title: Morphometry of boar sperm head and flagellum in semen backflow after insemination.
abstract: Once deposited in the female reproductive system, sperm begin their competition and undergo a selection to reach the site of fertilization. Little is known about the special characteristics of sperm that reach the oviduct and are able to fertilize, with even less information on the role of sperm dimension and shape in transport and fertilization. Here, we examine whether sperm morphometry could be involved in their journey within the uterus. For this purpose, sperm head dimension (length, width, area, and perimeter) and shape (shape factor, ellipticity, elongation, and regularity), and flagellum length were analyzed in the backflow at different times after insemination (0-15, 16-30, and 31-60 minutes). Sperm morphometry in the backflow was also analyzed taking into account the site of semen deposition (cervical vs. intrauterine). Finally, flagellum length was measured at the uterotubal junction. Sperm analyzed in the backflow were small (head and flagellum) with different head shapes compared with sperm observed in the dose before insemination. The site of deposition influenced head morphometry and tail size both being smaller in the backflow after cervical insemination compared with intrauterine insemination. Mean tail length of sperm collected in the backflow was smaller than that in the insemination dose and at the uterotubal junction. Overall, our results suggest that sperm size may be involved in sperm transport either because of environment or through sperm selection and competence on their way to encounter the female gamete.
authors.affiliation: Department of Physiology, Faculty of Veterinary Science, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum", University of Murcia, Murcia, Spain; Institute for Biomedical Research of Murcia (IMIB-Arrixaca), Murcia, Spain. Electronic address: fagarcia@um.es.
authors.forename: Francisco Alberto
authors.initials: FA
authors.lastname: García-Vázquez
authors.affiliation: Department of Physiology, Faculty of Veterinary Science, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum", University of Murcia, Murcia, Spain; Boehringer-Ingelheim S.A., Barcelona, Spain.
authors.forename: Iván
authors.initials: I
authors.lastname: Hernández-Caravaca
authors.affiliation: Department of Physiology, Faculty of Veterinary Science, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum", University of Murcia, Murcia, Spain.
authors.forename: Wellington
authors.initials: W
authors.lastname: Yánez-Quintana
authors.affiliation: Department of Physiology, Faculty of Veterinary Science, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum", University of Murcia, Murcia, Spain; Institute for Biomedical Research of Murcia (IMIB-Arrixaca), Murcia, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Matás
authors.affiliation: Department of Physiology, Faculty of Veterinary Science, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum", University of Murcia, Murcia, Spain; Institute for Biomedical Research of Murcia (IMIB-Arrixaca), Murcia, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Soriano-Úbeda
authors.affiliation: Institute for Biomedical Research of Murcia (IMIB-Arrixaca), Murcia, Spain; Department of Cell Biology and Histology, Faculty of Medicine, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum", University of Murcia, Murcia, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Izquierdo-Rico
mesh_terms: D000818:Animals; D005260:Female; D007315:Insemination, Artificial / Q000662:veterinary*; D008297:Male; D012661:Semen / Q000502:physiology; D013094:Spermatozoa / Q000166:cytology*; D013552:Swine / Q000502:physiology*; D013997:Time Factors
keywords: Backflow; Flagellum length; Insemination; Morphometry; Sperm; Uterus