In the quiet and largely invisible drama of human conception, a single step has long resisted direct observation: the moment a sperm meets and joins an egg. Researchers at the University of Sheffield, working with international partners, have now identified a protein they call MAIA, named for the Greek goddess of motherhood, that appears to draw sperm into the egg. Their work, reported in Science Advances, arrives at a time when unexplained infertility still troubles more than half of those who cannot conceive naturally, and it offers a new way of understanding a process that human eggs have,
Newly Identified Protein MAIA Draws Sperm Into the Egg, Opening Paths to Infertility Treatments
In the quiet and largely invisible drama of human conception, a single step has long resisted direct observation: the moment a sperm meets and joins an egg. Researchers at the University of Sheffield, working with international partners, have now identified a protein they call MAIA, named for the Greek goddess of motherhood, that appears to draw sperm into the egg. Their work, reported in Science Advances, arrives at a time when unexplained infertility still troubles more than half of those who cannot conceive naturally, and it offers a new way of understanding a process that human eggs have, until now, been too scarce to reveal.
Researchers at the University of Sheffield and their international partners have identified a protein that helps sperm fuse with an egg, and they have named it MAIA after the Greek goddess of motherhood. The finding, published in Science Advances, addresses a step in human fertilization that has been very hard to study directly.
The obstacle has been both ethical and practical. Human eggs are in short supply for research, and knowledge of human fertility has advanced slowly as a result. That matters, because infertility remains unexplained in more than half of people who cannot conceive naturally.
To work around the shortage, the team built artificial eggs from thousands of beads, each carrying a different peptide that sperm might bind to. When sperm were added, only a few beads caught any. Through several painstaking rounds of discarding beads without sperm, the remaining beads all pointed to one protein, MAIA. The team then placed the MAIA gene into human culture cells, which became receptive to sperm much as an egg would be, leading them to conclude that MAIA draws sperm in.
Professor Harry Moore, the lead investigator, said the technique should deepen understanding of human fertility and open the way to new infertility treatments and future contraceptives. Professor Allan Pacey, a co-author, called it a major step and said it would have been nearly impossible without the beads, since enough eggs could not have been obtained. The work may also shed light on the idea that some sperm are incompatible with some eggs, and the next question is whether sperm from different individuals bind MAIA differently.
Researchers at the University of Sheffield and their international partners have identified a protein that helps sperm fuse with an egg, and they have named it MAIA, after the Greek goddess of motherhood. The finding, published in Science Advances, concerns a step in human fertilization that has been hard to study directly.
The difficulty is a practical one. What scientists know about human fertility has been limited by ethical concerns and by a shortage of human eggs available for research. Meanwhile, infertility remains unexplained in more than half of the people who cannot conceive naturally, so the gaps in understanding have real consequences.
The team worked around the shortage by building artificial eggs. They used thousands of beads, each carrying on its surface a different piece of protein, known as a peptide, that sperm could potentially bond with. The researchers describe it as the first study of its kind.
When sperm were incubated with the beads, only a small number of beads picked up any sperm. The researchers then went through several painstaking rounds of discarding the beads that had no sperm attached. By the end, the beads that remained corresponded to a single protein, MAIA, and sperm were bound to every one of them.
The team then took the gene for MAIA and inserted it into human culture cells. Those cells became receptive to sperm in the same way an egg would be during natural fertilization. From this, the researchers conclude that MAIA is responsible for drawing sperm into the egg.
Professor Harry Moore, lead investigator and a member of Sheffield's School of Biosciences, said the artificial fertilization technique should help scientists better understand the mechanisms of human fertility. He added that it will pave the way for new infertility treatments and could revolutionize the design of future contraceptives.
Professor Allan Pacey, a co-author who heads Sheffield's Departments of Oncology and Metabolism and Infection, Immunity and Cardiovascular Disease, called the discovery a major step forward. He said it would have been almost impossible without the beads standing in for the surface of human eggs, because researchers simply could not have obtained enough eggs for the experiment. He described it as a classic case of thinking out of the box.
The work may also bear on an existing theory: that some sperm are not compatible with some eggs. The researchers now plan to examine whether sperm from different individuals bind to MAIA differently, which could help show whether that incompatibility has a molecular basis.
Citas Notables
The discovery of MAIA is a major step forward in understanding human fertilisation, and would have been almost impossible without the artificial beads.— Professor Allan Pacey, co-author, University of Sheffield
The technique will help scientists understand human fertility, pave the way for new infertility treatments and could revolutionize contraceptive design.— Professor Harry Moore, lead investigator, University of Sheffield
Quieres la nota completa?
Lee el original en News-Medical.net ↗
Economy & Finance