Unique Physiological Mechanisms of Sperm Storage and Prolonged Sperm Survival in Hen Oviducts: A Review.

Poultry sperm survive for extended periods within sperm storage tubules (SSTs) located at the uterovaginal junction (UVJ) of the oviduct, and their survival period is directly correlated with fertility. In this review, the mechanisms underlying sperm longevity in SSTs are discussed, with a focus on recent discoveries related to the functions of SSTs and UVJ tissue. In particular, the possible role of fatty acids and exosomes secreted by SST cells in sperm survival are discussed. Subsequently, the importance of gonadal steroid receptors in maintaining the integrity and function of the SSTs is described. Additionally, the role of the local immune system in protecting sperm from infection and facilitating the selection of high-quality sperm is discussed. Disruption of these SST functions may result in reduced fertility. This review provides updated information on the mechanisms that enable prolonged sperm survival in SSTs.