Sperm‐oviduct interactions: Key factors for sperm survival and maintenance of sperm fertilizing capacity

Abstract

Background: Although millions or even billions of sperm are deposited in the female genital tract, only very few sperm reach the oocyte, and only one single spermatozoon will successfully fertilize. During the journey of the sperm within the female genital tract, the interactions between spermatozoa and fallopian tube are critical for sperm selection, sperm survival, and maintenance of sperm fertilizing capacity.Results: This review will provide a comprehensive overview of the latest findings regarding sperm transport and behavior of sperm within the oviduct, sperm selection in the oviduct, the formation of the sperm reservoir, and the release of sperm in the presence of the oocyte. It will primarily focus on recent novel insights on sperm-oviduct interactions, which have been obtained by cutting-edge technologies under in vivo or near in vivo conditions. Conclusions:The comprehensive analysis of the findings to date will elucidate the complex molecular changes in the tubal epithelium, which are induced by the presence of the sperm and will highlight how the epithelial cells of this organ affect transport, behavior, and function of sperm. This knowledge is essential for scientists and clinicians involved in assisted reproductive technologies.

Sperm selection by the oviduct: perspectives for male fertility and assisted reproductive technologies

“…In the same study, transmission electron microscopy of the OECs after sperm incubation revealed an active endoplasmic reticulum in ciliated and secretory oviduct cells, which suggests an increase in protein synthesis and trafficking [98]. As discussed by Kölle [99], the oviduct may also respond to sperm interaction with the secretion of nutrients that would support sperm viability.…”

Cystic ovary disease (COD) alters structure and function of the bovine oviduct

“…The term contralateral refers to the oviduct that is on the opposite side of the reproductive tract to ovulation/COD. The ampulla was selected for investigation because this part of the oviduct is the site of sperm binding, fertilization and the first embryo-maternal communication (Kölle et al, 2009(Kölle et al, , 2020Kölle, 2022).…”

“…Overall, the percentage of motile, immotile, and hyperactivated sperm did not significantly differ in ampullae from cows with FC and LC (p = 0.14, two-way ANOVA with Tukey's multiple comparisons test) (Figure 9e). This study is the first to elucidate the impact of COD on the microarchitecture and function of the oviduct, which is the site of formation of the sperm reservoir, fertilization and early embryonic development and plays a key role in fertility (Kölle et al, 2009(Kölle et al, , 2020Kölle, 2022). Our previous studies (Scully et al, 2021) have already shown that COD impacts the transport function of the oviduct, highlighting the importance of investigating the effects of COD on all reproductive organs in addition to the existing studies of the ovarian anatomical features associated with COD and its effects on ovarian function (Borş & Borş, 2020;Gareis et al, 2023).…”

“…Overall, our results demonstrate that COD alters tubal secretory patterns in a cyst-specific way which might be associated with distinctive changes in the tubal microenvironment and its subsequent ability to support the formation of the sperm reservoir, fertilization, and embryo survival and development. Regarding the formation of the sperm reservoir, which is characterized by tangential binding of the sperm head to the cilia of the oviductal cells and allows bovine sperm to maintain fertilizing capacity for 3-4 days (Kölle, 2022), we applied live cell imaging of the sperm within the oviduct to analyze whether the altered glycoprotein metabolism and the altered epithelial cells in LC cows affect motility and survival time of the sperm within the tube. Interestingly, sperm parameters were similar to sperm in control cows suggesting that-as sperm can bind all across the oviduct, both in isthmus and ampulla (Kölle, 2022)-the reduced glycoprotein synthesis in LC cows are still sufficient to maintain sperm motility and sperm survival.…”

Deletion of the Sodium Glucose Cotransporter 1 (Sglt‐1) impairs mouse sperm movement

“…Before ejaculation, sperm are stored in a quiescent state within the cauda epididymis (De Jonge, 2005). Once deposited into the female genital tract, sperm undergo a series of biochemical and physiological changes, known as capacitation, that lead to their acquisition of fertilizing competency (De Jonge, 2017; Kölle, 2022; Puga Molina et al, 2018). Increases in extracellular Ca 2+ , HCO 3 − , and albumin initiate a signaling cascade that results in the production of cAMP, activation of protein kinases, and protein phosphorylation (Krapf et al, 2010; Puga Molina et al, 2018; Visconti et al, 2002).…”