Ovarian fluid induces molecular remodeling of sperm to enhance performance in a teleost fish
For most externally fertilizing teleost fish, sperm remain immotile until release into the external environment, where physicochemical cues trigger motility. In many species, ovarian fluid present at spawning further enhances sperm swimming performance, enabling cells to swim longer and at higher velocities than in water alone, including blue catfish (Ictalurus furcatus). This study aimed to identify molecular pathways associated with sperm-environment interactions between: (i) sperm combined with 100% ovarian fluid (inactive); (ii) sperm activated with 100% DH2O (control); and (iii) sperm activated with 25% ovarian fluid and 75% DH2O (hypermotile).