Image: Drosophila female reproductive machinery, developing eggs (magenta), oviduct (cyan), nuclei (blue).

In vitro fertilisation and egg activation in Drosophila

Supervisor:Professor Tim Weil

Embryo development in animals begins with egg activation which initiates the transition from an arrested egg to a cell competent to begin embryogenesis. These essential events are coordinated by fundamental cell and molecular processes. Using Drosophila, previous work in the lab has revealed that osmotic pressure, calcium ion increases, and reorganisation of the cytoskeleton are all key factors in the initiation of egg activation. However, our understanding of events downstream is limited by the biology of Drosophila: internal fertilisation following egg activation.  

This project aims to overcome this challenge by establishing in vitro fertilisation (IVF) in Drosophila for the first time. This will involve micro-manipulation and injection of gametes, as well as exploration of what the minimalist system is for fertilisation. Taking advantage of the genetic tractability, imaging options, and ease of manipulation of Drosophila, once an IVF technique is functioning, we will then test the relevance of sperm entry, how the pronucleus forms, what initiates mitosis, if there are cytoskeletal changes, when translation of maternal transcripts occurs, and more. This project will involve advanced imaging, genetics, pharmacological disruption, and physical manipulation. In addition to establishing an exciting new method, results from this project will likely have implications on research on IVF in other animals, including humans, since the cytoplasmic environment of the egg is known to be important for successful IVF in mammals. 

For more information, please visit WeilLabCambridge.com or contact Prof Tim Weil at tw419@cam.ac.uk

References

York-Andersen AH, et al., Osmolarity-regulated swelling initiates egg activation in Drosophila. Open Biol. 2021; 11: 210067. 
doi.org/10.1098/rsob.210067

Sartain CV, Wolfner M, Calcium and egg activation in Drosophila. Cell Calcium. 2013; 53(1). doi: 10.1016/j.ceca.2012.11.008