Vitrification may increase the rate of chromosome misalignment in the metaphase II spindle of human mature oocytes
| Autor: | Andrea Borini, Giovanni Coticchio, David F. Albertini, Giulia Scaravelli, Alessia Gambardella, John J. Bromfield, Raffaella Sciajno |
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| Předmět: |
Adult
Fluorescent Antibody Technique Spindle Apparatus Cryopreservation Embryo Culture Techniques Andrology Cryoprotective Agents Meiosis Tubulin Microtubule Image Processing Computer-Assisted medicine Humans Vitrification Metaphase Chromosome Aberrations Chi-Square Distribution Microscopy Confocal biology Obstetrics and Gynecology Chromosome Anatomy Oocyte Staining medicine.anatomical_structure Reproductive Medicine Oocytes biology.protein Female Developmental Biology |
| Zdroj: | Scopus-Elsevier |
| Popis: | The metaphase II (MII) spindle of the human oocyte may be damaged by cryopreservation. High performance confocal microscopy was used to assess meiotic spindle and chromosome organization in oocytes after vitrification by the cryoleaf system. Three hours after retrieval, donor mature oocytes were fixed or vitrified. Vitrification was performed by equilibration in 7.5% ethylene glycol (EG) and 7.5% dimethylsulphoxide (DMSO), transfer to 15% EG, 15% DMSO and 0.5 mol/l sucrose, and loading onto cryoleaf strips. Tubulin staining was found in all survived vitrified-warmed oocytes, the majority (62.8%) of which displayed a bipolar spindle. A normal bipolar spindle configuration and equatorial chromosome alignment was observed only in a part of vitrified-warmed oocytes (32.6%). This frequency was significantly lower in comparison to fresh oocytes (59.1%). In another fraction of vitrified-warmed oocytes (30.2%), spindle bipolarity was associated to one or more non-aligned scattered chromosomes that often appeared tenuously associated with the lateral microtubules of the spindle. Furthermore, in cryopreserved oocytes with a bipolar spindle, a significantly increased pole-to-pole distance (14.9 +/- 2.3 microm) was found in comparison to the fresh control (12.4 +/- 2.6 microm) (P = 0.001). Therefore, under the conditions tested, vitrified-warmed oocytes maintain a MII spindle with a bipolar organization. However, chromosome alignment appears to be partly compromised. |
| Databáze: | OpenAIRE |
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