Fluorescent microscopy clearly shows the chemical fireworks that occur when a sperm fertilizes an egg. This small but most exciting phenomenon was discovered in 2016.
The zinc spark was discovered five years ago in mice. It was amazing to see the zinc explosion radiating from human eggs as well
Theresa Woodruff, a former researcher at Northwestern University says.
After the two cells meet, zinc atoms burst from the egg, accompanied by a visible flash of light. Zinc oscillation serves several purposes: on the one hand, it pulls the curtains in front of other sperm, and on the one hand, it chemically blocks them. On the other hand, it converts the cell from meiosis to mitosis, i.e. it begins the division of a new organism.
Recent research indicates that this phenomenon is inherited from vertebrates. Fireworks have also been observed in mice, cattle, macaques, and South African claws, from which the branch of mammals shifted 300 million years ago during tribal evolution.
Photo: Northwestern University
Northwestern University employees studied the mechanism on clawed frog eggs. For research published in Nature Chemistry, frog eggs were an ideal subject because they are bulky compared to mammalian eggs. The researchers were able to find the substance in microscopic blisters on the surface of the egg, in which the concentration of zinc was ten times that of the rest of the cell. According to their results, manganese also played a role in this process, but we do not yet know if this is the case in mammals.
The brightness of zinc fireworks is an important indicator of the viability of the resulting embryo, which is very important information in IVF. It’s also important new knowledge that dietary zinc can play a role in fertility.
