Scientists at Northwestern University have discovered that sparks literally fly at the moment of conception – and not just in the bedroom. An explosion of zinc fireworks happens when sperm activate a human egg, and the size of the sparks is a direct measure of the quality of the egg and its possibility of developing into an embryo. The finding could offer new hope for the success of in vitro fertilization (IVF) as scientists may be able to choose the best eggs.
This is the first time that there has been documentation of the zinc sparks in a human egg. The eggs were activated by an injection of sperm enzyme, triggering an increase of calcium within the egg, and zinc released from the egg. Actual sperm were not used in the study because federal law prohibits it in human research.
Teresa Woodruff, an expert in ovarian biology at Northwestern and one of the study’s two senior authors, said “It was remarkable. We discovered the zinc spark just five years in the mouse, and to see the zinc radiate out in a burst from each human egg was breathtaking.”
She said that the biology all begins at the time of fertilization, but we still know next to nothing about what happens in a human at that moment.
Woodruff said that the zinc spark at the moment of conception indicates immediately which eggs are the best ones to transfer in IVF. “It’s a way of sorting egg quality in a way we’ve never been able to assess before.”
The study was published in Scientific Reports on April 26.
Photo and video credit Northwestern University.