Cryopreservation of bovine blastocysts obtained by intracytoplasmic sperm injection

Keskintepe, Levent; Brackett, Benjamin G.

doi:10.1016/s0093-691x(00)00250-8

Cited by 20 publications

(19 citation statements)

References 45 publications

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“…Information regarding cryotolerance of the ICSI-derived bovine embryos is limited to a report by Keskintepe and Brackett [25]; in that study, 16 expanded blastocysts harvested on Day 7, plus 16 blastocysts that hatched after an additional 18 h of culture were exposed to a conventional freezing regimen, resulting in cryosurvival rates of 75 and 88%, respectively. In the present study, ICSI-derived, fully-expanded bovine blastocysts harvested on Days 7 or 8 had similar ability to survive the MVC vitrification with IVF-derived counterparts.…”

Section: Discussionmentioning

confidence: 99%

“…Based on differential cell staining of fresh blastocysts, we inferred that ICSI-derived expanding blastocysts and their IVF-derived counterparts were of comparable quality (in total cell number and the ICM ratio); therefore, differences in embryo quality before vitrification apparently did not account for the higher sensitivity of ICSI-derived expanding blastocysts to MVC vitrification. The relationship between the size of blastocysts and their cryotolerance has been investigated; larger blastocysts tolerated cryopreservation better than the smaller ones [9,25,29,30], with the exception of one report in cattle [3]. For speciesspecific reasons, there was opposite size-dependent cryotolerance in human [31] and horse [32] blastocysts.…”

Section: Discussionmentioning

confidence: 99%

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Vitrification of ICSI- and IVF-derived bovine blastocysts by minimum volume cooling procedure: effect of developmental stage and age

et al. 2010

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Vitrification of ICSI- and IVF-derived bovine blastocysts by minimum volume cooling procedure: effect of developmental stage and age

et al. 2010

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“…This hypothesis is supported by the low blastocyst yields after ICSI without any exogenous activation stimuli [8,10,11,[13][14][15][16]. To improve 55 the blastocyst yields after bovine ICSI, additional exogenous activation stimuli that induce intracellular calcium spike such as direct current [19], calcium ionophore [20], ionomycin [8,13,14,16,17] or ethanol [9][10][11]15,16] have been applied. However, the monotonic calcium increase triggered by these stimuli [21,22] was insufficient to completely inactivate the MPF due to re-accumulation of the cyclin B [23] and brought the oocytes to arrest again at the M-III stage 60 [17,23,24].…”

Section: Introduction 40mentioning

confidence: 99%

A combined treatment of ionomycin with ethanol improves blastocyst development of bovine oocytes harvested from stored ovaries and microinjected with spermatozoa

et al. 2009

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Regardless of the presence of sperm-borne oocyte-activating factors, activation of bovine oocytes with exogenous activation stimuli is required for further development after intracytoplasmic sperm injection (ICSI). The present study was designed to develop a new activation regimen for improving the blastocyst yield after ICSI of bovine oocytes harvested from ovaries stored at 10-12 oC for 24 h. Following ICSI, oocytes were treated with 5 μM ionomycin for 5 min, 7% ethanol for 5 or 10 min, ionomycin followed by ethanol (5 or 10 min), ionomycin followed by 10 µg/mL Cycloheximide for 5 h, or ionomycin followed by 1.9 mM 6-dimethylaminopurine for 3 h. Across the activation regimens, the cleavage rates of ICSI oocytes (45-77%) were higher than those of parthenogenetically activated oocytes (11-21%; P<0.05). Activating the ICSI oocytes with ionomycin plus ethanol improved the blastocyst yield (29-30%) comparing to the non-treated oocytes (12%; P<0.05) but the other regimens did not (9-18%; P>0.05). The higher blastocyst yields were due to increasing the proportion of ICSI oocytes that passed through the early postfertilization events until cleavage. None of the regimens have any adverse effect on the quality of the blastocysts regarding the total cell number or the proportion of the inner cell mass cells. Thus, a new activation regimen composed from two triggers for single calcium increase has been proven effective to improve the blastocyst yield after bovine ICSI using oocytes harvested from stored ovaries.Dear Dr. John P. Kastelic, Thank you very much for prompt reply and accepting our manuscript for publication in Theriogenology. We have replied for each comment from Co-editor and the reviewer-2 in pointby-point basis.Sincerely yours, Shinichi Hochi (Corresponding author)Hany Abdalla (First author)Co-editor 1-P value has been added to the Abstract (Lines 27,29).2-The number of the references in Introduction section has been reduced. Reviewer #21-Regarding omitting the two groups (5 min ethanol group and ionomycin followed by 5 min ethanol group); We do not think that the presence of these two groups causes any difficulty to recognize the superiority of ionomycin and ethanol combination. Since activation of 7% ethanol for 5 min 4 hr after ICSI is a commonly applied method for bovine ICSI, presence of such group must be important to declare the superiority of the new combination (ionomycin and ethanol) over the methods of ethanol alone under the same experimental circumstance regarding oocyte quality, injection skill, culture condition, and so on. For the ionomycin followed by 5 min ethanol, the efficiency of this method to improve the cleavage and the blastocyst yield was similar to that of ionomycin followed by 10 min ethanol, making it possible to choose the method in which oocytes are exposed to minimum exogenous stimuli. Tables 1 and 2. 2-The time of 2 nd polar body detection has been added in footnote of 15Running head: Bovine oocyte activation after ICSI * Manuscript 2 AbstractRegardless of the pres...

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“…To overcome this problem, bovine ICSI oocytes have been treated to induce intracellular calcium spike with a direct current pulse(s) (Hwang et al 2000), calcium ionophore (Keskintepe & Brackett 2000), ionomycin (Rho et al 1998; Galli et al 2003; Oikawa et al 2005; Abdalla et al 2009) or ethanol (Horiuchi et al 2002; Oikawa et al 2005; Abdalla et al 2009). Because these stimuli do not induce long‐lasting oscillations, they have been combined with other chemicals, such as cycloheximide (Galli et al 2003) or 6‐dimethylaminopurine (Rho et al 1998; Oikawa et al 2005) that interfere with either the re‐synthesis or the activation of the metaphase‐promoting factor (MPF), respectively.…”

Section: Chemical Treatment In Bovine Icsimentioning

confidence: 99%

Microtubule assembly crucial to bovine embryonic development in assisted reproductive technologies

Hochi

2016

Animal Science Journal

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Centrosome integrity and microtubule network are crucial to the events around fertilization, including pronuclear development, migration and fusion, and the first mitotic division. The present review highlights the importance of bull spermatozoal centrosomes to function as a microtubule‐organizing center for successful fertilization and the subsequent embryonic development. Spermatozoal centrosomes need to be blended with ooplasmic pericentriolar materials accurately to nucleate and organize the sperm aster. Dysfunction of the spermatozoal centrosomes is associated with fertilization failure, which has been overcome with supplemental stimuli for oocyte activation following intracytoplasmic sperm injection in humans. Even though the spermatozoal centrosomes are functionally intact, abnormal sperm aster formation was frequently observed in vitrified‐warmed bovine oocytes, with delayed pronuclear development and migration. Treatment of the post‐warm oocytes with Rho‐associated coiled‐coil kinase inhibitor or α‐tocopherol inhibited the incidence of the abnormal aster formation, resulting in higher blastocyst yields following in vitro fertilization and culture. Thus, understanding of centrosomal function made it possible to improve the performance of advanced reproductive technologies.

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Cryopreservation of bovine blastocysts obtained by intracytoplasmic sperm injection

Cited by 20 publications

References 45 publications

Vitrification of ICSI- and IVF-derived bovine blastocysts by minimum volume cooling procedure: effect of developmental stage and age

Vitrification of ICSI- and IVF-derived bovine blastocysts by minimum volume cooling procedure: effect of developmental stage and age

A combined treatment of ionomycin with ethanol improves blastocyst development of bovine oocytes harvested from stored ovaries and microinjected with spermatozoa

Microtubule assembly crucial to bovine embryonic development in assisted reproductive technologies

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