title: Cauda Epididymis-Specific Beta-Defensin 126 Promotes Sperm Motility but Not Fertilizing Ability in Cattle.
abstract: Bovine beta-defensin 126 (BBD126) exhibits preferential expression for the cauda epididymis of males, where it is absorbed onto the tail and postacrosomal region of the sperm. The aim of this study was to examine the role of BBD126 in bull sperm function. Fresh and frozen-thawed semen were incubated in the presence of different capacitating agents as well as with phosphatidylinositol-specific phospholipase C. These treatments, which have been successful in releasing beta-defensin 126 from macaque sperm, proved to be ineffective in bull sperm. This finding suggests that the protein behaves in a different manner in the bovine. The lack of success in removing BBD126 led us to use corpus epididymis sperm, a model in which the protein is not present, to study its functional role. Corpus sperm were incubated with cauda epididymal fluid (CEF) in the absence or presence of BBD126 antibody or with recombinant BBD126 (rBBD126). Confocal microscopy revealed that rBBD126 binds to corpus sperm with the same pattern observed for BBD126 in cauda sperm, whereas an aberrant binding pattern is observed when sperm are subject to CEF incubation. Addition of CEF increased motility as well as the number of corpus sperm migrating through cervical mucus from estrus cows. However, it decreased the ability of sperm to fertilize in vitro matured oocytes. The presence of the antibody failed to abrogate these effects. Furthermore, when rBBD126 was added in the absence of other factors and proteins from the CEF, an increase in motility was also observed and no negative effects in fertility were seen. These results suggest that BBD126 plays a key role in the acquisition of sperm motility in the epididymis.
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Fernandez-Fuertes
authors.affiliation: Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland.
authors.forename: Fernando
authors.initials: F
authors.lastname: Narciandi
authors.affiliation: Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland.
authors.forename: Cliona
authors.initials: C
authors.lastname: O'Farrelly
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland.
authors.forename: Alan K
authors.initials: AK
authors.lastname: Kelly
authors.affiliation: Department of Life Sciences, Faculty of Science and Engineering, University of Limerick, Limerick, Ireland.
authors.forename: Sean
authors.initials: S
authors.lastname: Fair
authors.affiliation: Animal & Grassland Research and Innovation Centre, Teagasc, Grange, Co. Meath, Ireland.
authors.forename: Kieran G
authors.initials: KG
authors.lastname: Meade
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland pat.lonergan@ucd.ie.
authors.forename: Patrick
authors.initials: P
authors.lastname: Lonergan
mesh_terms: D000818:Animals; D002417:Cattle; D004822:Epididymis / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D005306:Fertilization / Q000187:drug effects / Q000502:physiology*; D059471:In Vitro Oocyte Maturation Techniques; D008297:Male; D009865:Oocytes / Q000378:metabolism; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology*; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism*; D023083:beta-Defensins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D023083:beta-Defensins
keywords: epididymis; in vitro fertilization (IVF); sperm