Scientists have caught the flash of light that happens when a sperm meets an egg

Scientists have taken pictures of the flash of light that happens when a human sperm cell touches an egg for the first time ever.

Animals have been seen to do this before, but no one has ever seen the spark of a human pregnancy. And what’s even more amazing is that some eggs burn brighter than others, which a team from Northwestern University found is a direct sign of how well they can grow into healthy embryos.

So why do sparks really fly when a baby is being made? In 2011, a team from Northwestern found that sparks of zinc went off when mice were being born.

It took them a few years to figure out how to capture this event on film, but in 2014, they did it for the first time ever. They watched as billions of zinc atoms were released at the exact moment a sperm cell pierces an egg of a mammal.

Using a new fluorescent sensor that can track how zinc moves in living cells, the team was able to see how an egg stores zinc. They found about 8,000 zinc compartments, each with about 1 million zinc atoms that were just about to explode. After fertilization, the tiny “fireworks” that come out last for about two hours.

Now, the same group has figured out how to film this happening in a human egg at the time of conception.

Teresa Woodruff, who was on the team, says, “It was amazing.” “We found the zinc spark in the mouse just five years ago, and it was amazing to see the zinc burst out from each human egg.”

If you pay close attention to health science news, you’ll know that most studies, even the most promising ones, fall short of their goals. Maybe what worked for mice didn’t work for people, or maybe what worked in the lab couldn’t be done on living things. It’s possible that the researchers just ran out of money.

But in this case, we can see how quickly the team went from studying mice to studying humans. In just five years, they figured out something that could change a lot of people’s lives: the flashes of light that have now been seen in humans for the first time can be used to tell if an egg is healthy enough to be fertilized.

That’s a big deal for couples who use IVF because about half of the fertilized eggs don’t develop properly because of a genetic mix-up that can’t be helped.

Eve Feinberg, one of the researchers, says, “This is an important discovery because it may give us a way to check the health of an egg and, in the future, an embryo before implantation that doesn’t hurt them and is easy to see.”

“Right now, there are no tools that can tell us if it’s a good egg,” she says. “Often, we don’t know if an egg or embryo is really viable until we see if it leads to a pregnancy. That’s why this is so important. If we can tell right away what is a good egg and what isn’t, we’ll know which embryo to transfer, save a lot of heartache, and get pregnant much faster.”

For the experiment, the team used a sperm enzyme to wake up the egg, since using real sperm to fertilize an egg for research purposes is against US federal law. They then watched as the calcium levels in the egg rose, which caused zinc to be released.

Sarah Knapton of The Telegraph says, “As the zinc shoots out, it binds to small molecules that give off a fluorescence that can be picked up by camera microscopes.”

So what makes zinc so unique? The researchers found that eggs divide and distribute zinc to control the development of a healthy embryo. The mineral plays a key role in controlling the “decision” the egg makes to grow into an embryo, so the more zinc that is released, the brighter the flash and the more viable the egg.

One member of the team, Thomas O’Halloran, said back in 2014, “The egg must first store zinc and then release some of it for maturation, fertilization, and the start of embryogenesis to go well.” “But how much zinc is used in this amazing process, and where in the cell is it?”

Researchers should be able to answer this question now, and we can’t wait to see what they find next.