title: Applications of cryopreserved unfertilized mouse oocytes for in vitro fertilization.
abstract: Since the first successful reports into oocyte freezing, many papers concerning the cryopreservation of mouse oocytes have been published. However, a simple and practical cryopreservation method for unfertilized C57BL/6 mouse oocytes, and an IVF system using these cryopreserved oocytes have yet to be established, in spite of the fact that C57BL/6 is the prevalent inbred strain and is used for large-scale knockout programs. In this study, unfertilized C57BL/6 mouse oocytes were cryopreserved via a simple vitrification method. After warming, IVF was performed using cryopreserved unfertilized oocytes and fresh sperm, cryopreserved unfertilized oocytes and cold-stored sperm, cryopreserved unfertilized oocytes and frozen sperm (C57BL/6 strain sperm), and cryopreserved unfertilized oocytes and frozen sperm derived from GEM strains (C57BL/6 background GEM strains). Nearly all of the cryopreserved oocytes were recovered, of which over 90% were morphologically normal. Those oocytes were then used for in vitro fertilization, resulting in 72-97% of oocytes developing into 2-cell embryos. A portion of the 2-cell embryos were transferred to recipients, resulting in live young being produced from 32-49% of the embryos. In summary, we established the simple and practical method of mouse oocyte vitrification with high survivability and developmental ability and the IVF using the vitrified-warmed oocytes with fresh, cold-stored or cryopreserved sperm with high fertility.
authors.affiliation: Division of Reproductive Engineering, Center for Animal Resources and Development (CARD), Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811, Japan. Electronic address: nakagata@kumamoto-u.ac.jp.
authors.forename: Naomi
authors.initials: N
authors.lastname: Nakagata
authors.forename: Toru
authors.initials: T
authors.lastname: Takeo
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Fukumoto
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kondo
authors.forename: Yukie
authors.initials: Y
authors.lastname: Haruguchi
authors.forename: Yumi
authors.initials: Y
authors.lastname: Takeshita
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nakamuta
authors.forename: Hiroko
authors.initials: H
authors.lastname: Matsunaga
authors.forename: Shuuji
authors.initials: S
authors.lastname: Tsuchiyama
authors.forename: Yuta
authors.initials: Y
authors.lastname: Ishizuka
authors.forename: Kimi
authors.initials: K
authors.lastname: Araki
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D005260:Female; D005298:Fertility; D005307:Fertilization in Vitro / Q000379:methods*; D005615:Freezing; D008297:Male; D051379:Mice / Q000196:embryology / Q000502:physiology*; D008810:Mice, Inbred C57BL; D009865:Oocytes / Q000166:cytology*; D013094:Spermatozoa / Q000166:cytology; D058989:Vitrification
keywords: Cold-stored sperm; Cryopreserved sperm; Fresh Sperm; In vitro fertilization; Mouse; Oocyte vitrification