title: Seminal plasma aids the survival and cervical transit of epididymal ram spermatozoa.
abstract: Seminal plasma purportedly plays a critical role in reproduction, but epididymal spermatozoa are capable of fertilisation following deposition in the uterus, calling into question the biological requirement of this substance. Through a combination of direct observation of spermatozoa in utero using probe-based Confocal Laser Endomicroscopy, in vivo assessment of sperm fertility and in vitro analysis of various sperm functional parameters, this study investigated the role of seminal plasma in spermatozoa transit through the cervix of the ewe. Following deposition in the cervical os, epididymal spermatozoa previously exposed to seminal plasma displayed an enhanced ability to traverse the cervix as evidenced by both significantly higher pregnancy rates and numbers of spermatozoa observed at the utero-tubal junction when compared with epididymal spermatozoa not previously exposed to seminal plasma. The beneficial effect of seminal plasma on sperm transport was clearly localised to transit through the cervix as pregnancy rates of spermatozoa deposited directly into the uterus were unaffected by exposure to seminal plasma. This phenomenon was not explained by changes to sperm motion characteristics, as seminal plasma had no effect on the motility, kinematic parameters or mitochondrial membrane potential of spermatozoa. Rather, in vitro testing revealed that seminal plasma improved the ability of epididymal spermatozoa to penetrate cervical mucus recovered from ewes in oestrus. These results demonstrate that the survival and transport of ram spermatozoa through the cervix of the ewe is not linked to their motility or velocity but rather the presence of some cervical penetration trait conferred by exposure to seminal plasma.
authors.affiliation: Faculty of Veterinary ScienceThe University of Sydney, RMC Gunn Building (B19) Regimental Drive, Sydney, New South Wales 2006, AustraliaUMR 85 INRACNRS-Université de Tours-Haras Nationaux, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, F-37380 Nouzilly, FranceFaculty of MedicineThe University of Sydney, Sydney, Australia jessica.rickard@sydney.edu.au.
authors.forename: J P
authors.initials: JP
authors.lastname: Rickard
authors.affiliation: Faculty of Veterinary ScienceThe University of Sydney, RMC Gunn Building (B19) Regimental Drive, Sydney, New South Wales 2006, AustraliaUMR 85 INRACNRS-Université de Tours-Haras Nationaux, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, F-37380 Nouzilly, FranceFaculty of MedicineThe University of Sydney, Sydney, Australia.
authors.forename: T
authors.initials: T
authors.lastname: Pini
authors.affiliation: Faculty of Veterinary ScienceThe University of Sydney, RMC Gunn Building (B19) Regimental Drive, Sydney, New South Wales 2006, AustraliaUMR 85 INRACNRS-Université de Tours-Haras Nationaux, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, F-37380 Nouzilly, FranceFaculty of MedicineThe University of Sydney, Sydney, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Soleilhavoup
authors.affiliation: Faculty of Veterinary ScienceThe University of Sydney, RMC Gunn Building (B19) Regimental Drive, Sydney, New South Wales 2006, AustraliaUMR 85 INRACNRS-Université de Tours-Haras Nationaux, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, F-37380 Nouzilly, FranceFaculty of MedicineThe University of Sydney, Sydney, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Cognie
authors.affiliation: Faculty of Veterinary ScienceThe University of Sydney, RMC Gunn Building (B19) Regimental Drive, Sydney, New South Wales 2006, AustraliaUMR 85 INRACNRS-Université de Tours-Haras Nationaux, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, F-37380 Nouzilly, FranceFaculty of MedicineThe University of Sydney, Sydney, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Bathgate
authors.affiliation: Faculty of Veterinary ScienceThe University of Sydney, RMC Gunn Building (B19) Regimental Drive, Sydney, New South Wales 2006, AustraliaUMR 85 INRACNRS-Université de Tours-Haras Nationaux, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, F-37380 Nouzilly, FranceFaculty of MedicineThe University of Sydney, Sydney, Australia Faculty of Veterinary ScienceThe University of Sydney, RMC Gunn Building (B19) Regimental Drive, Sydney, New South Wales 2006, AustraliaUMR 85 INRACNRS-Université de Tours-Haras Nationaux, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, F-37380 Nouzilly, FranceFaculty of MedicineThe University of Sydney, Sydney, Australia.
authors.forename: G W
authors.initials: GW
authors.lastname: Lynch
authors.affiliation: Faculty of Veterinary ScienceThe University of Sydney, RMC Gunn Building (B19) Regimental Drive, Sydney, New South Wales 2006, AustraliaUMR 85 INRACNRS-Université de Tours-Haras Nationaux, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, F-37380 Nouzilly, FranceFaculty of MedicineThe University of Sydney, Sydney, Australia.
authors.forename: G
authors.initials: G
authors.lastname: Evans
authors.affiliation: Faculty of Veterinary ScienceThe University of Sydney, RMC Gunn Building (B19) Regimental Drive, Sydney, New South Wales 2006, AustraliaUMR 85 INRACNRS-Université de Tours-Haras Nationaux, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, F-37380 Nouzilly, FranceFaculty of MedicineThe University of Sydney, Sydney, Australia.
authors.forename: W M C
authors.initials: WM
authors.lastname: Maxwell
authors.affiliation: Faculty of Veterinary ScienceThe University of Sydney, RMC Gunn Building (B19) Regimental Drive, Sydney, New South Wales 2006, AustraliaUMR 85 INRACNRS-Université de Tours-Haras Nationaux, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, F-37380 Nouzilly, FranceFaculty of MedicineThe University of Sydney, Sydney, Australia.
authors.forename: X
authors.initials: X
authors.lastname: Druart
authors.affiliation: Faculty of Veterinary ScienceThe University of Sydney, RMC Gunn Building (B19) Regimental Drive, Sydney, New South Wales 2006, AustraliaUMR 85 INRACNRS-Université de Tours-Haras Nationaux, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, F-37380 Nouzilly, FranceFaculty of MedicineThe University of Sydney, Sydney, Australia.
authors.forename: S P
authors.initials: SP
authors.lastname: de Graaf
mesh_terms: D000818:Animals; D002465:Cell Movement; D002470:Cell Survival; D002582:Cervix Mucus / Q000502:physiology*; D002584:Cervix Uteri / Q000502:physiology*; D004822:Epididymis / Q000166:cytology*; D005260:Female; D005298:Fertility; D007315:Insemination, Artificial; D007700:Kinetics; D008297:Male; D053078:Membrane Potential, Mitochondrial; D018613:Microscopy, Confocal; D011247:Pregnancy; D018873:Pregnancy Rate; D012661:Semen / Q000502:physiology*; D012756:Sheep; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology*; D013997:Time Factors