From bedside to bench and back again
By Noga Martin
Dr. Noa Lavi-Shoseyov always wanted to work as a clinician, not a researcher. After earning her MD at the Hebrew University of Jerusalem in 2014, she spent six years as an intern and then an obstetrics and gynecology resident at Kaplan Medical Center in Rehovot. She is currently a physician in the hospital’s Fertility and In Vitro Fertilization Unit.
“I love my patients. I love working in a hospital, the work in the clinic,” Dr. Lavi-Shoseyov says.
During her residency, on the recommendation of friends, she spent her required six-month basic science rotation in the groups of Profs. Michal Neeman and Nava Dekel in the Weizmann Institute’s Department of Immunology and Regenerative Biology.
“My friends said, stay on and do a PhD. I said, ‘No, I want to be a clinician.’ But I started exploring my research subject and got to know Michal and Nava, who are both amazing women, very impressive. They’re wonderful role models for women, both in terms of their professional success and their ability to work in a way that’s very collegial, very collaborative and open.
“I really liked them both, and my research created an opening to a new world,” she says.
Lowering health risks
As a PhD candidate, Dr. Lavi-Shoseyov is exploring why the vast majority of a woman’s oocytes (egg cells) die while in their dormant state, without ever being activated and ovulating. Women are born with a “reserve” of one million oocytes. Over the course of their lifetime, only about 5,000 of these cells will be activated into the ovulation process, and only 500 or so will ovulate, potentially resulting in a pregnancy.
Discovering the key to this process might lead to methods of delaying it and thereby postponing the onset of menopause. While menopause is known to be a considerably uncomfortable time for women, characterized by unpleasant symptoms like hot flashes, weight gain, and mood swings, it also involves a massive hormonal transition that carries major implications for women’s health, ranging from osteoporosis to cardiovascular disease—the leading cause of death for women worldwide.
When a woman’s reserve of oocytes is depleted prematurely, she is at much higher risk (as high as a factor of 10) of developing menopause-associated health conditions. Conversely, research has shown that the later a woman goes through menopause, the lower her risk of these conditions.
“The moment we lose our ‘estrogen factory,’ it starts to become a problem,” Dr. Lavi‑Shoseyov explains.
She and her colleagues used a model developed by a former member of the group, in which a protein called vasorin [see sidebar] is knocked out from the growing follicles of female mice. This resulted in a decrease in the number of dormant primordial follicles, while the number of activated ones remained the same, making their model a potentially effective method of probing how follicles die.
For Dr. Lavi-Shoseyov, pursuing a PhD is a path to exploring the basic science of her chosen field, not a goal in and of itself to earn the degree.
“The PhD is a way to conduct research. It’s what allows me to do my research here—all due to the six months I spent here and [under Prof. Neeman’s and Prof. Dekel’s] guidance.”
This year, Weizmann is welcoming the first cohort of students to its combined MD-PhD program, as part of the Miriam and Aaron Gutwirth Medical School. When asked what makes a physician who returns to basic research different from one trained in an MD-PhD program, Dr. Lavi-Shoseyov says, “I think I’m here with a more defined outlook compared to students who do a PhD while in medical school and haven’t chosen a direction. They tend to choose their research and select a specialization based on that. I’m here because of the needs I see and my experience in clinical work.”
Growing up around science
“I was definitely raised in a medical environment,” Dr. Lavi-Shoseyov says. Her mother, Dr. Nurit Shoseyov, is a family doctor, and her father, Dr. David Shoseyov, is a pediatric pulmonary specialist and researcher. Her uncle, Prof. Oded Shoseyov, is a scientist at Hebrew University and a serial biotech entrepreneur.
She is married to Dr. Amir Lavi, an oral and maxillofacial surgeon, and has two daughters, ages 6 and 9, who are growing up around science and medicine. They visit her on campus and spend time at the hospital while she is on call.
“The younger one says she wants to be a doctor, and I think there’s a good chance she will be, because she really shows an interest. I had stitches removed, and she came up to watch.”
“Since I’ve been at Weizmann, they’re both very interested in science,” Dr. Lavi-Shoseyov adds. “The older one plans to be a scientist at Weizmann herself.”
The follicle code
In March 2025, Dr. Noa Lavi-Shoseyov was the first speaker at the Weizmann Institute’s International Day of Women in Science, an annual event on campus that features short lectures by women scientists covering a wide range of fields. Dr. Lavi-Shoseyov discussed her group’s work with the protein vasorin, which is usually studied in the context of blood vessels, but which Prof. Nava Dekel demonstrated plays a role in the basic physiology of the ovary.
Prof. Dekel and her team discovered that removing vasorin from ovarian cells in female mice changed the number of immature egg cells. This finding suggests that follicles in the ovary send signals to one another to regulate these dormant eggs—a process scientists are only beginning to understand. Dr. Lavi-Shoseyov believes vasorin may play a key role in that communication, influencing which follicles survive and which do not. “We don’t know what this is or how it works. This is one direction of my research,” she says.
The study offers new clues that could help preserve fertility and improve women’s reproductive health.
Michal Neeman is supported by:
The de Picciotto Cancer Cell Observatory In Memory of Wolfgang and Ruth Lesser
The Sagol Institute for Longevity Research
The Helen and Morris Mauerberger Professorial Chair in Biological Sciences