A recent study conducted by researchers at the University of Rochester School of Medicine has found the specific cell located in the ovaries that not only governs the timing of ovulation but also plays a major role in fertility. This finding has the potential to reveal major clues that can ultimately help to remedy infertility among individuals who have irregular or disrupted sleep schedules due to shift work or frequent jet lag.

Infertility and in vitro process

By definition, infertility is the failure to conceive after having unprotected sex for a year. The research has found that theca cells, which help the development and release of eggs from the ovaries, are vital for helping the body maintain a cyclic window of sensitivity to the lutenizing hormone, or LH, that begins ovulation.

According to the findings of Michael Sellix, Ph. D., assistant professor of medicine, the theca cells utilize a circadian clock that essentially controls the timing of the production of LH. A circadian rhythm is our body’s natural clock, which occurs in 24-hour cycles and exists in nearly all of the cells that comprise the human body. These clocks also allow organizations to change based on predictions about the environment, like when a mate will be available.

Female reproduction and ovulation heavily depend on a well-functioning circadian rhythm; if these rhythms are interrupted, then it can mean bad news for a woman’s reproductive system and fertility.

“The timing system and how these things are coordinated is such a critical feature of normal function among women,” said Sellix. “We need to use basic experiments like this one to think about how to target this system to aid in recovery from those detriments to fertility.”

For the study, Sellix disrupted the circadian rhythm in the theca cells of mice. Additionally, his team of researchers blocked the LH signaling in the mice. Animals that had a disrupted clock in their theca cells experienced a mitigated sensitivity to LH, resulting in lower rates of ovulation.

Ultimately, Sellix hopes that this knowledge will lead to further studies and infertility therapies that target theca cells.