Cryopreservation of donkey embryos: Comparison of embryo survival rate after in vitro culture between conventional freezing and vitrification

The production of reactive oxygen species (ROS), such as superoxide anion (O2–), hydroxyl radical (OH–), hydrogen peroxide (H2O2) and organic peroxide, is a normal process that occur in the cellular mitochondrial respiratory chain (Morado et al. 2009 Reprod. Fert. Dev. 21, 608–614). Supplementation with antioxidants during in vitro culture (IVC) appears to increase the resistance of bovine embryos to the oxidative stress, and consequently improve embryo development and cryotolerance (Rocha et al. 2011 Reprod. Fert. Dev. 23 157–158). This study was conducted to evaluate the effects of period of supplementation with intra (cysteine, CIST) or extracellular (catalase, CAT) antioxidants during IVC on embryo development and cryotolerance. Cumulus–oocyte complexes (n = 1132) were maturated for 24 h in B199 medium, at 38.5°C and 5% CO2 in air. After fertilization (Day 0), zygotes were IVC for 7 days in SOF medium (0.5% BSA + 2.5% FCS) in 7% O2, 5% CO2 e 88% N2 atmosphere, at 38.5°C. The antioxidant supplementation was performed during all of the culture period (from Day 1 to Day 7) or during the first 72 h (from Day 1 to Day 3), with 0.6 mM CIST, 100 UI CAT or without antioxidants (CONTR). The cleavage and blastocyst rates were evaluated, respectively, at 72 and 168 h post-insemination, when expanded blastocysts grade I were vitrified (n = 91) by Vitri-Ingá® protocol (Ingámed®, Maringá, PR, Brazil). Then, they were thawed and cultured for 24 h to evaluate re-expansion rates. The differences between groups were analyzed by ANOVA followed by Tukey’s test, and re-expansion rates by chi-square test (P ≤ 0.05). The cleavage and blastocyst rates were, respectively, 83.52 ± 4.52a/36.19 ± 3.21a (CONTR), 79.16 ± 4.52a/38.08 ± 3.21a (CIST Day 3), 77.74 ± 4.52a/42.09 ± 3.21a (CAT Day 3), 73.57 ± 4.05a/11.15 ± 2.87b (CIST Day 7), 71.83 ± 4.05a/15.07 ± 2.87b (CAT Day 7). The embryo re-expansion rates were 90.00%a (CONTR), 93.33%a (CIST Day 3), 75.00%a (CIST Day 7), 63.64%a (CAT Day 3) and 75.00%a (CAT Day 7). Supplementation with antioxidants for 7 days of IVC impaired embryo development, compared with addition up to Day 3 (P ≤ 0.05). However, it did not affect in vitro embryo cryotolerance (P ≥ 0.05). Supplementation with antioxidants throughout all the IVC significantly impaired blastocyst rate, probably by exerting a toxic effect leading to an arrest of embryonic development. It is believed that prolonged culture in the presence of antioxidants results in excessive reduction of ROS leading to an imbalance of the cellular redox status. It is known that ROS, particularly H2O2, act on signaling pathways involved in the cellular proliferation and differentiation, in gene expression and metabolism during embryo development. Supplementation with antioxidants up to Day 3 did not differ from CONTR, probably due to low O2 tension, and the presence of antioxidants in FBS and BSA. In conclusion, supplementation with cysteine and catalase during all of the culture period impaired embryo development, however this reduction did not affect embryo survival after vitrification. Financial support was provided by FAPESP (#2011/18257-2). The authors acknowledge Ingámed, Alta Genetics Brazil.

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47 A New Device and Method for Successful Vitrification of In Vitro-Produced Ovine Embryos

Reproduction Fertility and Development ◽

10.1071/rdv30n1ab47 ◽

2018 ◽

Vol 30 (1) ◽

pp. 163

Author(s):

S. Ledda ◽

J. M. Kelly ◽

S. K. Walker ◽

Y. Natan ◽

A. Arav

Keyword(s):

Survival Rate ◽

Embryo Transfer ◽

Blastocyst Stage ◽

Embryo Cryopreservation ◽

Control Group ◽

Hatching Rate ◽

High Survival ◽

Embryo Survival ◽

New Device

To advance the use of embryo vitrification technology in veterinary practice, we developed a system in which embryo vitrification, warming, and dilution can be performed within a straw. An in-straw embryo cryopreservation method reduces the need for equipment and technical skills and can facilitate direct embryo transfer to the uterus. This study proposes the use of a new device named “Sarah” that is designed to permit all in-straw embryo cryopreservation procedures. Ovine in vitro-produced (IVP) embryos were vitrified at either early blastocyst stage (EB, n = 65, 6 days post-IVF) or fully expanded blastocyst stage (FB, n = 168, 7 days post-IVF). The vitrification procedure using Sarah constituted a 0.25-mL straw with a capsule having 50-µm pores inserted at one end. Embryos at each stage (EB and FB) were divided into 2 subgroups and vitrified by 1 of 2 methods: (1) multi-step (MS) group-a straw containing 2 embryos was sequentially loaded vertically into 1.5-mL tubes containing 6 different vitrification solutions: 10, 20, 40, 60, 80, or 100% ES (with 100% ES being 7.5% DMSO +7.5% EG + 20% FCS in TCM-199; 90 s each step) followed by 30 s each in 75 and 100% VS (100% VS being 18% DMSO +18% EG + 0.5 M trehalose + BSA in TCM-199); and (2) two-step (TS) group-the straw (2 embryos/straw) was loaded with 100% of ES (5 min), followed by 100% VS solution for 30 s. For both methods, at the end of the preparation steps, the straws were plunged directly into liquid N2. Non-vitrified embryos were maintained in in vitro culture as a control group (n = 102). The warming procedure consisted of placing the straws directly into 5-mL tubes containing 100, 50, 25% WS (WS = 1 M sucrose in TCM-199+ 20% FCS) at 38.6°C (for first solution) and at room temperature for all the rest (5 min each), before being placed into the holding medium. Embryos were recovered from the straws, incubated at 38.6 C in 5% CO2 in air in TCM 199 + 5% FCS, and evaluated for blastocoel re-expansion, embryo survival, and hatching rate at 2, 14, 48 h post-warming. Blastocyst re-expansion (2 h) after warming increased as the developmental stage progressed and was not affected by the vitrification method. In fact, it was significantly (P < 0.05) higher for FB vitrified in the MS and TS methods (77.90% and 71.25%, respectively) compared with the EB method (62.5% and 48.50%, respectively). At 24 h, survival rate of vitrified FB was significantly higher (P < 0.05) in the MS system (95.35%) compared with those in TS (86.25%). Survival rates of FB embryos for both methods (MS and TS) were significantly higher (P < 0.001) than EB embryos vitrified in MS (56.25%) and TS (56.55) methods. After 48 h of culture, the hatching rate for FB vitrified in the MS system (87.21%) was comparable with TS (77.5%) and control (85.3%) groups but significantly higher (P < 0.001) than vitrified EB in MS (43.75%) and TS (36.36%). In conclusion, we showed that a high survival rate of IVP embryos can be achieved by this new in-straw vitrification and warming device (“Sarah”), with hatching rates in vitro comparable with that of control fresh embryos. This method has the potential for use in direct embryo transfer in field conditions.

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DEVELOPMENT OF AN INTRODUCTION PROTOCOL FOR STRAWBERRY PLANTS INTO IN VITRO CULTURE

Bulletin of Agrarian Science ◽

10.17238/issn2587-666x.2020.5.45 ◽

2020 ◽

Vol 5 (86) ◽

pp. 45-50

Author(s):

O.V. Mazneva ◽

◽

L.V. Tashmatova ◽

T.M. Khromova ◽

V.V. Shakhov ◽

...

Keyword(s):

Survival Rate ◽

In Vitro Culture ◽

Plant Material ◽

Survival Rates ◽

Strawberry Plant ◽

Active Growth ◽

High Viability ◽

Average Survival ◽

Average Survival Rate

The research was conducted in order to develop an effective protocol for introducing strawberry plants into in vitro culture. The objects of the research were the most popular varieties of strawberries of domestic and foreign selection: Tsaritsa, Bereginya, Florence, Frida, Kimberly, etc. Mercurial preparations mertiolate at a concentration of 0.01% and sulema at a concentration of 0.1% were used as sterilizing agents. The isolation of explants was performed in several periods: the beginning of the growth was in February, active growth was in June, the decline of growth was in August. The studies have shown that the maximum aseptic cultures were obtained when processing strawberry plant material with mercurycontaining sulema preparation in the concentration of 0.1%. At the first stage of micropropagation, explants had a high viability during all periods of the isolation, the average survival rate for varieties was 74.8-80.7%. A significant influence of the genotype (varietal characteristics) on the survival rates of explants was noted. The number of explants suitable for cloning did not depend on the overall level of regeneration. Stabilization of the crop during winter introduction was much faster than in other periods. Using the winter term of the isolation of strawberry explants allowed to increase the yield of explants capable of further cloning, accelerate the stabilization of the culture in vitro and reduce the time for obtaining micro-plants suitable for planting in non-sterile conditions. On average, 75.2% of explants capable of further cloning for the varieties were obtained. As a result of the research, the conditions and methods for obtaining the largest number of viable sterile strawberry explants were worked out, which will be included into the process of reproduction in vitro and further research.

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In vitro comparative study of two Arundo donax L. ecotypes’ selenium tolerance

International Journal of Horticultural Science ◽

10.31421/ijhs/20/3-4/1146 ◽

2014 ◽

Vol 20 (3-4) ◽

Cited By ~ 2

Author(s):

É. Domokos-Szabolcsy ◽

N. A. Alla ◽

T. Alshaal ◽

A. Sztrik ◽

L. Márton ◽

...

Keyword(s):

Survival Rate ◽

Comparative Study ◽

In Vitro Culture ◽

Somatic Embryo ◽

Arundo Donax ◽

Sodium Selenate ◽

Inhibiting Effect ◽

Selenium Accumulation ◽

Arundo Donax L

Selenium tolerance of two somatic embryo-derived Arundo donax L. ecotypes (Blossom, 20SZ) were compared in in vitro culture. Sodium-selenate (1 – 100 mg L-1) as known the most phytoavailable selenium form and the less studied red elemental nanoselenium (100 mg L-1) were applied as selenium treatments. Basis on the results Blossom ecotype seemed to be more sensitive to the sodium-selenate than 20SZ. Inhibiting effect of selenate was effectuated above 10 mg L-1 in case of Blossom, which was manifested in decreased survival rate and growing parameters. Contrast to this 20SZ could tolerate the selenate ≤ 20 mg L-1 without any toxic symptoms. Lower selenate tolerance of Blossom could be explained with higher selenium accumulation. Both of two ecotypes could also uptake and accumulate the red elemental nanoselenium however in much less extent compared to selenate.

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High in vitro survival rate of sheep in vitro produced blastocysts vitrified with a new method and device

Journal of Animal Science and Biotechnology ◽

10.1186/s40104-019-0390-1 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Sergio Ledda ◽

Jen M. Kelly ◽

Stefano Nieddu ◽

Daniela Bebbere ◽

Federica Ariu ◽

...

Keyword(s):

Survival Rate ◽

Survival Rates ◽

Blastocyst Stage ◽

Hatching Rate ◽

High Survival ◽

Apoptotic Cells ◽

Embryo Survival ◽

New Device ◽

In Vitro Survival

Abstract Background To advance the use of embryo vitrification in veterinary practice, we developed a system in which embryo vitrification, warming and dilution can be performed within a straw. Ovine in vitro produced embryos (IVEP) were vitrified at either early (EBs: n = 74) or fully expanded blastocyst stage (FEBs: n = 195), using a new device named “E.Vit”, composed by a 0.25-mL straw with a 50-μm pore polycarbonate grid at one end. Embryos at each stage (EBs and FEBs) were vitrified by either Two-step (TS) or Multi-step (MS; 6 different concentrations of vitrification solutions) protocol. Non-vitrified embryos (n = 102) were maintained in in vitro culture as a control. Warming consisted of placing the straws directly into 1.5 mL tubes containing a TCM-199 solution with three decreasing concentrations of sucrose. Blastocyst re-expansion, embryo survival and hatching rate were evaluated at 2, 24 and 48 h post warming. The number of apoptotic cells was determined by TUNEL assay. Results Blastocyst re-expansion (2 h) after warming was higher (P < 0.05) in FEBs group, vitrified with the MS and TS methods (77.90% and 71.25%, respectively) compared with the EBs group (MS: 59.38% and TS: 48.50%, respectively). Survival rates of vitrified FEBs after 24 h IVC were higher (P < 0.001) in both methods (MS and TS) than vitrified EBs (MS: 56.25%; TS: 42.42%) and was higher (P < 0.05) in the MS method (94.19%) compared with those in TS (83.75%). After 48 h of culture the hatching rate for FEBs vitrified in MS system (91.86%) was similar to control (91.89%), but higher than FEB TS (77.5%) and EBs vitrified in MS (37.5%) and TS (33.33%). Number of apoptotic cells were higher in EBs, irrespective of the system used, compared to FEBs. The number of apoptotic cells in FEBs vitrified with MS was comparable to the control. Conclusions A high survival rate of IVP embryos can be achieved by the new “E.Vit” device with hatching rates in vitro comparable with control fresh embryos. This method has the potential for use in direct embryo transfer in field conditions.

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114 CRYOTOP VITRIFICATION FOR IN VITRO-PRODUCED BUFFALO (BUBALUS BUBALIS) EMBRYOS

Reproduction Fertility and Development ◽

10.1071/rdv19n1ab114 ◽

2007 ◽

Vol 19 (1) ◽

pp. 174 ◽

Cited By ~ 2

Author(s):

A. De Rosa ◽

L. Attanasio ◽

L. Boccia ◽

G. Pellerano ◽

G. Campanile ◽

...

Keyword(s):

Survival Rate ◽

Liquid Nitrogen ◽

Sucrose Solution ◽

Bubalus Bubalis ◽

Thin Strip ◽

Embryo Survival ◽

Vitro Fertilization ◽

Group A ◽

Group B

The aim of this study was to compare the efficiency of different combinations of cryoprotectants for vitrification of IVP buffalo (Bubalus bubalis) embryos by the cryotop method (Kuwayama et al. 2005 RBM Online 11, 300–308). In group A, we evaluated the vitrification and warming solutions previously used to vitrify buffalo embryos in French straws (Gasparrini et al. 2001 Theriogenology 55, 307). Embryos were equilibrated in 1.4 M glycerol for 5 min and in 1.4 M glycerol and 3.6 M ethylene glycol (EG) for an additional 5 min. After being transferred into 3.4 M glycerol and 4.6 M EG for 25 s, individual embryos were picked up in an extremely small volume (<0.1 �L) of vitrification solution and placed on the top of a very fine polypropylene strip (0.4 mm wide � 20 mm long � 0.1 mm thick) attached to a hard plastic handle, kindly provided by M. Kuwayama. Each embryo was placed onto the thin strip of the Cryotop and immediately submerged into liquid nitrogen. For warming, the strip of the Cryotop was immersed directly into a 0.5 M sucrose solution; embryos were retrieved and transferred into 0.25 M sucrose for 5 min before culture in SOF medium. In group B, we examined the vitrification and warming solutions previously used for OPS vitrification of buffalo embryos (De Rosa et al. 2006 Reprod. Fertil. Dev. 18, 153). Embryos were equilibrated in 7.5% EG + 7.5% dimethyl sulfoxide (DMSO) for 3 min before transfer into 16.5% EG + 16.5% DMSO + 0.5 M sucrose. After 25 s, they were placed on the cryotop, as previously described, and submerged into liquid nitrogen. For warming, embryos were recovered into a 0.25 M sucrose solution for 1 min, transferred into 0.15 M sucrose for 5 min, and cultured in SOF. IVP buffalo embryos of excellent quality that, by Day 7 of culture (Day 0 = in vitro fertilization), had reached the blastocyst stage (n = 44 and 53 for groups A and B, respectively), over 6 replicates, were vitrified. Embryo survival rate was determined as the percentage of vitrified-warmed embryos undergoing further development during a 24-h in vitro culture period. Differences between methods were analyzed by chi-square test. A significantly higher embryo survival rate was recorded in Group B compared to Group A (67.9 vs. 43.2% respectively; P < 0.05). In conclusion, it was demonstrated that cryotop vitrification, with the combination of cryoprotectants used in group B, is a valid tool to cryopreserve IVP buffalo blastocysts.

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91 PRELIMINARY RESULTS OF SURGICAL EQUINE EMBRYO TRANSFER AFTER OPEN PULLED STRAW VITRIFICATION

Reproduction Fertility and Development ◽

10.1071/rdv18n2ab91 ◽

2006 ◽

Vol 18 (2) ◽

pp. 154 ◽

Cited By ~ 1

Author(s):

G. Duchamp ◽

F. Guignot ◽

J. Grizelj ◽

M. Vidament ◽

P. Mermillod

Keyword(s):

Calf Serum ◽

Embryo Cryopreservation ◽

Success Rates ◽

Ringer Lactate ◽

Embryo Survival ◽

Preliminary Study ◽

Higher Sensitivity ◽

Conventional Freezing

In equine species, embryo cryopreservation is not as widely developed as in some other species. Slow freezing has been applied to equine embryos but with relatively low success rates. This higher sensitivity to conventional freezing procedures may be explained by the presence of a capsule surrounding the equine embryo that may impair cryoprotectant penetration. Recently, good in vitro embryo survival rate was obtained after open pulled straw (OPS) vitrification (Moussa et al. 2005 Theriogenology 64, 1619–1632). The aim of the present study was to evaluate in vivo survival of vitrified embryos five days after surgical transfer into Welsh pony mares. Morulae (M), early blastocysts (EB), and blastocysts (B) ranging from 140 to 320 μm in diameter were collected (n = 20) in a Ringer lactate solution on Day 6.75 after ovulation. Before vitrification, embryos were assessed morphologically and their size was measured (McKinnon and Squires 1988 J. Am. Vet. Med. Assoc. 192, 401–406). Then, embryos were vitrified using the OPS method described by Berthelot et al. (2001 Reprod. Nutr. Dev. 41, 267–272). Briefly, embryos were washed twice in HEMES-TCM-199 + 20% newborn calf serum (NBCS) for 1 min, equilibrated in HEPES-TCM-199 + 20% NBCS with 7.5% dimethyl sulfoxide (DMSO) + 7.5% ethylene glycol (EG) for 3 min, and then with 18% DMSO + 18% EG + 0.4 M sucrose for 45 s. One embryo was then loaded per straw. For transfer, four straws were quickly thawed (5 s in air) and the narrow end of the straw containing the embryo was immersed in HEPES-TCM-199 + 20% NBCS + PBS + 0.2 M sucrose. Five to 8 min after thawing, four embryos were surgically transferred into the cranial portion of the uterine horn in each of five pony mare recipients. Five days after transfer, embryos recovered by transcervical flushing of the uterus were classified as viable if morphology was normal, no dark inner cells were present, the capsule was intact, and the diameter was at least 1000 μm. The results are shown in the table. One recipient of vitrified embryos had an endometritis and no embryo was recovered. From the four other recipients, nine embryos were recovered out of 16 (56%) transferred, seven of which were viable (44%). The results of the present preliminary study demonstrating survival of equine embryos transferred after OPS vitrification is very encouraging. However, the results should be confirmed by birth of foals after transfer of OPS-vitrified embryos to recipients. Table

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In Vitro Regeneration of Tea (Camellia sinensis (L). O. Kuntze) By Somatic Embryogenesis from Immature Cotyledon Tissues

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v9isp.2587-2590.4940 ◽

2022 ◽

Vol 9 (sp) ◽

pp. 2587-2590

Author(s):

Emine Yurteri ◽

Mücahit Salih Can ◽

Fatih Seyis ◽

Haydar Kuplemez

Keyword(s):

Somatic Embryogenesis ◽

Survival Rate ◽

Camellia Sinensis ◽

In Vitro Regeneration ◽

Phenylboronic Acid ◽

Control Group ◽

Ms Medium ◽

Embryo Survival ◽

Regeneration Rate

Tea (Camellia sinensis) is the world's most popular beverage plant, as well as an important plantation crop with high commercial value. It has been maintained for centuries through conventional vegetative propagation. Tea clonal propagation in vitro has the advantage of producing a large number of elite plants. If an efficient in vitro regeneration technology is available, this technique could be exploited for selection of tea plants for desired trait. The selected plants could be later on multiplied through in vitro or ex vitro techniques. The study aimed to induced somatic embryogenesis from immature embryo explants to genetic variaton. Different concentrations of phenylboronic acid with benzyladenine and phenylboronic acid with kinetin were tested in MS medium with 30 g/L sucrose and 8 g/L agar. MS medium without any plant growth regulators was used as control group. Considering the embryo survival rate, 1.5 mg/ L-1 phenylboronic acid + 1 mg/ L-1 kinetin produced highest result as 87.3% while lowest was in control group as 36.7%. The highest plant regeneration rate was found in 1,5 mg/ L-1 phenylboronic acid + 1 mg/ L-1 kinetin and 1.5 mg/ L-1 phenylboronic acid + 1 mg/ L-1 benzyladenine medium respectively as 58.3% and 55.6%. Kinetin treatment with increasing phenylboronic acid concentrations gave the best results in terms of somatic embryo survival rate. Also, kinetin treatment produced better results when compared to benzyladenine concentrations.

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125 IN VITRO-PRODUCED BOVINE EMBRYOS VITRIFIED IN GLASS CAPILLARIES USING TCM-199 OR DULBECCO'S PHOSPHATE-BUFFERED SALINE AS VITRIFICATION-WARMING MEDIA

Reproduction Fertility and Development ◽

10.1071/rdv19n1ab125 ◽

2007 ◽

Vol 19 (1) ◽

pp. 180 ◽

Cited By ~ 1

Author(s):

N. Mucci ◽

G. G. Kaiser ◽

G. Rios ◽

R. H. Alberio ◽

L. B. Ferré ◽

...

Keyword(s):

Survival Rate ◽

Control Group ◽

Internal Diameter ◽

Hatching Rate ◽

External Diameter ◽

Low Oxygen ◽

Embryo Survival ◽

Glass Capillaries ◽

Phosphate Buffered Saline

In previous studies (unpublished data) we observed that the replacement of open pulled straws (OPS) with glass capillaries (GC) did not affect the embryo survival rate after vitrification–warming. The aim of this work was to evaluate the post-Cryopreservation survival rate of in vitro-produced bovine blastocysts (B) and expanded blastocysts (eB) using Dulbecco's phosphate-buffered saline (PBS) or TCM-199 (TCM; Sigma-Aldrich, St Louis, MO, USA) as holding medium during vitrification and warming in glass capillaries. Cumulus–oocyte complexes were in vitro-matured and fertilized as previously described (Mucci et al. 2006 Theriogenology 65, 1551–1562), and cultured in 4 well plates in groups of 50 in 400-�L drops in serum-free CR1aa under low oxygen condition. Grade B1, B2, and eB were selected at Day 7 post-insemination and allocated to 3 groups: vitrification in TCM, vitrification in PBS, and control (without vitrification). Vitrification and warming were performed according to Vajta et al. (1998, Mol. Reprod. Dev. 51, 53–58), replacing OPS with GC (Tecnon Argentina S.A., Buenos Aires, Argentina); 75 mM length, 1.4 mM internal diameter, 1.6 mM external diameter). Briefly, B and eB were incubated in 1.78 M ethylene glycol (EG) and 1.3 M dimethyl sulfoxide (DMSO) in TCM or PBS supplemented with 20% estrous cow serum (ECS) for 3 min. Embryos were then transferred for 25 s to TCM or PBS supplemented with 3.56 M EG, 2.6 M DMSO, 0.5 M sucrose, and 20% ECS (vitrification solution: VS). Loading of embryos (2 per capillary) was performed by touching a 1-�L drop of VS with the capillary. After this, each capillary was immediately submerged into and stored in liquid nitrogen. Warming was performed by placing the capillary tip directly into TCM or PBS supplemented with 0.25 M sucrose for 5 min. Embryos were then transferred to TCM or PBS containing 0.15 M sucrose and 20% ECS for 1 min. After warming, embryos were cultured for 72 h in CR1aa + 5% ECS to evaluate embryo survival (hatching rate). Data was analyzed using the CATMOD procedure (SAS Institute, Inc., Cary, NC, USA). No interaction was found between holding media and embryo stage. Vitrified-warmed embryos had a significantly lower hatching rate compared with the control group (P < 0.05), whereas no differences were found between TCM and PBS. Expanded blastocysts had a higher hatching rate than blastocysts (P < 0.05). In conclusion, TCM can be replaced with PBS for its use in vitrification procedures. This protocol modification allows a simplified use of this technique in field conditions.

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89 OPEN PULLED STRAW VITRIFICATION FOR IN VITRO-PRODUCED BUFFALO (BUBALUS BUBALIS) EMBRYOS

Reproduction Fertility and Development ◽

10.1071/rdv18n2ab89 ◽

2006 ◽

Vol 18 (2) ◽

pp. 153 ◽

Cited By ~ 6

Author(s):

A. De Rosa ◽

R. Di Palo ◽

L. Attanasio ◽

E. Monaco ◽

G. Campanile ◽

...

Keyword(s):

Survival Rate ◽

In Vitro Fertilization ◽

Developmental Stages ◽

Sucrose Solution ◽

Bubalus Bubalis ◽

Embryo Survival ◽

Vitro Fertilization ◽

Arcsine Transformation ◽

Further Development

The aim of this study was to compare the efficiency of different combinations of cryoprotectants for vitrification of IVP buffalo (Bubalus bubalis) embryos at different developmental stages by the open pulled straw (OPS) method. In method A, we evaluated the vitrification and warming solutions previously used to vitrify buffalo embryos in French straws (Gasparrini et al. 2001 Theriogenology 55, 307). Embryos were equilibrated in 1.4 M glycerol for 5 min before being placed into 1.4 M glycerol + 3.6 M ethylene glycol (EG) for 5 min. Then, embryos were transferred into 3.4 M glycerol + 4.6 M EG for 25 s and loaded into the OPSs. For warming, OPSs were briefly immersed in a 0.5 M sucrose solution; the embryos were exposed to 0.25 M sucrose for 5 min before transfer to SOF medium for culture. In Method B, we examined the vitrification and warming solutions previously used for OPS vitrification of cattle embryos (Vajta et al. 1998 Mol. Reprod. Dev. 51, 53-58). Buffalo embryos were equilibrated in 7.5% EG + 7.5% dimethyl sulfoxide (DMSO) for 3 min before transfer into 16.5% EG + 16.5% DMSO and 0.5 M sucrose. After 25 s, they were loaded into the OPSs. For warming, embryos were recovered in a 0.25 M sucrose solution and transferred into a 0.15 M sucrose solution for 5 min before being placed in SOF medium. A total of 293 IVP buffalo embryos (eight replicates) were vitrified at Day 7 of culture (Day 0 = in vitro fertilization). Embryos were vitrified at the following developmental stages: early blastocyst (eBL, n = 26 and 34 with methods A and B, respectively), blastocyst (Bl, n = 31 and 35 for Methods A and B, respectively), expanded blastocyst (XBl, n = 29 and 38 for Methods A and B, respectively), and hatched blastocyst (HBl, n = 46 and 54 for Methods A and B, respectively). Embryo survival rate was determined as the percentage of vitrified-warmed embryos undergoing further development during a 24-h in vitro culture period. Differences between methods were analyzed by ANOVA following arcsine transformation of data. The overall embryo survival rate recorded at 24 h was not significantly different between Methods A and B (70% vs. 62%, respectively). Specifically, no differences were observed in embryos vitrified at the eBL (70% vs. 73%, A and B, respectively), Bl (69% vs. 70%, A and B, respectively), and HBl (46% vs. 36%, A and B, respectively) stages. In contrast, a significantly higher survival rate was recorded for XBl-stage embryos vitrified-warmed by Method A as compared to Method B (90% vs. 53%, respectively; P < 0.01). In Method A, survival rate of XBl was significantly higher than that of HBl (P < 0.05), but it was not different from that of eBl and Bl. Within Method B, the survival efficiency was similar for eBL, BL, and XBl, whereas survival rate of HBl was significantly lower (P < 0.05). In conclusion, although overall embryo survival in vitro was similar between methods, the combination of cryoprotectants used in Method A seemed more suitable for vitrification of IVP buffalo embryos at the XBl stage.

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