Assessment of 1,2-propanediol (PrOH) genotoxicity on mouse oocytes by comet assay

Effect of slow freeze versus vitrification on the oocyte: an animal model

“…One study shows that freezing procedures have effects on cellular, molecular, and cytoplasmic functions (49). Previous studies also demonstrated similar results using TUNEL, suggesting that DNA integrity may not be altered after the procedure (50,51). Different protocols result in different degrees of damage (52).…”

Oocyte cryopreservation: searching for novel improvement strategies

“…Examples of damage induced by improper cell exposure to CPAs range from removal or fusing of cellular membranes to impaired enzyme activity, altered organelle structure and function, as well as perturbed protein interactions [3,26,27]. Detrimental effects of CPA exposure on genotoxicity, even without cryopreservation, have additionally been demonstrated [8]. Even sub-lethal genotoxicity such as DNA fragmentation [60] can still cause catastrophic outcomes [25,94] Thus, as important as novel methods to improve oocyte cryopreservation are, determination of novel methods of endpoint viability assessment may also be useful in improving protocols ( Table 2).…”

Cryopreservation of equine oocytes: looking into the crystal ball

“…Mature oocytes are in the middle of the second meiotic division, the MII stage, characterised by the presence of chromosomes organised by the spindle apparatus. The latter is sensitive to several types of cryodamage, which may lead to several chromosome and DNA abnormalities in cryopreserved oocytes and can cause subsequent developmental arrest (Sterzik et al 1992;Ishida et al 1997;Berthelot-Ricou et al 2011). In contrast, in immature oocytes, microtubules are not organised in the MII spindle. Therefore, in principle, the cryopreservation of immature germinal vesicle stage oocytes bypasses the risk of chromosome aberrations because, at this stage, the chromatin is decondensed and protected by a nuclear envelope (Hinrichs et al 2005).…”