113 EVALUATION OF DIFFERENT CRYOPROTECTANT AND FORSKOLIN IN THE CULTURE MEDIUM FOR IMPROVING THE EFFICACY OF VITRIFICATION OF BOS INDICUS IN VITRO-DERIVED EMBRYOS

2010 ◽  
Vol 22 (1) ◽  
pp. 215 ◽  
Author(s):  
B. V. Sanches ◽  
B. D. O. Filho ◽  
J. H. F. Pontes ◽  
A. C. Basso ◽  
M. L. G. Meirinhos ◽  
...  

Embryo cryopreservation is an essential method for the biotechnology of reproduction. This is the safest option for interchange of genetic material for research and commercial purposes. For cattle, Brazil has become the leading country in the world for the number of in vitro-produced embryos, using mostly Bos indicus animals. However, considering the in vitro method of embryo production, field results have shown a lower resistance to cryopreservation for B. indicus when compared with Bos taurus embryos. A possible explanation for this is a great concentration of lipid droplets in the cytoplasm of cells fromB. indicus embryos. The objective of this study was to compare 2 cryoprotectants (Propanediol and DMSO) to vitrification and evaluate the effect of adding 10 μM forskolin to the SOF medium for embryo culture before cryopreservation. For all the experiments, ovaries from slaughtered Nelore Bos indicus donors were recovered and maintained at 30 to 35°C in NaCl solution until recovery of the COC. Embryos submmited to vitrification were expanded blastocysts at Day 7 of in vitro culture. In the first experiment embryos were first incubated in 10% ethylene glycol (EG) plus 10% DMSO dissolved in holding medium (TCM-HEPES with 20% calf serum) for 1 min and then transferred to droplet of 20% EG plus 20% DMSO in holding medium and 0.5 M sucrose for 20 s before immersing in liquid nitrogen (n = 107; group EG + DMSO). For the group EG + Propanediol (EG + PRO; n = 96), blastocysts were placed in 10% EG plus 10% PRO in holding medium for 1 min and then transferred to a droplet of 20% EG plus 20% PRO in holding medium and 0.5 M sucrose for 20 s before immersing in liquid nitrogen. Both treatments were performed using the Cryotop system. Results were compared with embryos (n = 118) not submitted to cryopreservation. The evaluation was done by the hatching rate of blastocysts at Day 9, being higher (86.4%) for embryos not cryopreserved, when comparing with 77.1% for group EG + PRO and 72.9% for group EG + DMSO (P < 0.05). In the second experiment, Day 5 embryos obtained in vitro from Nelore donors were cultured using SOF medium with 10 μM forskolin (n = 112) or not (control; n = 101), being all submitted to cryopreservation using Cryotop and the same vitrification method for group EG + DMSO. Results were compared with embryos cultured with SOF medium and not submitted to cryopreservation (n = 96). The evaluation was performed by considering hatching rate at Day 9, being higher (85.4%) for not cryopreserved, when compared with 63.3% for control and 70.5% for forskolin group (P < 0.05). Considering embryos submitted to cryopreservation, the hatching rate was higher (P < 0.05) for the forskolin group.

2006 ◽  
Vol 18 (2) ◽  
pp. 188
Author(s):  
F. George ◽  
C. Daniaux ◽  
G. Genicot ◽  
F. Focant ◽  
B. Verhaeghe ◽  
...  

In vitro-produced (IVP) bovine blastocysts are known to be more sensitive to cryopreservation than their in vivo counterparts. Removing serum from the culture medium decreases sanitary risk and could improve embryo resistance to cryopreservation by preventing the accumulation of intracellular lipids. Our objectives were to evaluate the lipid content, resistance to cryopreservation, and sex ratio of IVP embryos cultured in a serum-free system. Oocytes from slaughterhouse ovaries were matured in a serum-free enriched medium (Donnay et al. 2004 Reprod. Fertil. Dev. 16, 274) and cultured in 5% O2 in modified SOF supplemented with 5% FCS (FCS) or with insulin-transferrin-selenium (ITS) and 0.1 mg/mL polyvinylpyrrolidone (PVP) (ITS-PVP) or 4 mg/mL BSA (ITS-BSA) (Daniaux et al. 2005 Reprod. Fertil. Dev. 17, 217). Day 5 morulae were stained with the fluorescent dye Nile Red in order to evaluate their lipid content (Genicot et al. 2005 Theriogenology 63, 1181). Day 7 blastocysts (diameter ≥160 µm) were selected, classified according to their size, and frozen in HEPES-SOF containing 1.5 M ethylene glycol, 0.1 M sucrose, and 1.8 mg/mL wheat peptones (George et al. 2002 Reproduction 29, 51). The lipid content was significantly lower in morulae cultured in ITS-BSA compared with the two other media (320 ± 10 arbitrary fluorescence units vs. 383 ± 12 in FCS and 406 ± 10 in ITS-PVP; n = 271; ANOVA2: P < 0.01). After cryopreservation, a higher total hatching rate was found 24 h post-thawing in blastocysts cultured in ITS-BSA and for both serum-free conditions at 48 h (Table 1). In particular, embryos ≤180 µm cultured in FCS were less resistant to cryopreservation than embryos of the same size produced without serum. Expanded blastocysts cultured in ITS-BSA were sexed by PCR (Grisart et al. 1995 Theriogenology 43, 1097) and a higher proportion of male embryos was found (62.7%; n = 51). In conclusion, a complete serum-free system was set up from oocyte maturation to embryo cryopreservation that gave high quality embryos resistant to cryo-preservation. Embryos produced in ITS-BSA presented a lower lipid content, but a shift of the expanded blastocyst sex ratio toward males was observed. Table 1. Hatching rates post-thawing as a function of the blastocyst size and the culture medium


2006 ◽  
Vol 18 (2) ◽  
pp. 149 ◽  
Author(s):  
L. Beebe ◽  
S. McIlfatrick ◽  
R. Ashman ◽  
M. Nottle

Porcine embryo cryopreservation is an important technology for the storage and transport of valuable genetic material. With many of the current vitrification and storage systems, such as the open pulled straws and microdrops, there is direct contact between the medium containing the embryos and the liquid nitrogen. This represents a possible contamination risk. One system with which there is no direct contact between the embryos and liquid nitrogen during the vitrification process is the Cryologic Vitrification System (CVM; Lindemans et al. Reprod. Fertil. Dev. 16, 174) which uses solid surface vitrification. Microdrops of vitrification medium containing the embryos are placed in contact with a metal block that has been precooled by partial submersion in liquid nitrogen, resulting in very rapid cooling rates. Blastocysts were collected surgically on day 5 of pregnancy from mature sows, and the embryos were randomly divided into two groups; each group was then vitrified and warmed with either of two previously published protocols except that the CVM replaced the open pulled straws plunged into liquid nitrogen in both protocols. The first method (OPS/CVM) was based on the open pulled straw method (Cuello et al. Theriogenology 61, 843-850), and used DMSO and ethylene glycol as cryoprotectants and TCM-199 as the basic medium. The second method (EG/CVM) used HEPES-buffered NCSU23 as the basic medium; the blastocysts were centrifuged prior to vitrification in ethylene glycol and polyvinylpyrrolidone (PVP) and the zona pellucida was removed immediately after warming (Cameron et al. Theriogenology 61, 1533-1543). Embryos were then cultured in NCSU23 +10% fetal bovine serum for 48 h at 38.5�C in an humidified atmosphere of 5% CO2, 5% O2, and 90% N2. Embryos that had reformed the blastocoel and continued to expand were considered to have survived. These were stained with Hoechst 33342 and the nuclei counted using fluorescence microscopy. There was no difference between the OPS/CVM or EG/CVM methods in either the survival rates (27/29; 93%, and 24/27; 89%, respectively) or the number of cells (mean � SEM; 109 � 6 and 112 � 6, respectively). The survival rates are comparable to previously published rates using these two methods and open pulled straws. These data suggest that the CVM can successfully replace the open pulled straws in these two protocols. However, transfer of vitrified and warmed embryos into recipients would be needed to confirm the viability of the surviving embryos.


2006 ◽  
Vol 18 (2) ◽  
pp. 243
Author(s):  
L. S. A. Camargo ◽  
J. H. M. Viana ◽  
W. F. Sa ◽  
A. M. Ferreira ◽  
A. A. Ramos ◽  
...  

The effects of heat stress on Bos taurus reproductive performance in tropical and subtropical regions are well known, and have been associated with lower oocyte developmental capacity. The aim of this study was to evaluate the developmental competence of oocytes from Bos taurus (Holstein) and Bos indicus (Gyr) dairy cows raised in a Brazilian tropical region, located at 21°35′S latitude, 43°51′W longitude, and 435 meters altitude. Cumulus–oocyte complexes (COCs) were recovered by oocyte pickup (OPU) from mature non-lactating Holstein (n = 9) and Gyr (n = 13) donor cows between the end of spring and the beginning of autumn, with at least two OPU sessions/cow. COCs were in vitro-maturated in TCM-199 (GIBCO, Grand Island, NY, USA) with 10% inactivated estrus cow serum for 24 h under 5% CO2 at 38.5°C in air. Bos taurus and Bos indicus semen with similar cleavage rates, previously evaluated by in vitro fertilization with oocytes obtained from slaughterhouse ovaries, were used to reduce bull effect. Holstein and Gyr spermatozoa were obtained through swim-up method and co-incubated with Holstein (n = 390) and Gyr (n = 505) oocytes, respectively, in Fert-TALP medium (Parrish et al. 1988 Biol. Reprod. 38, 1171–1180) supplemented with 10 μg/mL heparin (Sigma-Aldrich, Sao Paulo, Brazil) and 6 mg/mL fatty acid-free bovine albumin (Sigma) for 18 h in 5% CO2 at 38.5°C in air. Presumptive zygotes were co-cultured with their own cumulus cells in CR2aa medium (Wilkinson et al. 1996 Theriogenology 45, 41–49) supplemented with 10% fetal calf serum in humid atmosphere of 5% CO2 at 38.5°C in air. On Day 7 to 8 of co-culture, Gyr and Holstein blastocysts were assessed and those classified as grade 1 (IETS Manual) were transferred to synchronized Bos indicus × Bos taurus crossbred recipients managed under the same nutritional and environmental conditions. Pregnancy diagnosis was performed between 35 and 50 days after estrus. Cleavage, blastocyst, and pregnancy rates were analyzed by chi-square test. Cleavage and blastocyst rates were greater (P < 0.05) in Gyr than in Holstein (66.7% vs. 53.1% for cleavage and 19.6% vs. 10.8% for blastocyst, respectively), but the pregnancy rate was similar (P > 0.05; 44.5% vs. 60% for Gyr and Holstein, respectively). These results show that Gyr oocytes obtained in a tropical region have greater developmental capacity than Holstein oocytes, suggesting an interaction between genotype and environment that influences the success of an in vitro embryo production program; nevertheless, the blastocyst viability after transferring to recipients is similar for both breeds.


2004 ◽  
Vol 16 (2) ◽  
pp. 164 ◽  
Author(s):  
L.S.A. Camargo ◽  
R.S. Oliveira ◽  
J.H.M. Viana ◽  
W.F. Sá ◽  
A.M. Ferreira ◽  
...  

Dairy herds in tropical countries are often maintained as crossbred B. indicus×B. taurus hybrids to take advantage of heterosis, such as resistance to heat stress. Creating crossbred B. indicus×B. taurus embryos by in vitro methods may offer a means of rapidly improving tropical dairy herds, especially if the embryos can be cryopreserved. The aim of this study was to compare the viability of in vitro-produced crossbred B. indicus×B. taurus embryos (1/2, 3/4) using two vitrification solutions and equilibration/dilution temperatures. Cumulus-oocyte complexes were aspirated from purebred B. indicus and crossbred (B. indicus×B. taurus hybrid) ovaries, matured in vitro, and fertilized with spermatozoa collected from a Holstein bull. Presumptive zygotes were co-cultured in CR2aa medium with cumulus cells, in a humid atmosphere of 5% CO2-air at 38.8°C. On day 7 of co-culture, embryos were assessed and classified as good or excellent, and those at the appropriate developmental stage were vitrified using one of two vitrification solutions, a mixture of either glycerol/ethylene glycol (GE) or dimethylsulphoxide/ethylene glycol (DE). Embryos (n=34) assigned to GE vitrification were equilibrated in a medium of PBS+20% FCS (HM1) containing 10% v/v G for 5min, followed by 10% v/v G+20% v/v E for 5min., and then transferred to a vitrification solution of 25% v/v G+25% v/v E in HM1 for 30s. The embryos were immediately aspirated into an Open Pulled Straw (OPS) and plunged into liquid nitrogen. Embryos vitrified in GE were warmed by immersing the OPS in HM1 containing 1M sucrose for 1min (37°C), then stepwise diluted in fresh HM1 containing 1M, 0.5M, and 0.25M sucrose for 5min; and finally washed in HM1. Stepwise equilibration and dilution of GE embryos was at 20°C. Embryos (n=43) assigned to DE vitrification were equilibrated in a medium of PBS+5% FCS (HM2) containing 10% v/v D+10% v/v E for 1min, and then transferred to a vitrification solution of 20% v/v D+20% v/v E in HM2 for 30s. The embryos were immediately aspirated into an Open Pulled Straw (OPS) and plunged into liquid nitrogen. Embryos vitrified in DE were warmed by immersing the OPS in HM2 containing 0.25M sucrose for 1min (39°C), then stepwise diluted in fresh HM2 containing 0.25M and 0.15M sucrose for 5min, and finally washed in HM2. Stepwise equilibration and dilution of DE embryos was at 39°C. Diluted embryos from both groups and untreated control embryos (n=49) were cultured in TCM-199 with monolayer granulosa cells for 72h in conditions described above. Blastocyst re-expansion and hatching was assessed and analyzed by chi-square test. Overall, 67% of the thawed embryos were expanded blastocysts (remainder were blastocysts) and 56% were excellent quality (remainder were good). No significant difference (P&gt;0.05) was found between the rates of blastocyst re-expansion and hatching for the GE and DE vitrification procedures (respectively, 59 and 79%, and 41 and 58%). However the hatching rate of control embryos (77%) was significantly higher than that of vitrified embryos (P&lt;0.05). These results indicate that both vitrification procedures are promising for the cryopreservation of crossbred B. indicus×B. taurus in vitro-produced embryos. Supported by CNPq.


2011 ◽  
Vol 23 (1) ◽  
pp. 173
Author(s):  
M. J. Sudano ◽  
D. M. Paschoal ◽  
T. S. Rascado ◽  
L. C. O. Magalhães ◽  
L. F. Crocomo ◽  
...  

Phenazine ethosulfate (PES) is a metabolic regulator that inhibits fatty acid synthesis and favours the pentose-phosphate pathway. Supplementation of fetal calf serum (FCS) during culture has been correlated with the reduction of quality of in vitro produced bovine embryos (IVPE). The aim of the present study was to evaluate embryo development and apoptosis in blastocysts after the supplementation of PES and FCS in culture medium of IVPE. Oocytes (N = 4320) were matured and fertilized in vitro (Day 0). The zygotes (Bos indicus) were cultured in SOFaa medium with 4 concentrations of FCS (0, 2.5, 5, and 10%) and with the use or not of 0.3 μM PES from Day 4 (after 96 h of embryo culture). Embryo development was evaluated after 7 days of culture. Apoptosis in blastocysts (N = 60–80) was accessed through TUNEL reaction. Embryos (Bos indicus) recovered from superstimulated cows were used as in vivo control (n = 15). Data were analysed by ANOVA followed by LSD using PROC GLIMMIX (SAS; SAS Institute Inc., Cary, NC, USA) means ± SEM. Increasing FCS concentration in the culture media did not change cleavage (86.7 ± 1.7, 82.3 ± 1.6, 86.3 ± 1.4, 87.0 ± 1.5, P > 0.05) and augmented blastocyst production (30.5 ± 2.5a, 41.8 ± 2.4b, 40.5 ± 2.6b, 47.2 ± 2.8b, P < 0.05), respectively, for 0, 2.5, 5, and 10%. Additionally, increasing FCS concentration increased apoptosis in blastocysts (13.8 ± 1.2b, 19.1 ± 1.8b, 20.7 ± 1.9bc, 28.4 ± 2.3c, P < 0.05, respectively, for 0, 2.5, 5, and 10%). The addition of PES from Day 4 in the culture medium did not affect (P > 0.05) cleavage (87.0 ± 1.3 and 84.4 ± 1.3), blastocyst production (42.0 ± 2.8 and 43.0 ± 2.0), and apoptosis in blastocysts (20.7 ± 2.0b and 18.9 ± 2.1b), respectively, for control and PES Day 4 groups. Independent of FCS withdrawal or PES addition to culture medium, the in vivo control group presented the lowest apoptosis rate (6.3 ± 1.1a). Therefore, increasing FCS concentration augmented embryo development and reduced blastocyst quality. However, the addition of 2.5% of FCS in the culture medium increased the embryo development without the reduction of blastocyst quality. Moreover, the PES supplementation from Day 4 did not affect embryo development and blastocyst quality. São Paulo Research Foundation – FAPESP.


Author(s):  
Anita Soares Barbosa GUIMARÃES ◽  
Laiara Fernandes ROCHA ◽  
Ronival Dias Lima de JESUS ◽  
Gisvani Lopes VASCONCELOS ◽  
Gabriela ANGHINONI ◽  
...  

ABSTRACT In this study, the in vitro production of bovine embryos from zebu and taurine donors was compared. Cumulus-oocyte complexes (COCs) were obtained from 167 Bos taurus and 161 Bos indicus donors by ovum pick-up. COCs were classified based on their morphological quality, matured in incubators for 22 to 24 h in maturation medium, and then fertilized for 18 to 22 h. The zygotes were transferred to the culture medium for seven days. The embryos were classified as morula (OM), initial blastocyst (BI), blastocyst (BL), and expanded blastocyst (BX), before being transferred to synchronized recipient cows. Pregnancy was diagnosed 30-45 days post-transfer. The Bos indicus donors had a higher oocyte yield (n = 2556) than Bos taurus donors (n = 1903) (P = 0.008). The COCs from zebu donors had a better morphological quality than those from taurine donors (n = 689 vs. 444 for grade 1 COC, P < 0.0001; n = 681 vs. 509 for grade 2 COC, P = 0.010, for zebu and taurine donors, respectively). There were differences in embryo production percentages obtained from OM (0.44% from zebu and 6.42% from taurine, P = 0.017), BL (14.18% from zebu and 3.74% from taurine, P < 0.0001), and BX (81.43% from zebu and 75.13% from taurine, P < 0.0001). No significant difference was observed for embryo production from BI and pregnancy rate (P > 0.05). The Bos indicus cows showed greater oocyte recovery, number of viable oocytes, and production of viable embryos than the Bos taurus cows.


2009 ◽  
Vol 21 (1) ◽  
pp. 136
Author(s):  
A. C. Nicacio ◽  
R. Simões ◽  
M. A. Peres ◽  
J. S. A. Gonçalves ◽  
F. F. Paula-Lopes ◽  
...  

The inefficiency of embryo cryopreservation protocols limits the broad use of in vitro production (IVP) of bovine embryos. The aim of this work was to identify the damage caused by cryopreservation and embryo culture of IVP bovine embryos after thawing by in vitro development before and after cryopreservation. Cumulus–oocyte complexes were in vitro-matured, fertilized, and cocultured on granulosa cells in SOF with amino acids (SOFaa) supplemented with FCS. Expanded blastocysts (n = 600) harvested on Days 7 to 9 were submitted to controlled freezing [controlled group: 10% ethylene glycol (EG) for 10 min and 1.2°C min–1 cryopreservation], quick-freezing [quick group: 10% EG for 10 min, 20% EG + 20% glycerol (Gly) for 30 s], or vitrification [vitrification group: 10% EG for 10 min, 25% EG + 25% Gly for 30 s] protocols. The embryos of the control group were not exposed to cryoprotectant or cryopreservation method, and the hatching rate was evaluated on Day 12 post-insemination. The straws (quick and vitrification groups) were first placed on nitrogen vapor (0.8 cm over the liquid nitrogen) for 2 min and then immersed in liquid nitrogen. Embryos were thawed in air for 10 s followed by a 25°C water bath for 20 s. Embryos were rehydrated in PBS + 0.2% BSA + 0.3 m sucrose and PBS + 0.2% BSA for 3 min each. To evaluate development of frozen–thawed embryos, they were cocultured on granulosa cells in TCM-199 or SOFaa both supplemented with FCS for 4 days. Hatching rate of the control group was 46.1%. Data were analyzed by PROC MIXED model of SAS System for Windows®. For TCM-199, the controlled group hatching rate was 44.65 ± 5.94%, quick group did not hatch, and vitrification group showed hatching rates of 9.4 ± 6.8%. For SOFaa, the controlled group hatching rate was 11.6 ± 3.4%, embryos submitted to the quick group did not hatch, and the vitrification group showed hatching rates of 8.7 ± 4.5%. Values were significant at P < 0.05. The controlled group showed a difference compared with the other groups of cryopreservation in both media (TCM-199 and SOFaa). However, TCM 199 showed high rates of re-expansion and hatching. In conclusion, the culture medium influences embryo development after cryopreservation, and TCM-199 is more appropriate than SOFaa. Financial support by FAPESP (04/05335-1).


2011 ◽  
Vol 75 (3) ◽  
pp. 429-433 ◽  
Author(s):  
F.G. Leivas ◽  
D.S. Brum ◽  
S.S. Fialho ◽  
W.P. Saliba ◽  
M.T.T. Alvim ◽  
...  

Zygote ◽  
2021 ◽  
pp. 1-7
Author(s):  
Larissa Zamparone Bergamo ◽  
Denis Vinicius Bonato ◽  
Camila Bizarro-Silva ◽  
Francieli Gesleine Capote Bonato ◽  
Tamires Korchovei Sanches ◽  
...  

Summary The aim of this study was to evaluate the follicular development, morphological integrity, and oxidative stress of preantral ovarian follicles from Bos taurus indicus females grown in vitro with ascorbic acid. Ovaries (n = 20) from Bos taurus indicus females were collected, fragmented, and were cultured in vitro for 6 or 12 days in minimum essential medium (MEM), or MEM supplemented with 50 or 100 ng/ml ascorbic acid, with an extracellular matrix of agarose gel, in an incubator at 38.5°C; every 2 days, 100% of the culture medium was replaced. The data were analyzed using the chi-squared test and/or Fisher’s exact test. In the event of a significant effect, the proportions were compared using a 2 × 2 proportion test. The oxidative stress analysis data were submitted to analysis of variance followed by the Bonferroni test. Values were considered significant when P ≤ 0.05. The addition of 100 ng/ml of ascorbic acid to the in vitro culture medium of preantral ovarian follicles from bovine females promoted follicular development, was efficient in maintaining morphological integrity, as well as the stability of reactive oxygen species, after 6 days of in vitro culture.


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