title: Behavior of Mouse Spermatozoa in the Female Reproductive Tract from Soon after Mating to the Beginning of Fertilization.
abstract: Using transgenic mice with spermatozoa expressing enhanced green fluorescent protein in their acrosome and red fluorescent protein in their midpiece mitochondria, we followed the behavior of spermatozoa within the female genital tract after natural mating. When examined 15 min after coitus, many spermatozoa were around the opening of the uterotubal junction. Spermatozoa that entered the uterotubal junction were seemingly not moving, yet they steadily migrated toward the isthmus at a speed only time-lapse video recording could demonstrate. Many spermatozoa reaching the lower isthmus were motile. The site where spermatozoa attached and detached from the isthmus epithelium shifted from the lower to the upper segment of the isthmus with time. Virtually all the live spermatozoa within the lower isthmus were acrosome intact, whereas many of the actively motile spermatozoa in the upper isthmus were acrosome reacted. As far as we could observe, all the spermatozoa we found within the lumen of the ampulla and the cumulus oophorus were acrosome reacted. Even though we saw only a very few spermatozoa within the ampulla during fertilization, all were associated with, or were already within, oocytes, indicating that mouse fertilization in vivo is extremely efficient.
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Muro
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Hasuwa
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Isotani
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Miyata
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yamagata
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Ikawa
authors.affiliation: The Institute for Biogenesis Research, Department of Anatomy and Reproductive Biology, School of Medicine, University of Hawaii, Honolulu, Hawaii.
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Yanagimachi
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka, Japan okabe@biken.osaka-u.ac.jp.
authors.forename: Masaru
authors.initials: M
authors.lastname: Okabe
mesh_terms: D020101:Acrosome Reaction; D000818:Animals; D005260:Female; D005306:Fertilization; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D010057:Oviducts; D013094:Spermatozoa / Q000502:physiology*
keywords: ampulla; isthmus; mouse; oviduct; sperm migration; uterotubal junction