Scientists have witnessed mammalian eggs explosively releasing zinc atoms just after fertilization in a series of brief, intense outbursts that appear to jumpstart embryonic development. . . .Toward the end of its 18-hour window of viability,
a mouse egg takes up more than 20 billion zinc atoms. This seems to signal the egg to sit tight, and the cell becomes quiet. But once a sperm hits its mark, the zinc bursts of out the egg.Zinc sparks! Who knew?
These outbursts are dynamic. . . . In eggs of mice and two kinds of monkey, the team observed between one and five explosive bursts of zinc during the 90 minutes after fertilization. The release of the metal, which is linked to fluctuating levels of calcium, appears to signal the fertilized egg’s readiness to grow into a multicellular blob, and eventually an embryo. The team confirmed zinc’s role by manipulating the egg’s access to the metal.