title: Spindle and chromosome changes of human MII oocytes during incubation after slow freezing/fast thawing procedures.
abstract: This experiment investigated the optimal time required for cryopreserved human oocytes to reform their spindles upon re-warming. Metaphase II oocytes were cryopreserved with a slow freezing method. Oocytes from each patient were randomly allocated into one of the 3 groups with different culture periods: 1, 3, or 5 hours, respectively, after thawing. Tubulin and chromosome configurations were visualized by confocal microscopy after immunostainings. By morphological assessment, 87.3% oocytes survived the process of freezing and thawing. Oocytes with normal spindle configuration increased significantly after 3 or 5 hours of incubation compared to those incubated for only 1 hour ( P < 0.05). There were no differences in the chromosome configurations among the treatment groups ( P > 0.05). This experiment demonstrated that cryopreserved human oocytes need a certain minimum period of incubation time (3 h) to recover their disrupted MII spindles and this information can be used in development of human IVF protocols with frozen oocytes.
authors.affiliation: Center for Reproductive Medicine, Provincial Hospital Affiliated to Shandong University, Jinan, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Gao
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.forename: Xuan
authors.initials: X
authors.lastname: Gao
authors.forename: Jingmei
authors.initials: J
authors.lastname: Hu
authors.forename: Huijun
authors.initials: H
authors.lastname: Yang
authors.forename: Zi-Jiang
authors.initials: ZJ
authors.lastname: Chen
mesh_terms: D002877:Chromosomes, Human / Q000648:ultrastructure*; D015925:Cryopreservation / Q000379:methods*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D018386:Kinetochores / Q000648:ultrastructure; D008677:Metaphase; D018613:Microscopy, Confocal; D008870:Microtubules / Q000648:ultrastructure; D009865:Oocytes / Q000502:physiology / Q000648:ultrastructure*; D008941:Spindle Apparatus / Q000648:ultrastructure*; D013997:Time Factors