Electrophoretic profile of boar seminal proteins

The objective of this study was to study the electrophoretic properties of Large White Yorkshire boar seminal plasma and sperm proteins. Semen was collected from eight sexually mature breeding boars by the gloved hand method; seminal plasma proteins were precipitated by the ice-cold ethanol method while sperm proteins were isolated through the Triton X detergent extraction method. Discontinuous sodium dodecyl sulphate polyacrylamide gel electrophoresis was performed to assess the molecular weight of seminal proteins. A total of 11 protein bands with the molecular weight ranging from 14 to 200 kDa were observed in the porcine seminal plasma. Protein bands of 116–200 kDa, 66–97 kDa, 55–66 kDa and 45–55 kDa were present in all the 8 boars (100%) while protein bands of molecular weight 97–116 kDa, 36–45 kDa, 29–36 kDa, 20–29 kDa and 14–20 kDa were observed only in 50%, 12.5%, 62.5%, 25% and 25% of the boars, respectively. In the case of sperm proteins, a total of 7 bands with molecular weight ranging from 29 to 200 kDa were detected. Protein bands of molecular weight 97–116 kDa, 36–45 kDa and 29–36 kDa were observed only in 62.5%, 25% and 62.5% of the boars, respectively. Seminal plasma protein fractions such as 20–29 kDa and 14–20 kDa were not detected in sperm. In conclusion, some of the seminal protein fractions in porcine semen are similar to those reported in other animal species and their role in boar fertility needs to be studied to use them as a marker for selection of breeding boars.