Natural fertilization is a highly selective process in which the female reproductive tract allows only very few sperm cells to proceed to the vicinity of an unfertilized oocyte. Our recent findings have revealed that the probability of sperm to fertilize the oocyte can be strongly dependent on the genetic compatibility of the reproductive partners. However, the molecular mechanisms of genetic compatibility and fertilization are extremely weakly known. In this study, we will clarify these mechanisms in humans by testing the novel idea that the female reproductive tract induces selective changes in sperm gene expression (at the RNA and protein level) and this way bias the fertilization towards specific (genetically compatible) males. Besides increasing understanding of these unknown mechanisms, our study can pave the way towards more personalized infertility diagnostics and treatments as well as facilitate deeper understanding of reproduction and mechanisms of inheritance.

2025

2029