title: Surfing and Swimming of Ejaculated Sperm in the Mouse Oviduct.
abstract: To accomplish fertilization in the oviductal ampulla, ejaculated sperm are required to migrate through the female reproductive tract. However, this fundamental process largely remains unknown. In this study, we focused on the role of oviductal smooth muscle (myosalpinx) contractions in the sperm migration. Administration of prifinium bromide, padrin, to mice effectively suppressed myosalpinx contractions, resulting in a decreased rate of fertilization in a dose-dependent manner, and an abrogation of high-speed back-and-forth/shuttling flows of oviductal fluids around the isthmus. Regardless of padrin administration, no shuttling flows were found near the ampulla. In the isthmus, sperm formed a tight assemblage that was synchronized with the shuttling flows. The sperm assemblage was gradually loosened and then completely abolished near the ampulla. No sperm assemblage was formed in the isthmus when padrin was administrated. These results suggest that myosalpinx contractions play important roles in the formation of sperm assemblage in the isthmus, and in the transport of the assemblage to the middle region of the oviduct. It is also suggested that the motility of sperm is essential for the migration of sperm from the middle oviductal region to the ampulla.
authors.affiliation: Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan Ph.D. Program in Human Biology, School of Integrative and Global Majors, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ishikawa
authors.affiliation: Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Usui
authors.affiliation: Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan.
authors.forename: Misuzu
authors.initials: M
authors.lastname: Yamashita
authors.affiliation: Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan Ph.D. Program in Human Biology, School of Integrative and Global Majors, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kanemori
authors.affiliation: Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan Ph.D. Program in Human Biology, School of Integrative and Global Majors, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan Life Science Center of Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba Science City, Ibaraki, Japan baba.tadashi.gf@u.tsukuba.ac.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Baba
mesh_terms: D000818:Animals; D005260:Female; D005306:Fertilization; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009130:Muscle, Smooth / Q000502:physiology*; D010057:Oviducts / Q000502:physiology*; D011759:Pyrrolidines; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology*
chemical_list: D011759:Pyrrolidines; C084641:pyrodifenium bromide
keywords: female reproductive tract; fertilization; myosalpinx contractions; sperm migration