Scientists Create First Map of a Human Ovary: What to Know

Advancing Women’s Health Research

Historically, women’s health research has been underfunded and underrepresented, but the authors believe their atlas of the ovary is a significant step forward.

“There are a lot of biological questions that we don’t know the answers to about the ovary,” said Dr. Shikanov.

One of the biggest mysteries is why so many eggs never become fertilizable. Each human female is born with about one to two million ovarian follicles. Each follicle carries one immature egg. Around puberty, two thirds of these follicles die off. And most that are left never develop into fertilizable eggs.

“The majority of these follicles either just grow and secrete hormones or undergo atresia,” Dr. Shikanov said. “One question that we wanted to understand is, what determines an egg that can grow, ovulate, and become a fertilizable egg and potentially develop into a new human being from one that does not?”

Another big question researchers have is, what’s happening with other types of cells in the ovary — the supporting cells that produce endocrine hormones? Where are they located and what proteins and RNA are they making? Their research begins to unravel some of these questions and lays a foundation for future studies.

“We wanted to analyze the transcriptional signatures from specific regions and then do bioinformatical analysis and really combine structure, function, and transcriptional signatures,” Dr. Shikanov said.

Knowing the transcriptional signatures can help researchers understand disease mechanisms and then go on to develop treatments for these diseases.

Winifred Mak, MD, PhD, a reproductive endocrinologist and infertility specialist at Dell Medical School, University of Texas, Austin, studies cancer fertility preservation. “For me, it is interesting to see that there are so many different clusters of cells in the ovary that have been identified by this study that we were not necessarily aware of before,” said Dr. Mak, who is not involved in the new research. “Also, the identification of new genes not previously studied in the human ovary.”
 

What’s Next

Dozens of scientists who study reproductive health are already reaching out to the researchers about their work, Dr. Shikanov said.

“We get contacted almost every day from researchers all around the world asking for data sets or asking for details from this paper,” she said, “from people who study ovarian cancer, for example.”

Dr. Mak said having a map of a normal ovary could also help researchers who study premature ovarian insufficiency — why the ovary sometimes goes into premature menopause — and polycystic ovarian syndrome.

Another big area of research interest is ovarian aging. “Women live so much longer now, but we still reach menopause at the age of 50,” Dr. Shikanov said. “So, there are efforts going toward understanding ovarian aging and maybe preventing it to extend ovarian longevity.”

Dr. Mak said it will enable scientists to “look at different age women and see what genes change across the reproductive lifespan.”

The atlas may also eventually lead to treatments that help restore fertility in individuals who had and were treated for cancer as children, people who undergo sex transitions, and those whose reproductive organs have been impacted by trauma in conflict settings or accidents, Dr. Li said.

The applications are numerous and exciting, Dr. Shikanov said. “Our atlas is like a benchmark. Now researchers can collect ovaries from individuals with these diseases and conditions and try to compare what’s different.”

A version of this article appeared on Medscape.com.