title: Exposure of progesterone receptors on the plasma membranes of stallion spermatozoa as a parameter for prediction of fertility.
abstract: Subfertility in stallions is attributed to the inability of spermatozoa to undergo the acrosome reaction in response to progesterone. In the present study, it was assessed whether there is a correlation between stallion fertility, defined on the basis of first cycle foaling rate and first cycle 'non-return rate', and the proportion of spermatozoa with exposed progesterone receptors on their plasma membranes. Semen from Dutch Warmblood (n=10) and Friesian (n=4) stallions was analysed. Progesterone 3-(o-carboxymethyl) oxime-BSA coupled with fluorescein isothiocyanate was used as a progesterone receptor probe and ethidium homodimer was used as a supravital stain. A high correlation was observed between the proportion of spermatozoa with exposed progesterone receptors and stallion fertility (r > 0.70; P < 0.01). This result indicates that exposure of progesterone receptors is a potential parameter for predicting stallion fertility.
authors.affiliation: Department of Herd Health and Reproduction, Faculty of Veterinary Medicine, P.O. Box 80151, NL-3508 TD, Utrecht University, Utrecht, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Rathi
authors.forename: M
authors.initials: M
authors.lastname: Nielen
authors.forename: F P
authors.initials: FP
authors.lastname: Cheng
authors.forename: A
authors.initials: A
authors.lastname: van Buiten
authors.forename: B
authors.initials: B
authors.lastname: Colenbrander
mesh_terms: D020101:Acrosome Reaction / Q000502:physiology; D000818:Animals; D002462:Cell Membrane / Q000502:physiology*; D005298:Fertility / Q000502:physiology*; D006736:Horses / Q000502:physiology*; D008297:Male; D011980:Receptors, Progesterone / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology* / Q000502:physiology; D013194:Staining and Labeling / Q000662:veterinary
chemical_list: D011980:Receptors, Progesterone