Forgotten and Overlooked Structure Attached to the Ovary May Be Far More Active Than Once Thought

The rete ovarii (RO) is a small, network-like structure attached directly to the ovary that has long been overlooked in medical understanding. Despite its presence across various mammals, including humans, the RO's function has been a mystery since its discovery over a century ago. Traditionally dismissed as a simple, functionless remnant, a recent study published in eLife in March 2025 has revealed the RO's potential significance.

Using cutting-edge imaging and molecular techniques, researchers at Duke University Medical Center have discovered that the RO may be far more active and complex than previously thought. They identified three distinct regions of the RO that remain present in adult animals, some of which form hollow tubes capable of moving cellular material and fluids toward the ovary.

Additionally, many proteins secreted by cells within these hollow spaces could potentially influence ovary function. The RO's connection to nerve fibers also suggests it may act as a sensory structure, helping the ovary respond to surrounding signals. This research indicates that the RO may play a role in maintaining the ovary and supporting its development, potentially making it an essential component of the female reproductive system alongside other organs.

However, more studies are needed to fully understand the RO's functions and how it responds to hormones and other bodily signals.