MOTIONSPERM · Biomechanics, fluid dynamics and evolution of collective and cooperative motility of insect spermatozoa using microfluidic devices

Spermatozoa show great morphological diversity and share the function of fertilisation. They are often found as single cells, but in some organisms, such as insects, they can form aggregates ranging from two to hundreds of cells. One of the most intriguing parts of this phenomenon is the coordinated motility and improved swimming performance and reproductive success. Research on sperm motility in insects is still largely unexplored, with most studies focusing on vertebrates. The MOTIONSPERM project seeks to address this research gap by analysing the biomechanics and fluid dynamics of different types of sperm aggregates and insect species and placing these findings in an evolutionary context. The collective motility of sperm aggregates is influenced by both their cellular characteristics and the microenvironmental conditions of the reproductive organs where they swim. These include the properties of the reproductive fluids and the geometry of the organs. I will use advanced microscopy techniques, 3-D reconstruction of reproductive tracts, and innovative measurement of fluid viscosity and viscoelasticity to perform microfluidic device assays that simulate realistic reproductive models, allowing us to observe sperm motility under conditions that closely mimic their natural environment. Reproductive traits, including sperm motility novelty, will be investigated in a temporal phylogenetic frame. This project will contribute to a deeper understanding of insect aggregate sperm motility and its impact on fertility, sperm competition, evolution and cooperative cellular functions. In addition, the project will produce relevant and high-impact research results, potentially applicable to sustainable agriculture, future biomedical applications and public health plans in the EU. The project will also enrich my research skills in advanced techniques, enhancing my professional competitiveness and increasing my abilities and potential for an independent and successful career.