Insect eggs and sperm: evolutionary and biophysical interactions

Insect eggs and sperm are stunningly diverse. Yet, there are major unknowns in the way insect eggs and sperm interact during fertilisation because this happens inside the female’s body. Recent research has summarised thousands of studies in large datasets of insect sperm length (>4700 species) and insect egg size (>6700 species), yet matching data from sperm and egg size is scarce. This is hindering our understanding of the coevolution of sperm and eggs, for which selection on one, must pose constraints on the other. It is also a barrier in our understanding of sperm entry into the egg, both at the surface and into the channel leading to the egg interior. In contrast to vertebrates where fertilisation is well characterised, the internal fertilisation of insects poses challenges which have prevented our understanding of sperm movement into the egg so far. The complex egg surface architecture at the site of sperm entry, the micropyle, is a critical avenue for research.

This 3-year funded PhD studentship has three main objectives: 1) assemble the first dedicated collection of insect eggs capitalising on existing complementary sperm data, for long-term preservation and future accessibility; 2) characterise morphological variation of egg surface diversity at the site of sperm entry to identify key transitions in morphological evolution across insects; 3) use physical reality to recreate sperm movement over the egg surface using a combination of experimental tests and mathematical models. You will use museum collections and other sources to assemble a comprehensive collection of insect eggs, then with a combination of microCT scanning and surface tomography, you will image the eggs in detail for phylogenetic analyses. Geometric morphometrics (shape analysis) will reveal the morphological diversity of insect eggs, allowing you to model sperm movement across the egg surface.

You will work alongside an interdisciplinary team with Dr Graziella Iossa, an expert on insect eggs and micropyles, Professor Carl Soulsbury, who is developing cutting edge microfluidic devices and live imaging techniques for insect sperm, Dr Adnan Morshed, a mathematical modeller, and a postdoctoral research assistant.

Details to apply

The deadline for applications is 31/05/2026. The application is only open to home students. For any queries, please contact Dr Graziella Iossa, giossa@lincoln.ac.uk

Please send a 2-page CV and a cover letter addressing the following points: 1) why you are interested in this PhD studentship; 2) your background and how this fits within the project; 3) how would this PhD further your career goals to cohsstudentships@lincoln.ac.uk