Can worms help women pause biological clocks?

A study by researchers from the Hebrew University of Jerusalem has found a potential method to slow down egg maturation, which could reduce birth defects in babies born to older mothers and allow women to have babies later in life.

Does this mean that women could press pause on their biological clocks?

Not quite yet, according to a release published by the university on Monday. However, while it is a little too early for humans, Dr. Yonatan Tzur and Dr. Hanna Achache, researchers at Hebrew University’s Genetics Department, have discovered the switch that may do this in worms. And they’re hopeful this breakthrough may help women extend their fertility windows and maintain high egg quality into their 30s and 40s.

Working with scientists at Harvard University, the team studied egg maturation in roundworms, as they contain the same 20,000 genes as humans do and their eggs mature in about one day. They were able to pinpoint an exact gene (ogr-2) that controls the rhythm of egg maturation.

Delving further, the team studied MAP Kinase (“MAPK”), the biochemical switch that turns egg development on and off. When they removed the ogr-2 gene with CRISPR gene-editing technology, MAPK went into overdrive and the worms’ eggs aged very quickly.

CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats, which are the hallmark of a bacterial defense system that forms the basis for CRISPR-Cas9 genome editing technology. With CRISPR, researchers can permanently modify genes in living cells and organisms and, in the future, may make it possible to correct mutations at precise locations in the human genome in order to treat genetic causes of disease.

“We tested the gene’s role by removing it from the worm’s gene sequence,” Tzur explained. “Instantly, these ‘edited’ worms became less fertile and their eggs more closely resembled those of an older worm.”

The HU researchers’ findings were recently published in the scientific journal Genetics.

Human eggs begin to mature from the onset of a woman’s first period. However, the average age at which women are having their first children is continually rising.

A 2018 report found that the average age of first-time mothers in the United States is 26, up from 21 in 1972, and for fathers it’s 31, up from 27. Women are having babies later in other developed countries, too: in Switzerland, Japan, Spain, Italy and South Korea, the average age of women during their first birth is 31.

This new discovery could create a way to delay egg aging without losing egg quality.

Tzur said that one possibility might be to gently increase the equivalent of ogr-2 in girls via a food additive. Another would be to suppress MAPK during the in vitro fertilization cycle, which would help older eggs complete their development and improve women’s chances of having a healthy baby as they get older.