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Ramifications of protease-based liquefaction of camel semen on physical, kinematic and surface glyco-pattern of cryopreserved spermatozoa
- Rateb, S.A., Monaco, D., El-Bahrawy, K.A., Khalifa, M.A., Abd El-Hamid, I.S., Kamel, A.M., Accogli, G., Lacalandra, G.M., Desantis, S.
- Animal reproduction science 2019 v.208 pp. 106121
- Camelus dromedarius, acrosome, adults, assisted reproductive technologies, breeding season, bromelains, camels, cell membranes, cryopreservation, fluorescence, fucose, lectins, liquefaction, neutralization, papain, polysaccharides, semen, tail, viscosity
- The efficiency of incorporating different proteases in the diluent for reducing camel semen viscosity, and subsequent ramifications on morpho-functional and glycan surface properties of cryopreserved spermatozoa were investigated. Ejaculates (n = 48) were collected from three adult camels, Camelus dromedarius, during the breeding season (January - March). A portion of each raw ejaculate was evaluated for sperm physical and morphological traits, whereas the other portion was divided into three aliquots assigned for the following liquefaction treatments: control (untreated), 0.1 mg/mL papain or 5 U/mL bromelain. All samples were diluted with Tris-lactose diluent containing the anti-enzyme E-64 to neutralize both proteases before being processed for cryopreservation. Post-thaw physical and kinematic properties of spermatozoa were analyzed using a computer-assisted sperm analysis (CASA) system. The sperm surface glycocalyx pattern was evaluated with a panel of 14 fluorescent lectins. Although bromelain was more effective in elimination of semen viscosity, there was a negative correlation between bromelain supplementation and values for the variables: normal sperm, intact acrosome and intact sperm cell membrane. Bromelain supplementation, compared to papain-treated and control samples, was positively correlated with secondary sperm abnormalities, increased straight-line velocity (VSL, μm/s) and straightness (%) of spermatozoa. Results from the glycan analysis indicated that both proteases did not affect the N-linked glycan content of the entire sperm surface, whereas the treatment with proteases induced little change in N-acetylgalactosamine and fucose terminating glycans in the tail region of the sperm. Functional studies are needed to evaluate the sperm fertility rates of bromelain- and papain-treated semen for application in camel assisted reproductive technologies.