Egg meets sperm: The female side of the story

Oct 21, 2010

Researchers at the Swedish medical university Karolinska Institutet have been able to describe the 3D structure of a complete egg receptor that binds sperm at the beginning of fertilization. The results, published in the journal Cell, will lead to better understanding of infertility and may enable entirely new types of contraceptives.

For centuries, the imagination of people has been grasped by the encounter of gametes – egg and sperm-, whose union gives rise to a new individual. At the beginning of conception, binds to proteins in the extracellular coat of the egg, called zona pellucida (ZP). But the molecular details of this fundamental biological event have so far remained obscure.

Luca Jovine's research team at Karolinska Institutet has now managed to determine the three-dimensional structure of the receptor molecule that binds sperm, called ZP3 (see press photos). The detailed structural information, based on data collected at the European Synchrotron Radiation Facility (ESRF), makes it possible to begin exploring at the molecular level how the egg interacts with sperm at fertilization.

The study suggests which parts of the receptor are likely to be directly contacted by sperm, and provides new insights into how the sperm receptor is assembled and secreted from the egg. The findings have important implications for human reproductive medicine, as they may explain how mutations in the sperm receptor gene could cause . The research could also potentially lead to the design of non-hormonal contraceptives specifically targeting egg-sperm interaction.

"The results give a remarkable picture of the female side of fertilization", says Luca Jovine, who has led the study. "But this is, of course, only half of the story. The next step will be to tackle the corresponding molecules on sperm that allow it to bind to the egg."

Explore further: Cell division speed influences gene architecture

More information: "Insights into Egg Coat Assembly and Egg-Sperm Interaction from the X-Ray Structure of Full-Length ZP3", Ling Han, Magnus Monné, Hiroki Okumura, Thomas Schwend, Amy L. Cherry, David Flot, Tsukasa Matsuda & Luca Jovine, Cell, 21 October 2010.

add to favorites email to friend print save as pdf

Related Stories

Rodent sperm work together for better results

Jan 24, 2007

Although, sperm are inseminated in millions each sperm goes it alone. However, under some circumstances it might be advantageous for sperm to cooperate with one another. This is especially likely to be the case when females ...

Researchers Develop Test to Identify 'Best' Sperm

May 20, 2010

(PhysOrg.com) -- Researchers at Yale School of Medicine have discovered a method to select sperm with the highest DNA integrity in a bid to improve male fertility. The method is comparable to that of the egg’s ...

Recommended for you

Cell division speed influences gene architecture

21 hours ago

Speed-reading is a technique used to read quickly. It involves visual searching for clues to meaning and skipping non-essential words and/ or sentences. Similarly to humans, biological systems are sometimes ...

Secret life of cells revealed with new technique

22 hours ago

(Phys.org) —A new technique that allows researchers to conduct experiments more rapidly and accurately is giving insights into the workings of proteins important in heart and muscle diseases.

In the 'slime jungle' height matters

23 hours ago

(Phys.org) —In communities of microbes, akin to 'slime jungles', cells evolve not just to grow faster than their rivals but also to push themselves to the surface of colonies where they gain the best access ...

Queuing theory helps physicist understand protein recycling

Apr 22, 2014

We've all waited in line and most of us have gotten stuck in a check-out line longer than we would like. For Will Mather, assistant professor of physics and an instructor with the College of Science's Integrated Science Curriculum, ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

freethinking
1 / 5 (2) Oct 24, 2010
egg and sperm-, whose union gives rise to a new individual.

Sound just what pro-life people say. Once egg and sperm unite we have a new individual. Basic Science 101 - denied by those for abortion.
O2BOOM
not rated yet Oct 26, 2010
egg and sperm-, whose union gives rise to a new individual.

Sound just what pro-life people say. Once egg and sperm unite we have a new individual. Basic Science 101 - denied by those for abortion.

Let's be realistic, would you rather have kids born into conditions where they are prone to abuse malnourishment and horrible parents, or a few abortions?

Besides, miscarriage happens in nature very often.

The real problem is promiscuous sex, though how do you stop that in a non violent way without education?

More news stories

When things get glassy, molecules go fractal

Colorful church windows, beads on a necklace and many of our favorite plastics share something in common—they all belong to a state of matter known as glasses. School children learn the difference between ...

SK Hynix posts Q1 surge in net profit

South Korea's SK Hynix Inc said Thursday its first-quarter net profit surged nearly 350 percent from the previous year on a spike in sales of PC memory chips.