Environmental influences on seminal plasma: Molecular and functional insights

Seminal plasma is a pivotal regulator of reproductive success that contributes to fertility and fecundity beyond its traditionally recognized function as a vehicle for spermatozoa. Rich in soluble and extracellular vesicle-encased signaling molecules, seminal plasma influences sperm integrity and function, whilst simultaneously driving profound physiological changes in the female reproductive tract. These functions are broadly conserved across vertebrate and invertebrate species and help to optimize fertilization and create an immunological environment that supports implantation and fetal development. Perturbation of seminal plasma composition or ablation of its effects can affect fertility, the progression of pregnancy and even the long-term health of offspring. Given these far‑reaching effects, the responsiveness of seminal plasma composition to environmental exposures and influences has become an important focus of research. Studies across species using a variety of different physiological perturbations or environmental exposures have shown modification to the abundance and activities of soluble and extracellular vesicle-derived seminal plasma signaling molecules. Exposures to toxins, nutritional deficiency, metabolic disturbance, and infection-associated inflammation have each been shown to affect seminal plasma components with consequences for sperm function, female reproductive tract responses, embryo development, and offspring health. Collectively, these findings position seminal plasma, in addition to spermatozoa, as an important mediator of paternal environmental influences, offering a biological means through which males convey information on their physiological state to their mates and influence reproductive success across generations.