In vitro fertilisation and egg activation in Drosophila
Supervisor
In animals, embryo development starts with egg activation and fertilisation. These essential events involve fundamental cell and molecular processes as well as ensure that only one sperm enters the egg. Using Drosophila, an attractive model organism for this research due to its genetic tractability, imaging options, and ease of manipulation, previous work in the lab has revealed that osmotic pressure, calcium entry, and reorganisation of the cytoskeleton are all key factors in the initiation of egg activation. However, our experimentation on egg activation and understanding of downstream events is limited by the biology of Drosophila: internal fertilisation and temporally separated egg activation and fertilisation.
This project will aim to overcome this barrier by establishing a protocol for in vitro fertilisation (IVF) in Drosophila. This will involve micro-manipulation and injection of gametes, as well as exploration of what the minimalist system is for fertilisation. With IVF functioning, we will then test the relevance of sperm entry, requirement of the sperm tail, how the pronucleus forms, what initiate mitosis, if there are cytoskeletal changes, when translation of maternal transcripts occurs, and much more. This second part of the 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 in known to be important for successful IVF.
For more information please visit WeilLabCambridge.com or contact Tim Weil via 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
Image caption: Drosophila female reproductive machinery, developing eggs (magenta), oviduct (cyan), nuclei (blue).