title: Impact of phase transition on the mouse oocyte spindle during vitrification.
abstract: During vitrification, the glass-like solidification is the phase-transition process from liquid to solid. Phase transition is one of the major factors suspected to affect the physiology of the oocyte, such as the structure of the meiotic spindle. Therefore, it is very important to investigate the systematic and morphological alterations of the metaphase-II spindle and chromosome arrangement during complete course of a vitrification and warming process. B6D2F1 (C57BL/6 X DBA/2) mouse oocytes were cryopreserved by minimum volume cooling (MVC) method of vitrification in a solution with 15% ethylene glycol, 15% dimethylsulphoxide and 0.5 mol/l sucrose. To examine the spindle, oocytes were fixed before, during and after vitrification and were analysed by immunocytochemistry and confocal microscopy. It was shown that spindles in all oocytes could be maintained through the vitrification and warming process, even though they were exposed to extreme temperature and two rounds of phase transition. According to the sequential observations, chromosome alignment was maintained throughout the complete course of vitrification, warming and post-warming stage. The impact of phase transition was barely detectable when the oocyte was exposed to the vitrification and warming process. The oocyte spindle was able to recover immediately after warming.
authors.affiliation: Reproductive Biology Associates, Atlanta, GA, USA.
authors.forename: Ching-Chien
authors.initials: CC
authors.lastname: Chang
authors.forename: Chih-Jen
authors.initials: CJ
authors.lastname: Lin
authors.forename: Li-Ying
authors.initials: LY
authors.lastname: Sung
authors.forename: Hilton I
authors.initials: HI
authors.lastname: Kort
authors.forename: X Cindy
authors.initials: XC
authors.lastname: Tian
authors.forename: Zsolt Peter
authors.initials: ZP
authors.lastname: Nagy
mesh_terms: D000818:Animals; D002875:Chromosomes / Q000187:drug effects; D015925:Cryopreservation; D003451:Cryoprotective Agents / Q000494:pharmacology; D005260:Female; D051379:Mice; D009865:Oocytes; D044367:Phase Transition / Q000187:drug effects*; D008941:Spindle Apparatus / Q000187:drug effects / Q000648:ultrastructure*
chemical_list: D003451:Cryoprotective Agents