Cryotops versus open-pulled straws (OPS) as carriers for the cryopreservation of bovine oocytes: Effects on spindle and chromosome configuration and embryo development

Morató, Roser; Izquierdo, Dolors; Paramio, M. T.; Mogas, T.

doi:10.1016/j.cryobiol.2008.07.003

Cited by 101 publications

(68 citation statements)

References 35 publications

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“…The achievements of vitrification with our newly developed carrier are comparable to results achieved by following research teams using similar vitrification protocol and open carriers (Luna et al 2001;Diez et al 2002;Vieira et al 2002;Modina et al 2004;Albarracín et al 2005;Morató et al 2008aMorató et al , 2008bMorató et al , 2008cand Hou et al 2009). Hence, we can declare this new carrier a safe variant for bovine oocyte vitrification, which is inexpensive to manufacture from affordable components.…”

Section: Discussionsupporting

confidence: 66%

Closed system for bovine oocyte vitrification

Ševelová

Lopatářová

2012

Acta Vet. Brno

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The aim of our study was to develop a vitrification carrier for bovine oocyte cryopreservation. The carrier was to be cheap enough, elementary in its construction and meet contemporary requirements for a safe closed system. In a closed system, a cell is prevented from direct exposure to liquid nitrogen, thus minimizing the risk of cross-contamination. Furthermore, two questions regarding the proper vitrification technique were resolved: if it is necessary to partially denude the oocytes before the vitrification process or whether intact cumulus oocyte complexes should be frozen; and if it is more advantageous to preheat the vitrification solutions to female body temperature (39 °C) or to keep them at room temperature. Our results show that it is better to partially denude the oocytes prior to vitrification because cryopreserved intact cumulus oocyte complexes often proved dark, non-homogeneous or fragmented cytoplasm after warming, with many of them having visibly widened perivitelline spaces or fractured zonae pellucidae as a result of extensive damage during vitrification. Consequently, intact cumulus oocyte complexes showed significantly lower numbers of cleavage stage embryos on Day 3 compared to partially denuded oocytes (7.4% and 26%, respectively). On the other hand, the survival rate and following development of fertilized oocytes in preheated vitrification solution were equal to results reached at room temperature conditions. In conclusion, results achieved with the newly developed carrier were comparable to previously published studies and therefore they could be recommended for common use.

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Section: Discussionsupporting

confidence: 66%

Closed system for bovine oocyte vitrification

Ševelová

Lopatářová

2012

Acta Vet. Brno

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“…The cleavage and blastocyst formation rates of bovine M-II oocytes cryopreserved by either the Cryotop and SSV methods in our study were higher than those reported by Roser et al [36] using the Cryotop method. On the other hand, the cleavage and blastocyst formation rates of surviving vitrified oocytes in both the Cryotop and SSV groups were still reduced compared with those of the Fresh control and Solution control groups.…”

Section: Discussioncontrasting

confidence: 56%

A Comparison of Cryotop and Solid Surface Vitrification Methods for the Cryopreservation of In Vitro Matured Bovine Oocytes

Sripunya

Somfai

Inaba

et al. 2010

Journal of Reproduction and Development

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Abstract. The aim of the present study was to compare the efficacies of the cooling systems of the solid surface (SSV) and Cryotop vitrification methods for cryopreservation of bovine oocytes at the metaphase II stage. The effects of vitrification on oocyte viability, in vitro fertilization (IVF), pronucleus formation and subsequent in vitro development were assessed. In vitro matured (IVM) bovine oocytes were subjected to equilibration and vitrification solutions according to the SSV method, and then the oocytes were vitrified either by dropping onto a cold dry metal surface (SSV group) or by plunging into liquid nitrogen on Cryotop sheets (Cryotop group). Warming was conducted according to the SSV method. Some oocytes were subjected to the cryoprotectants and warming regimen without cooling (Solution control group). The live/dead status of oocytes was evaluated by fluorescein diacetate staining. Live oocytes were subjected to IVF, and the resultant embryos were cultured in vitro. The rates of live oocytes were similar among the Fresh control, Solution control, SSV and Cryotop groups. There was no difference in the rates of fertilization, pronuclear formation and monospermy among these groups. The cleavage rates in the SSV and Cryotop groups (41.6 and 53.2%, respectively) were significantly lower than those in the Fresh control and Solution control groups (65.9 and 61.3%, respectively). The blastocyst rates in SSV and Cryotop groups did not differ (10.3 and 12.8%, respectively); however, they were significantly lower than those in the Fresh control and Solution control groups (36.4 and 24.8%, respectively). The inner cell mass, trophectoderm and total cell numbers in blastocysts did not differ significantly among the Fresh control, Solution control, SSV and Cryotop groups. Our results indicate that IVM bovine oocytes could be cryopreserved successfully using the cooling systems of the Cryotop and Solid Surface Vitrification methods with similar efficacy. Key words: Bovine, Cryotop, Oocyte, Solid surface vitrification, Vitrification (J. Reprod. Dev. 56: [176][177][178][179][180][181] 2010) ryopreservation of bovine oocytes is of great importance in the preservation of female genetic resources. Cryopreserved oocytes can be used for in vitro fertilization (IVF), nuclear transfer and genetic manipulation. Rall and Fahy [1] were the first to report vitrification, a glass-like solidification, by ultra-rapid cooling of mouse embryos, showing an alternative to traditional freezing methods to avoid chilling injury and ice crystal formation. Vitrification has been widely applied to cryopreserve oocytes in other mammalian species including cattle [2] In general, oocytes are more susceptible to cooling damage than zygotes because metaphase spindle microtubule integrity is disrupted during cooling and the high concentration of cryoprotectants affects oocytes during equilibration [10]. Also, differences in the membrane structures seem to make oocytes more sensitive to chilling compared with zygotes [11]. Although the tox...

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“…This technique is greatly influenced by the developmental stages of embryos, type of species and/or even the animal strain (Tsutsumi et al, 1998;Ueichi et al, 1999;Moore and Bonilla, 2006;Morato et al, 2008). As a result a thorough modification of the technique is required concerning the above factors to obtain it for the better results with minimal consequences.…”

Section: Discussionmentioning

confidence: 99%

Transcript analysis of Heat shock protein 72 and protein 53 of 4-cell mouse embryos following Cryotop vitrification

Habibi¹,

Farrokhi²,

Silva³

et al. 2013

CZECH J ANIM SCI

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ABSTRACT:The effects of two different concentrations of cryoprotectants on survival and developmental capacity of four-cell mouse embryos were compared by Cryotop vitrification to demonstrate that lower concentrations provide the same results as higher previously reported concentrations with lesser negative molecular impact on embryo cells. For this latest, embryos were compared via transcript analyses of Heat shock protein 72 (Hsp72) and protein 53 (p53). Four-cell embryos were obtained from superovulated female mice and randomly assigned to one of three following groups: (i) control (non-vitrified), (ii) vit 1 (15% v/v: 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO), and (iii) vit 2 (30% v/v: 15% EG + 15% DMSO). The cells vitrified by Cryotop were thawed and side-by-side to the control group divided into two parts: one part was used to analyze the morphological traits, survival rate, and embryo cleavage ability to form blastocysts, and the other part was examined for changes in transcript levels of Hsp72 (Hspa1a + Hspa1b), p53, and Hprt1 (reference gene) by quantitative Real-Time polymerase chain reaction (qPCR). The results were analyzed by One Way Analysis of Variance and the mean values compared with LSD (P < 0.05). The relative expression of p53 in vit 2 (30% v/v) was significantly higher than in vit 1 (15% v/v) and in vit 1 it was higher than in the control. The relative expression of Hsp72 was the same in vit 1 and vit 2 and significantly higher than in the control. The survival, cleavage, and blastocyst rates were the same for both vitrification treatments and significantly lower than in the control group. The up-regulations of Hsp72 and p53 following vitrification were suggestive of imposed heat shock, cold stress, and DNA damage to the mouse 4-cell embryos.

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Cryotops versus open-pulled straws (OPS) as carriers for the cryopreservation of bovine oocytes: Effects on spindle and chromosome configuration and embryo development

Cited by 101 publications

References 35 publications

Closed system for bovine oocyte vitrification

Closed system for bovine oocyte vitrification

A Comparison of Cryotop and Solid Surface Vitrification Methods for the Cryopreservation of In Vitro Matured Bovine Oocytes

Transcript analysis of Heat shock protein 72 and protein 53 of 4-cell mouse embryos following Cryotop vitrification

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