are thus accessible for live imaging on convenient time scales.  Moreover, these membranes are a defining feature of the insects and have been linked to their spectacular evolutionary success.  On the other hand, when EE development fails, it is often fatal for the embryo.  Despite the importance of the insect EE membranes, there is still much that we do not know about their development, in part due to the very reduced, secondarily derived nature of the extraembryonic tissue in Drosophila.

 The PhD project will examine how the two EE membranes first form in early development, comparing the situations in the beetle and the bug.  A number of candidate genes are currently available for investigation, arising from previous work in the lab and in the published literature, as well as novel candidates arising from a recently completed unbiased screen. 

Ultimately, the aims of this research are: (1) to distinguish specific features from commonalities in animal epithelial morphogenesis via the interspecific comparisons, and (2) to gain a better understanding of the development of the extraembryonic membranes across the insects.