Scientists discover new protein which helps sperm fuse with an egg and could improve fertility treatments

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Scientists discover new protein which helps sperm fuse with an egg and could improve fertility treatments

• New MAIA protein, named after the Greek goddess of motherhood, helps to draw  the sperm into the egg cytoplasm for completion of fertilisation
• Infertility is unexplained in more than half of people who cannot conceive naturally
• The fundamental discovery, made by scientists at the University of Sheffield using pioneering artificial fertilisation techniques, could in future help to improve fertility treatments and develop new contraceptives

Scientists have discovered a new protein which helps sperm fuse to an egg and is fundamental for human fertilisation

The new protein, named MAIA after the Greek goddess of motherhood, could be crucial in helping doctors better understand some aspects of infertility and develop novel treatments. Currently, infertility is unexplained in more than half of people who are unable to conceive naturally.  

In the first study of its kind, the international team of researchers led by the University of Sheffield created artificial eggs using thousands of beads. Each of these beads had a different piece of protein, known as a peptide, on its surface so that sperm could bond with them.

When sperm were incubated with the beads scientists found only a small number of beads had sperm attached to them. After several painstaking rounds of removing any beads that didn’t have sperm bound to them, researchers were eventually left with beads corresponding to one particular protein - MAIA - and sperm bound to all of these beads. 

The gene corresponding to MAIA was then inserted into human culture cells, and these became receptive to sperm in the exact way that it would during the natural fertilisation process.

The findings, published in Science Advances, reveal that during the process, MAIA is responsible for drawing sperm into the egg for fertilisation.

Professor Harry Moore, Lead Investigator of the study from the University of Sheffield’s School of Biosciences, said: “Infertility is unexplained in more than half of those who struggle to conceive naturally. What we know about fertility in humans has been severely limited by ethical concerns and the lack of eggs for research.  

“The ingenious artificial fertilisation technique which enabled us to identify the MAIA protein will not only allow scientists to better understand the mechanisms of human fertility, but will pave the way for novel ways to treat infertility and revolutionise the design of future contraceptives.”

The findings could help to confirm the theory that some sperm may not be compatible with some eggs. Researchers now plan to explore whether sperm from different individuals bind to the protein differently.

Professor Allan Pacey, Co-Author of the study and Head of the University of Sheffield's Departments of Oncology and Metabolism and Infection, Immunity and Cardiovascular Disease, said: “This discovery of the MAIA protein is a major step forward in how we understand the process of human fertilisation. It would have been almost impossible to discover without the use of the artificial beads to replicate the surface of human eggs as we simply wouldn’t have been able to get enough eggs to do the experiment. A classic case of thinking out of the box.”

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Media contact: George Dean, Media and PR Assistant, University of Sheffield, 07984 335 211, g.r.dean@sheffield.ac.uk

Notes to editors:

The University of Sheffield

With almost 29,000 of the brightest students from over 140 countries, learning alongside over 1,200 of the best academics from across the globe, the University of Sheffield is one of the world’s leading universities.

A member of the UK’s prestigious Russell Group of leading research-led institutions, Sheffield offers world-class teaching and research excellence across a wide range of disciplines.

Unified by the power of discovery and understanding, staff and students at the university are committed to finding new ways to transform the world we live in and develop solutions to society’s biggest challenges.

Sheffield researchers use their expertise to tackle some of the biggest issues of our time together with partners ranging from SMEs to some of the world’s biggest companies, from across the South Yorkshire region, the UK and beyond.

The University of Sheffield provides an outstanding student experience for its students, with the number one Students’ Union in the UK and both undergraduate and postgraduate degrees that help its students stand out in the jobs market and develop successful careers after graduation, wherever they choose to live and work.

Sheffield has six Nobel Prize winners among former staff and students and its alumni go on to hold positions of great responsibility and influence all over the world, making significant contributions in their chosen fields.

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