PURPOSE: Investigate the effect of vitrification on in vitro maturation (IVM) and expression of Aurora kinases A, B, and C in germinal vesicle (GV)-stage oocytes. METHODS: GV-stage oocytes from B6D2F1 female mice 7-11 weeks of age were vitrified after collection, thawed, and matured in vitro for 0, 4, 8, and 12 h (hrs). The rate of germinal vesicle breakdown (GVBD), spindle apparatus assembly, and Aurora kinase mRNA and protein expression during IVM was measured. RESULTS: Oocyte vitrification was associated with significant delays in both GVBD and normal spindle apparatus assembly at 4 and 8 h of IVM (p < 0.05). There was no difference in mRNA levels between control and vitrified oocytes for any of the Aurora kinases. Aurora A protein levels were reduced in vitrified compared to control oocytes at 0 h (p = 0.008), and there was no difference at 4 and 8 h (p = 0.08 and 0.69, respectively) of IVM. CONCLUSIONS: Vitrified oocytes have delayed GVBD and normal spindle assembly during in vitro maturation. Reduced levels of Aurora A protein immediately post-thaw may be associated with the impaired oocyte maturation manifested by the delayed progression through meiosis I and II, and the atypical timing of the formation of meiotic spindles in vitrified GV-stage oocytes.
PURPOSE: Investigate the effect of vitrification on in vitro maturation (IVM) and expression of Aurora kinases A, B, and C in germinal vesicle (GV)-stage oocytes. METHODS: GV-stage oocytes from B6D2F1 female mice 7-11 weeks of age were vitrified after collection, thawed, and matured in vitro for 0, 4, 8, and 12 h (hrs). The rate of germinal vesicle breakdown (GVBD), spindle apparatus assembly, and Aurora kinase mRNA and protein expression during IVM was measured. RESULTS: Oocyte vitrification was associated with significant delays in both GVBD and normal spindle apparatus assembly at 4 and 8 h of IVM (p < 0.05). There was no difference in mRNA levels between control and vitrified oocytes for any of the Aurora kinases. Aurora A protein levels were reduced in vitrified compared to control oocytes at 0 h (p = 0.008), and there was no difference at 4 and 8 h (p = 0.08 and 0.69, respectively) of IVM. CONCLUSIONS: Vitrified oocytes have delayed GVBD and normal spindle assembly during in vitro maturation. Reduced levels of Aurora A protein immediately post-thaw may be associated with the impaired oocyte maturation manifested by the delayed progression through meiosis I and II, and the atypical timing of the formation of meiotic spindles in vitrified GV-stage oocytes.
Authors: Karen Schindler; Olga Davydenko; Brianna Fram; Michael A Lampson; Richard M Schultz Journal: Proc Natl Acad Sci U S A Date: 2012-07-09 Impact factor: 11.205
Authors: G Coticchio; J J Bromfield; R Sciajno; A Gambardella; G Scaravelli; A Borini; D F Albertini Journal: Reprod Biomed Online Date: 2009 Impact factor: 3.828