title: Dynamic quantification of intracellular calcium and protein tyrosine phosphorylation in cryopreserved boar spermatozoa during short-time incubation with oviductal fluid.
abstract: Freshly ejaculated boar spermatozoa require several hours of exposure to capacitating conditions to undergo capacitation. We hypothesized that cryopreserved boar spermatozoa might elicit a capacitation response after a relatively shorter time of exposure to capacitating conditions. Washed, frozen-thawed boar spermatozoa were incubated separately with pre-ovulatory isthmic oviductal fluid (EODF), post-ovulatory ODF (MODF), capacitation medium (CM), and noncapacitating medium (NCM) for 60 minutes. Aliquots of spermatozoa were taken at 0, 5, 15, 30, and 60 minutes during incubation and sperm kinematics, intracellular calcium [Ca2(+)]i content, and protein tyrosine phosphorylation (PTP) were studied. The proportion of motile spermatozoa increased significantly after 5 minutes of incubation with EODF. A similar increase was not observed in the other groups. During the initial 5 minutes of incubation, the proportion of spermatozoa with high [Ca(2+)]i decreased significantly in all four groups. The proportion of tyrosine phosphorylated spermatozoa increased from 6.49 ± 1.93% to 15.42 ± 3.58% and 18.41 ± 1.57% in EODF and MODF groups, respectively, at 5 minutes of incubation. Neither CM nor NCM elicited any immediate effect on PTP in spermatozoa. There was a positive and significant correlation between [Ca(2+)]i and sperm motility (P = 0.009). It may be concluded that frozen-thawed boar spermatozoa undergo capacitation-associated changes after a relatively short exposure to EODF, and there are some subpopulations of spermatozoa that undergo PTP despite possessing low [Ca(2+)]i.
authors.affiliation: Division of Reproduction, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden; Cattle Yard, Theriogenology Lab, National Dairy Research Institute, Karnal, Haryana, India.
authors.forename: A
authors.initials: A
authors.lastname: Kumaresan
authors.affiliation: Division of Reproduction, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden; Comparative Medicine and Experimental Medicine (CBEM), Veterinary Medicine, University of Calgary, Calgary, Canada.
authors.forename: R
authors.initials: R
authors.lastname: González
authors.affiliation: Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Johannisson
authors.affiliation: Division of Reproduction, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden. Electronic address: ann-sofi.bergqvist@slu.se.
authors.forename: A-S
authors.initials: AS
authors.lastname: Berqvist
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000502:physiology; D002118:Calcium / Q000032:analysis*; D015925:Cryopreservation / Q000662:veterinary; D005187:Fallopian Tubes / Q000502:physiology*; D005260:Female; D008297:Male; D010766:Phosphorylation; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013075:Sperm Capacitation / Q000502:physiology; D013081:Sperm Motility; D013094:Spermatozoa / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D034421:Sus scrofa; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D014443:Tyrosine; D002118:Calcium
keywords: Flow cytometry; Porcine sperm; Protein tyrosine phosphorylation; Tubal fluid