Participation of membrane adenylyl cyclase in heparin-induced capacitation in cryopreserved bovine spermatozoa

Viability of in vitro preserved sperm of Harris's hawk (Parabuteo unicinctus)

Harris hawks (Parabuteo unicinctus) are the raptors with more anthropogenic use, which makes it necessary to improve their reproduction either natural or assisted for sustainable use even though they are not endangered. The aim of this study was to determine fresh and thawed P. unicinctus sperm capacitation and acrosome reaction parameters as indicators of sperm viability in ejaculates of birds with injuries. A total of 30 ejaculates were analyzed as fresh and thawed samples. Basic sperm evaluations as well as in vitro acrosomal reaction capability through the presence and distribution of Ca²⁺ and N-acetylglucosamine and sialic acid using chlortetracycline and agglutinin-fluorescein isothiocyanate Triticum vulgaris were performed, respectively. Tagged samples were observed using epifluorescence microscopy. The results indicated 30.00% decrease in sperm viability following freeze-thaw, while rate of capacitated sperms (10.00%) and the percentage of sperm with acrosomal reaction (40.00%) were increased. The results of the experiment demonstrated that the post-thaw viability of the obtained sperm may be an alternative for use in artificial insemination.

In vitro sperm storage with poultry oviductal secretions

In the hen oviduct, tubules have been identified that preserve the sperm, maintaining viability for up to 15 weeks. This study aimed to evaluate the physiological status of rooster sperm when preserved in vitro with uterus vaginal junction secretions (UVJS). Males and females of the Rhode Island breed were used. Sperm aliquots were prepared using Lake extender and Lake extender with UVJS (10.00%, 30.00%, 60.00%, and 90.00%). Subsequently, a basic sperm evaluation was performed and sperm physiological status was determined through the presence and distribution of Ca²⁺ and its acrosomal reaction capability via perivitelline layer (PVL) co-incubation. It was observed that motility was decreased in sperm preserved with UVJS at 6 and 24 hr) compared to 40 min and fresh semen. The sperm decapacitation percentage was increased when preserved with UVJS at 40 min, 6 and 24 hr compared to fresh semen. The acrosomal reaction was increased in sperm co-incubated with PVL, even when preserved with UVJS. It was concluded that UVJS induced physiological changes in sperm by inducing a decapacitation process, which increased sperm viability when preserved in vitro.