Scientists have for the first time discovered a protein that plays a critical role during sperm-egg adhesion and fusion that could help in the diagnosis and treatment of infertility. The new discovery could also pave the way for the development of better contraceptives.
The protein has been named Maia, the Greek goddess of motherhood.
The research conducted by an international team led by Kateina Komrsková from the Institute of Biotechnology of the Czech Academy of Sciences found that also highlights the development of cell cultures for the “production” of human oocyte proteins.
The study published in the journal Science Advances states that gamete fusion is a critical event of mammalian fertilization and the team discovered a new Fc receptor-like protein 3 on the human egg that binds to a key sperm protein. The interaction of the protein and adhesion leads to human sperm-egg fusion and the creation of life.
“This is the result of nearly two decades of research and of extensive international collaboration the publication includes 17 different affiliations from around the world, including the UK, the US, and Japan,” Komrskova said in a statement. The study initially began in Harry Moore’s lab at the University of Sheffield in the United Kingdom.
The team was using the One-Bead One-Compound (OBOC) assay method to look for mutations that cause tumours, during which interacting partners bind to special beads, and began looking for receptors on the surface of the egg cell, which are key factors in sperm interaction and which are still unknown to science.
“We created hundreds of thousands of different beads, each with a segment of protein on its surface. We incubated these beads with human sperm and isolated those that interacted with each other. After a number of experiments, we were able to identify a candidate fusion protein,” Komrskova explained.
The team had to negotiate their way through several challenges including how to obtain ethical committee approval for the research first since the protein can only be found in humans. The approval took over two years to use human eggs and sperm for the research.
“We also developed special cell cultures that mimicked the egg. These cells were then capable of ‘producing’ proteins that are normally found on the surface of a human egg, which made it possible for us to conduct a range of experiments,” the lead researcher added.
They were able to spot microvilli on the surface of the human egg, covered by the signal that belonged to the protein they discovered.
They are hopeful that the discovery of the protein could lead to the improvement of infertility treatment methods as well as the development of future contraceptives.
“Fertilisation is a crucial moment in human life, yet there is a lot we still do not know about it. Such new findings that contribute to the understanding of physiological processes can find direct application in human medicine,” Komrskova concluded.