Influence of porcine spermadhesins on the susceptibility of boar spermatozoa to high dilution.
The effect of heparin-binding and non-heparin-binding spermadhesins on the viability, motility, and mitochondrial activity of boar spermatozoa at the high dilution (300,000 sperm/ml) to which sperm are exposed during the process of sex sorting by flow cytometry was investigated. Incubation of spermatozoa with heparin-binding spermadhesins caused a time- and dose-dependent decrease in the percentage of functional spermatozoa. The percentage of viable spermatozoa incubated at 38 degrees C with heparin-binding spermadhesins diluted in PBS (1 mg/ml) dropped from 75% (0.5 h) to 4% (5 h), whereas the percentage of viable spermatozoa incubated in PBS without proteins (control) decreased from 85% (0.5 h) to 19% (5 h). Addition of non-heparin-binding PSP-I/PSP-II spermadhesin to the PBS resulted in a concentration-dependent increment of the percentage of viable cells (65% after 5-h incubation), with maximum effect at 1.5 mg/ml. The heparin-binding spermadhesins totally suppressed sperm motility and mitochondrial activity after 5 h of incubation. The same parameters of sperm incubated in the presence of 1.5 mg/ml of PSP-I/PSP-II were 50% and 58%, respectively, and the percentages of control sperm displaying motility and mitochondrial activity were 21% and 26%, respectively. Moreover, the viability, motility, and mitochondrial activity all decreased on incubation of spermatozoa with mixtures of PSP-I/PSP-II and heparin-binding spermadhesins as the concentration of the latter increased. We conclude that PSP-I/PSP-II and the heparin-binding spermadhesins exert antagonistic effects on the functionality of highly diluted boar spermatozoa. The finding that PSP-I/PSP-II contributes to maintaining sperm with high viability, motility, and mitochondrial activity for at least 5 h at physiological temperature points to its potential use as an additive for sperm preservation, specifically of highly diluted, flow-sorted spermatozoa for sex preselection.
Centurion
Fernando
F
Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad de Murcia, Murcia, Spain.
Vazquez
Juan M
JM
Calvete
Juan J
JJ
Roca
Jordi
J
Sanz
Libia
L
Parrilla
Inmaculada
I
Garcia
Eva M
EM
Martinez
Emilio A
EA
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D066298:In Vitro Techniques; D008297:Male; D008928:Mitochondria / Q000187:drug effects; D011971:Receptors, Immunologic / Q000378:metabolism; D012661:Semen / Q000166:cytology; D029589:Seminal Plasma Proteins / Q000494:pharmacology*; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects*; D013552:Swine; D013997:Time Factors
D011971:Receptors, Immunologic; D029589:Seminal Plasma Proteins; C116128:heparin-binding protein receptor; C425042:spermadhesin