title: Production of offspring from one-day-old oocytes stored at room temperature.
abstract: To determine the feasibility of preserving oocytes without freezing, we stored mouse oocytes in several media at different temperatures for one day. Confocal microscopy of the metaphase-II spindle in these stored oocytes revealed gross abnormalities in both the spindle and the arrangement of chromosomes. The abnormal spindles could not be rescued by transplanting the aged spindle-chromosome complex into a fresh enucleated oocyte. A diploid parthenogenetic development showed that some of the oocytes stored at room temperature could still develop into blastocysts (10-57%). However, oocytes stored in a refrigerator (5%) or incubator (0%) lost the potential almost entirely. Fertilization of room-temperature-preserved oocytes with fresh spermatozoa by ICSI or IVF resulted in, respectively, 4 and 10%, full-term births. These results suggest that when oocytes are stored at room temperature for one day, most have irreversible damage not only to their cytoplasm but also to the spindle. However, since at least a few percent of stored oocytes retained the potential for full-term development, it may be possible to overcome these problems and develop a simple method for preserving mammalian oocytes without freezing.
authors.affiliation: Laboratory for Genomic Reprogramming, Center for Developmental Biology, RIKEN, Kobe, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Wakayama
authors.forename: Nguyen Van
authors.initials: NV
authors.lastname: Thuan
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kishigami
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohta
authors.forename: Eiji
authors.initials: E
authors.lastname: Mizutani
authors.forename: Takafusa
authors.initials: T
authors.lastname: Hikichi
authors.forename: Masashi
authors.initials: M
authors.lastname: Miyake
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Wakayama
mesh_terms: D000818:Animals; D002875:Chromosomes / Q000648:ultrastructure; D003593:Cytoplasm / Q000378:metabolism; D046149:Embryo Culture Techniques / Q000379:methods*; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D018613:Microscopy, Confocal; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism; D011309:Preservation, Biological / Q000379:methods*; D013048:Specimen Handling; D020554:Sperm Injections, Intracytoplasmic; D013094:Spermatozoa / Q000166:cytology; D008941:Spindle Apparatus / Q000378:metabolism; D013696:Temperature; D013997:Time Factors