Cystic ovary disease impairs transport speed, smooth muscle contraction, and epithelial ion transport in the bovine oviduct

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

Cystic ovary disease (COD) is a common cause of subfertility in dairy cattle. Therefore, the aim of this study was to provide novel concepts for cyst classification and to investigate the effects of COD on tubal microarchitecture, oviductal metabolic function, and the formation of the sperm reservoir. Bovine Fallopian tubes affected by follicular cysts, follicular cysts with luteinization and luteal cysts were investigated by a variety of microscopic and histological techniques and compared to control cows in metestrus and diestrus. We defined three types of cysts involved in COD, each of which had a characteristic wall thickness, inner wall appearance and cellular pattern within the cyst aspirate. Regarding the Fallopian tube, each cyst type was associated with a characteristic morphology, specifically the microarchitecture of the folds in ampulla, epithelial cell ratios, and ciliated/secretory cell size and form. Furthermore, each cyst type showed different patterns of tubal glycoprotein and acidic mucopolysaccharide synthesis, which was highly variable as compared to the controls. Our studies are the first to characterize the effects of COD on the Fallopian tube, which promotes the establishment of novel, cyst-specific therapeutic concepts in cattle and helps gain a holistic view of the causes of subfertility in cows with COD.

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

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.