scientists just captured Something Extraordinary At The moment Of Fertilization

 

Health and Medicine

Photo credit: The newly discovered human "zinc spark". Northwestern News/Duncan et al. 2016

Sparks really do fly when the magic happens. At the exact moment a sperm penetrates an egg, the latter releases billions of zinc atoms from its surface which spark off. Using fluorescent microscopy, these sparks emit a light, which can then be filmed. The discovery that human eggs cells undergo this process could lead to new ways for doctors to identify viable eggs for in vitro fertilization (IVF).
“It was remarkable,” explained Teresa Woodruff, one of the two senior authors of the paper published in Scientific Reports. “We discovered the zinc spark just five years ago in the mouse, and to see the zinc radiate out in a burst from each human egg was breathtaking. All of biology starts at the time of fertilization, yet we know next to nothing about the events that occur in the human.”
The scientists were able to image the zinc sparking off the human eggs by injecting them with an enzyme released by the sperm when they hit the egg in normal circumstances. They weren’t allowed to use actual sperm due to restrictions on human research under federal law, but previous studies using mouse eggs and sperm have shown the same thing happen. The enzyme from the sperm triggers the calcium in the egg to increase and the subsequent release of zinc.