New research shows possibility of human reproductive period extension

Researchers have identified a drug that could extend egg viability in worms, which may extend women’s fertility by three to six years in theory.

According to Science Daily, an American science news website, Coleen Murphy, who led the study, specialises in using microscopic worms, Caenorhabditis elegans (C.elegans) to study longevity because it has many of the same genes as humans.

Researchers discovered several years ago that C. elegans’ unfertilised eggs (oocytes) showed similar declines in quality with age as human eggs.

Murphy found the question of how to maintain egg quality with age had been ignored by former researchers.

She stressed that women experience declines in fertility and increased rates of miscarriage mainly because of declining egg quality rather than a lack of eggs.

Thus, Murphy and her team tried to find a kind of drug that could help women to preserve the oocytes in their mid-30s.

For the study, day three of worms’ adulthood was chosen as an experimental subject, the equivalent of women in their early 30s.

The results showed that when a key protein, “cathepsin B,” in old and poor-quality C.elegans oocytes was inhibited midway through the fertility window, the egg viability was extended beyond the normal span.

In addition, they also found that when the “cathepsin B” genes were knocked out entirely, the worms’ fertility was increased by about 10 per cent, which could be a three- to six-year extension of the reproductive period, according to the study.

Yet Murphy admitted it is hard to believe that microscopic worms could have anything in common with mammals and the cathepsin B inhibitor is far away from being tested in humans.

She still felt excited she had found something new in worms, which indicated the study might also be conducted on mammals.

What’s more, Murphy and her colleagues have discovered a cattle breeding study that found that “cathepsin B” proteins that affect the C. elegans oocytes play the same role in cows, which may support Murphy’s theory.(Xinhua/NAN)