Characterization of Mongrel Dog Seminal Plasma Proteins and Their Correlation with Semen Characteristics

Abstract

The objective of this study was to characterize mongrel dog seminal plasma proteins with SDS-PAGE and to determine the correlation between different proteins and semen characteristics. Ejaculate volume, sperm motility, total sperm count, live sperm percent, percentage abnormalities and membrane integrity (hypo osmotic swelling test) were assessed in 5 ejaculates of seven dogs. For each dog, seminal plasma was also pooled from five ejaculates and proteins were separated by SDS-PAGE using polyacrylamide concentration of 13% and 15% in separating gels. There was considerable variation in the semen characteristics among the ejaculates of different dogs. Total protein content of seminal plasma varied from 12.06 to 21.3 mg/ml in different dogs. The number of protein bands ranged from 10–12 in different dogs. The proteins with mol wt of 42, 33, 29, 24 and 14.0 kDa were major proteins in seminal plasma of mongrel dog and ranged from 61.3% to 74.3% in different dogs. There were differences in live sperm percent (CD 5% =21.7) and HOS positive spermatozoa (CD 5% =21.01) among different dogs. There was strong correlation between volume of semen and total sperm concentration (r=+0.87), whereas the correlation between motility vs HOST (r=+0.58) and motility vs live percent (r=+0.60) was moderate. A positive correlation was observed between concentrations of 82, 70, 24, 14 kDa proteins vs percent motility, live sperm percent and percent HOS positive spermatozoa. Our study confirmed the previous conclusion that HOS-test could also be included in routine evaluation of semen. The positive correlation of 14, 24, 70 and 82 kDa proteins with semen characteristics also inferred the role of these proteins in the fertility of mongrel dog semen, which needs to be worked out further for their role in the process of fertilization.