Ovarian odorant-like biomolecules in promoting chemotaxis behavior of spermatozoa olfactory receptors during migration, maturation, and fertilization

Studies have shown that olfactory receptor genes are the largest in the human genome, which are significantly expressed in olfactory and non-olfactory tissues such as the reproductive systems where they perform many important biological functions. There is growing evidence that bioactive metabolites from the ovary, follicular fluid, and other parts of the female reproductive tract signal the sperm through a series of signal transduction cascades that regulate sperm migration, maturation, and fertilization processes. Several studies have highlighted the role of G-protein-coupled receptors in these cellular processes. Thus, we aimed to summarize the existing evidence describing the physiological role of most prominent exogenous and endogenous biomolecules found in the female reproductive organ in enhancing the chemotaxis behavior of spermatozoa during migration, maturation, and fertilization and also to elucidate the pathological implications of its dysfunctions and the clinical significance in human fertility. In the future, drugs and molecules can be designed to activate these receptors on sperm to facilitate fertility among infertile couples and use as contraceptives.