U.S. scientists say they have a new understanding of the process cells use to ensure sperm and eggs begin life with exactly one copy of each chromosome.

That’s a process, researchers say, which must be closely regulated to prevent problems such as miscarriages and mental retardation.

The study reportedly reveals how glue-like protein complexes release pairs of chromosomes at precisely the moment of meiosis — the specialized cell division process that produces sperm and eggs — enabling them to separate properly.

The findings by the Massachusetts Institute of Technology researchers — led by Howard Hughes Medical Institute investigator Angelika Amon — appear in the journal Nature.