My collaborators include: Jordan Hoffmann and Chris Rycroft at the Harvard John A. Paulson School of Engineering and Applied Sciences, Steve DiNardo at the University of Pennsylvania School of Medicine, James Crall at the Harvard University Center for the Environment, and members of the Extavour Lab.
High-throughput live-imaging of embryogenesis
Recent advances in microscopy have made it possible to capture morphogenesis in 3D time-lapses with excellent temporal and spatial resolution. The datasets that result are quite useful, but they are time- and labor-intensive to generate. We show that for some experimental systems a complementary approach is also helpful, namely high-throughput epifluorescence. It is technically simple, and it allows the user to retain a comparable x-y and temporal resolution, while trading off excellent z-resolution for a 10- to 100-fold increase in sample size.
The hour-long webinar covers several ways that biologists can add automation to their microscopy-based research. The video recording of the webinar is available for free, but viewers need to register to get access:
While developing techniques for time-lapse imaging, I also had the opportunity to beta-test the Zeiss Celldiscoverer 7, a microscope that was designed specifically for high-throughput live-imaging. I worked with Sebastian Gliem at Zeiss, and we co-wrote an article for the industry magazine Imaging and Microscopy:
Modular, customizable molds for mounting samples
Live-imaging embryos in a high-throughput manner is essential for shedding light on a wide range of questions in developmental biology, but it is difficult and costly to mount and image embryos in consistent conditions. We are developing tools to make it easier for biologists to design and build their own custom mounting devices.
A forthcoming journal article will describe these devices in detail, but in the mean time please don’t hesitate to contact me for more information about the designs or protocols (donoughe [at] harvard.edu). A pre-print is available on bioRxiv:
Photo credits: beta-testers Andrew Gehrke and Mara Laslo
Embryonic development of the cricket Gryllus bimaculatus
SUMMARY: The two-spotted field cricket, Gryllus bimaculatus is an increasingly popular model species. It is a member of the order Orthoptera, a group that branches basally with respect to the clade that includes flies, beetles, bees, and butterflies. We used a combination of brightfield timelapse microscopy, confocal microscopy, 3D reconstructions, and measurements of egg dimensions to comprehensively describe the morphogenesis and anatomy of the cricket embryo. This resource will facilitate further studies on G. bimaculatus development and serve as a useful point of reference for other studies of wild-type and experimentally manipulated insect development.
NOTE: On the Resources page of this website, I have included additional materials for anyone interested in cricket embryonic development.
The role of BMP signaling in cricket germ cell specification
SUMMARY: Primordial germ cells are the cells that turn into sperm or egg. Thus, they are the only lineage of cells in a body that give rise to the next generation. For the first time, we uncovered the molecular basis of germ cell formation in an insect other than fruit fly, discovering that the process is strikingly similar to that of mice.
Planar polarity in the epidermis of Drosophila melanogaster
SUMMARY: In order to function properly, cells often need to “know” things beyond the information encoded in their genome. One thing a cell needs to know is how it is oriented with respect to the arrangement of the other cells in its tissue; this is called cell polarity. In this project we used the epidermis of the fruit fly to ask how different genes contribute to cell polarity. To our surprise, we discovered that two groups of genes separately imbue cells with the same sort of cell polarity, but each group has a particular subset of cells where its effect is strongest.
The biomechanics of dragonfly and damselfly wing flexibility
SUMMARY: How could a dragonfly change the shape of its wings during flight even though it has no muscles within the wings? We used mechanical tests and detailed micrographs of 12 species to show that tiny flexible protein pads and mechanical linkages are built into the surface of wings. These microscopic structures affect how a wing changes shape in response to aerodynamic forces.