249 AN EFFICIENT AND REPEATABLE IN VITRO FERTILIZATION TECHNIQUE IN THE EQUINE FOR PRESERVATION OF ENDANGERED SPECIES

2015 ◽  
Vol 27 (1) ◽  
pp. 214
Author(s):  
C. Douet ◽  
O. Parodi ◽  
F. Reigner ◽  
P. Barrière ◽  
G. Goudet

Most wild equids are currently endangered or threatened, as mentioned in the International Union for the Conservation of Nature Red List, and several domestic horse breeds are at risk of extinction. Genome resource banking requires cryoconservation of semen, oocytes, and/or embryos. Embryo production in equids is limited in vivo because routine induction of multiple ovulation is still ineffective. Embryo production in vitro allows the production of several embryos per cycle that could easily be frozen because of their small size. Intracytoplasmic sperm injection has been widely adopted to generate horse embryos in vitro; however, intracytoplasmic sperm injection is time-consuming and requires expensive equipment and expertise in micromanipulation. Several attempts to establish an efficient IVF technique in the equine were performed, but reported IVF rates remain quite low and no repeatable equine IVF technique was available. Our objective was to develop an efficient and repeatable IVF technique in the equine. Immature cumulus-oocyte complexes (COC) were collected either from slaughtered mares in a local slaughterhouse or from our experimental mares by ovum pick up (OPU). The COC were cultured for 26 h in an in vitro maturation (IVM) medium or in preovulatory follicular fluid (FF) collected by OPU, pre-incubated for 30 min in oviducal fluid collected from slaughtered females, co-incubated for 18 h with fresh spermatozoa treated with procain, and cultured in SOF for 30 h. They were fixed and analysed either after 18 h IVF (experiment 1) or after 30 h in vitro development (experiment 2). In experiment 1, COC were collected from slaughtered mares and analysed after 18 h IVF. Zygotes with 2 pronuclei were observed. The IVF rate was similar for oocytes matured in IVM medium (22/33, 67%) or FF (24/42, 57%; chi-square test, P > 0.05). In experiment 2, COC were collected from slaughtered mares and from experimental mares and analysed after 30 h of in vitro development. We observed zygotes with 2 highly decondensed pronuclei, pronuclei decondensation being the first step of embryo development. For oocytes collected from slaughtered mares, the percentage of zygotes was similar for oocytes matured in IVM medium (8/11, 73%) or FF (10/15, 67%). For oocytes collected by ovum pickup, the percentage was similar for IVM medium (3/5, 60%) or FF (6/8, 75%). We also observed some embryonic structures with several nuclei, but the quality of these embryos was poor. In conclusion, we have established an efficient IVM-IVF technique that allows the first step of embryo development. Because we obtained similar results for 4 years, we consider that this efficient technique is repeatable. Further experiments are in progress to improve the quality of the embryos.

2006 ◽  
Vol 18 (2) ◽  
pp. 187
Author(s):  
J. De la Fuente ◽  
A. Gutiérrez-Adán ◽  
P. Beltrán Breña ◽  
S. S. Pérez-Garnelo ◽  
A. T. Palasz

It is assumed that, contrary to phosphate buffers, zwitterionic buffers are neutral. However, zwitterionic buffers containing hydroxymethyl or hydroxyethyl residues may interact with OH-groups in the media and produce formaldehyde (Shiraishi et al. 1993 Free Radic. Res. Commun. 19, 315-321). Also, it was shown that three zwitterionic buffers tested in this study interact with DNA (Stellwagen et al. 2000 Anal. Biochem. 287, 167-175). Our objective was to evaluate the effect of the following buffers: TES (T), MOPS (M), HEPES (H) (pKa values at 20�C: 7.2-7.5), and PBS on in vitro development and morphology of bovine embryos. Zwitterionic buffers and PBS were prepared at a concentration of 10 mM in TALP medium and the final pH was adjusted to 7.2. Bovine follicular fluid was aspirated from abattoir-derived ovaries and evenly divided into four tubes. Collected oocytes (five replicates) from each tube were processed separately through the entire IVM, IVF, and IVC procedures using washing medium buffered with: PBS (n = 490), Group 1; H (n = 438), Group 2; M (n = 440), Group 3; and T (n = 394), Group 4. All buffers contained 4 mg/mL BSA. Oocytes were matured in TCM-199 + 10% FCS and 10 ng/mL of epidermal growth factor and fertilized in Fert-TALP containing 25 mM bicarbonate, 22 mM sodium lactate, 1 mM sodium pyruvate, 6 mg/mL BSA-FAF, and 10 �g/mL heparin with 1 � 106 spermatozoa/mL. After 24 h, oocytes-sperm co-incubation presumptive zygotes were cultured in SOFaa medium with 8 mg/mL BSA at 39�C under paraffin oil and 5% CO2 in humidified air. Cumulus-oocyte complexes and zygotes were held in designated buffers ?16 min before oocyte maturation, ~7 min after IVM and before IVF, and ~18 min after IVF and before culture. The total time of oocyte/embryo exposure to each buffer was ?41 min. Embryo development was recorded on Days 4, 7, 8, and 9. A total of ten, Day 8 blastocysts were taken randomly from each treatment and fixed in 4% paraformaldehyde for total and apoptotic cells counts, and five blastocysts from each replicate and treatment were frozen for later mRNA analysis. Apoptosis were determined by TUNEL, using commercial In situ Cell Death Detection Kit (Roche Diagnostic, SL, Barcelono, Spain). Embryo development among groups was compared by chi-square analysis. The cleavage rates were not different among the groups: PBS, 70.8%; H, 76.5%; M, 77.5% and T, 73.6%. The number of embryos that developed to d8 cells at Day 4 was higher in M, 36.2%, and PBS, 37.6%, than in H, 30.6%, and T, 29.7%, but was not significantly different. However, more (P < 0.05) blastocysts developed at Days 7, 8, and 9 in H and M than in PBS and T groups (21.9% and 22.9% vs. 16.9% and 14.9%, respectively). No difference was found between groups in total cell number (98.8 � 7, PBS; 111.8 � 11.9, M; 106.8 � 12.9, H; and 104.3 � 9.7, T) and the number of apoptotic cells (9.2 � 1.0, P; 9.2 � 0.8, M; 12.9 � 1.8, H; and 9.7 � 0.9, T). Based on the results of this study, we conclude that within our protocol choice of buffer may affect embryo developmental rates but not morphology.


2013 ◽  
Vol 25 (1) ◽  
pp. 174
Author(s):  
R. Olivera ◽  
C. Alvarez ◽  
I. Stumpo ◽  
G. Vichera

The time allowed for nuclear reprogramming is considered an essential factor for the efficiency of cloning and has not been evaluated in equine aggregated cloned embryos. The aim of our work was to assess the effect of different timing of activation stimulus after fusion of adult equine fibroblast cells to enucleated equine oocytes on embryo development and embryo quality. We processed a total of 1874 equine ovaries, recovering 3948 oocytes, of which 1914 (48.5%) had extruded the first polar body after 24 h of maturation. Oocyte collection, maturation, and the NT procedure were performed as described by Lagutina et al. (2007 Theriogenology 67, 90–98). Reconstructed oocytes (RO) were activated at 3 different times after cell fusion: (1) 1 h, (2) 1.5 h, and (3) 2 h. Activation was performed using 8.7 µM ionomycin for 4 min, followed by a 4-h culture in a combination of 1 mM DMAP and 5 mg mL–1 of cycloheximide. The RO were cultured in the well of the well system, aggregating 3 RO per well. The RO were cultured in DMEM-F12 with 5% fetal bovine serum (FBS) and antibiotics. Cleavage (48 h after activation), blastocyst, and expanded blastocyst rates (8–9 days) were assessed. In vitro development was compared using the chi-square test (P < 0.05). A total of 1608 RO were cultured. Cleavage was significantly lower in group 3 with respect to the other 2 groups [(1): 396/450, 88%; (2): 540/639, 84.5%; (3): 365/519, 70.3%]. There were no significant differences in blastocyst rates within the 3 groups considering the number of total RO [(1): 19/450, 4.2%; (2): 23/639, 3.6%; (3): 15/519, 2.9%] or aggregated RO per well [(1): 12.7%; (2): 10.8%; (3): 8.7%]. However, the rate of blastocyst expansion was higher (P < 0.05) in group 2 than in group 3 [(1): 17/19, 89.5%; (2): 23/23, 100%; (3): 11/15, 73.3%]. In conclusion, the timing of nuclear reprogramming did not affect blastocyst rates but affected cleavage rates and blastocyst quality. This indicates that 1 h before activation stimulus is enough for embryo development of equine aggregated cloned embryos.


2011 ◽  
Vol 23 (1) ◽  
pp. 124
Author(s):  
C. Feltrin ◽  
M. Machado ◽  
L. M. V. Queiroz ◽  
M. A. S. Peixer ◽  
P. F. Malard ◽  
...  

In vitro embryo production by handmade cloning (HMC) usually requires individual embryo culture, because zona-free embryos cannot be grouped in standard in vitro culture (IVC) protocols. The aim of this study was to evaluate the developmental potential of bovine embryos produced by HMC (Ribeiro et al. 2009 Cloning Stem Cells 11, 377–386) after in vitro culture (IVC) in 3 microwell (WOW) systems. After in vitro maturation, oocytes were denuded and incubated in demecolcine (Ibáñez et al. 2003 Biol. Reprod. 68, 1249–1258), followed by zona pellucida removal, oocyte bisection, embryo reconstruction, electrofusion, and chemical activation. Cloned embryos were allocated to 1 of 3 IVC groups: cWOW: conventional microwells (250 μm, round; Vajta et al. 2000 Mol. Reprod. Dev. 55, 256–264); mWOW: modified microwells (130 μm, conical; Feltrin et al. 2006 Reprod. Fert. Dev. 18, 126); and WOW-PDMS: microwells in polydimethylsiloxane chips (170 μm, cylindrical with microchannels); IVF embryos were used as controls (Bertolini et al. 2004 Reproduction 128, 341–354). Cleavage (Day 2), blastocyst (Day 7), and pregnancy (Day 30) rates were analysed by the chi-square test, for P < 0.05. Results are shown in Table 1. Cleavage rates were similar between groups, but development to the blastocyst stage was higher in IVF controls than cloned embryo groups. Among cloned embryo groups, blastocyst rate was higher in the mWOW group than the conventional and the PMDS-based microchannels. Nevertheless, in vivo development to Day 30 of pregnancy was not different between cloned groups. Our results for in vitro embryo development indicated that the mWOW provided more suitable conditions for embryo development to the blastocyst stage when compared with cWOW or even WOW-PDMS. Among some possible reasons include the physical advantage of a smaller microwell that may better mimic the constraining effect of the zona pellucida on the developing embryo. That may also provide greater blastomere stability, favouring the aggregation state during the first rounds of cleavages, also aiding compaction and subsequent cavitation. The narrower microwell system appeared to have promoted better in vitro development than the conventional and the DMPS-based microwell systems, with no impact on subsequent in vivo development. However, the IVC in the WOW-PDMS system supported reasonable rates of development, in accordance with the current literature. Table 1.In vitro development of bovine IVF and cloned embryos produced after the in vitro culture in distinct IVC systems


2012 ◽  
Vol 24 (1) ◽  
pp. 214
Author(s):  
J. Jarazo ◽  
A. Gambini ◽  
A. De Stefano ◽  
L. Muredas ◽  
J. G. Oriol ◽  
...  

Intracytoplasmic sperm injection (ICSI) is an alternative method for producing in vitro-fertilized embryos in horses. Some authors have suggested that using the piezo drill to inject the spermatozoon is required to obtain acceptable blastocyst rates after ICSI. In order to avoid the use of this equipment, the aim of our study was to evaluate 4 different chemical activation protocols and their effect on embryo development. Cumulus–oocyte complexes were recovered from ovaries of slaughtered mares. The maturation medium was DMEM/F12 supplemented with 10% fetal bovine serum (FBS), 1 μL mL–1 of insulin-transferrin-selenium, 1 mM sodium pyruvate, 100 mM cysteamine and 0.1 mg mL–1 of FSH at 39°C in a humidified atmosphere of 6.5% CO2 in air for 24 h. The ICSI was carried out in 20-μL droplets of TALP-HEPES with a 9-μm pipette, using frozen-thawed spermatozoa from 1 stallion. Spermatozoa were held separate in 100-μL droplets of Modified Whittens. Motile spermatozoa were aspirated and transferred to a 5-μL drop of 7% (v/v) polyvinylpyrrolidone, where 1 sperm was immobilized by swiping the injection pipette across its tail; then, the sperm was injected into the oocyte. All injected oocytes were subjected to 8.7 μM ionomycin for 4 min, followed by 1 of 3 further activation treatments: (1) 4-h culture in 1 mM 6-DMAP and 10 mg mL–1 of cycloheximide, starting 3 h after ionomycin; (2) 5-h culture in 10 mg mL–1 of cycloheximide, starting 10 min after ionomycin; (3) An extra incubation with 5 mM ionomycin for 4 min, starting 3 h after ionomycin. Some injected oocytes were left without a further activation protocol (group 4). After activation, injected oocytes were cultured in 100-μL droplets of DMEM/F12 with 5% of FBS at 39°C in a humidified atmosphere of 5% O2, 5% CO2 and 90% N2. Cleavage (48 h after activation) and blastocyst formation (7–8 days) of all experimental groups were assessed. Culture medium was renewed on Day 3 with fresh DMEM/F12 with 5% of FBS. At Day 9, the zona pellucida of some blastocysts was removed and the blastocysts were maintained in culture until Day 15. Blastocyst growth was determined every 24 h. Statistical differences (using chi-square analysis) were observed in cleavage with treatments 1 and 3 when compared to the other groups (1: 30/52, 58%; 2: 8/40, 20%; 3: 9/25, 36%; and 4: 10/38, 26%). There was no difference on blastocyst rates based on injected oocytes (1: 5/52, 9.6%; 2: 2/40, 5%; 3: 1/25, 4%; and 4: 2/38, 5.3%). On Day 7, blastocyst quality did not differ among treatments and on Day 15, blastocysts from groups 3 and 4 reached 1130 μm and 4300 μm, respectively. Despite the difference observed in cleavage, this work suggests that equine blastocysts could be obtained with all of the activation protocols, without the use of the piezo drill. Further studies are required to assess the effect of chemical activation on in vivo development of produced blastocysts to confirm that they are not parthenogenetic. We are grateful to Mr. Willem Melchior, La Vanguardia Polo Club for some financial support and encouragement to undertake this project.


2011 ◽  
Vol 23 (1) ◽  
pp. 166
Author(s):  
A. Gambini ◽  
J. Jarazo ◽  
R. Olivera ◽  
F. Karlanian ◽  
D. F. Salamone

Development of cloned equine embryo is still inefficient. The aim of our study was to assess the aggregation of zona-free genetically identical cloned embryos as a strategy to improve in vitro and in vivo development. Oocyte collection, maturation, cloning, and activation procedures were performed as described by (Lagutina et al. 2007 Theriogenology 67, 90–98). After activation, reconstructed embryos (RE) were cultured in DMEM/F12 with 5% of FBS in the well of well system in 3 different groups: I, only one RE per well; II, two RE per well; and III, three RE per well. Cleavage and blastocyst formation (7 to 8 days) of all experimental groups was assessed. At day 8, some embryos of each group were either fixed to determine Oct-4 expression by immunocytochemistry or transferred transcervically to a synchronized mare. Pregnancies were assessed by ultrasound from 7 days after embryo transfer until day 45 to 50 of pregnancy every 7 to 10 days, and sizes of vesicles and embryos were measured. In advanced pregnant mares, combined thickness of the uterus and the placenta (CTUP) and serum progesterone levels were also determined. The remaining embryos obtained from each group were maintained in culture from day 7 until day 15. Blastocysts growth was determined every 24 h. In vitro development, on a per-well and RE basis, was compared using the chi-square test. Statistical differences were observed in cleavage among groups I and II (P = 0.0088) and groups I and III (P = 0.0004): (I: 91/111, 82%; II: 74/78, 95%; III: 62/62, 100%). Blastocyst rates differed between groups I and III (I: 10/111, 9%; III: 23/62, 37%); no difference was observed with group II (11/78, 14%). There was no difference on blastocyst rates based on the number of aggregated RE (I: 10/111, 9%; II: 11/156, 7%; III: 23/184, 12.5%). The highest pregnancy rate was obtained in group III (I: 1/3, 33%; II: 2/5, 40%; III: 3/4, 75%). Sizes of vesicles and embryos did not differ statistically in such groups. The CTUP and serum progesterone levels were considered normal (<1.2 cm; >8 ng mL–1, respectively) in ongoing pregnancies. We did not observe any differences in Oct-4 expression patterns among groups. Even though statistical differences were found, surprisingly all embryos grew in vitro until day 15 with good rates and the biggest embryo reached 4.25 mm. Embryo aggregation improved in vitro development of equine cloned embryos until day 7, and pregnancies rates were higher. The in vivo sizes of vesicles and embryos were normal for all groups, and in vitro development beyond day 7 showed the high viability of embryos. To conclude, aggregation of cloned equine embryo does not imply extra oocytes because there is no statistical difference in the number of blastocysts obtained per oocytes used to achieve RE. It is also a good strategy to improve in vitro embryo development without alterations on in vivo progress. This is the first report of pregnancies from aggregated equine cloned embryos, and the first healthy cloned foal from South America, confirmed by STR analysis, was born recently derived from group II. Stumpo, Ignacio, Paola Barboza, and Don Antonio staff.


Reproduction ◽  
2002 ◽  
pp. 553-565 ◽  
Author(s):  
P Holm ◽  
PJ Booth ◽  
H Callesen

The kinetics of the in vitro development of early embryos from bovine zygotes derived in vitro and in vitro were compared, investigating the effect of serum during in vitro maturation and fertilization (IVM-IVF) and in culture. Zygotes were collected from superovulated heifers or produced in vitro from immature oocytes with or without serum supplementation, and cultured subsequently in defined culture medium (SOFaaci) with or without serum supplementation. Time-lapse images were recorded every 0.5 h throughout the culture period. More in vivo- than in vitro-derived zygotes developed to the compact morula or blastocyst stages (87% versus 47-54%, respectively; P < 0.05). Embryo development was blocked predominantly at the second or fourth cell cycles (28 and 29%). However, blastomeres degenerated at all cleavage stages. Serum supplementation during IVM-IVF resulted in abnormally sized blastomeres at first cleavage (defined serum: 20-22% versus in vivo-derived: 8%, P < 0.05). The duration of the second, third and fifth cell cycles of in vivo-derived zygotes were 1-5 h shorter compared with those of in vitro-derived zygotes cultured under similar conditions (P < 0.05). However, the kinetics of embryo development was affected by serum during IVM-IVF and culture. The first and fourth cell cycles were prolonged by 4-5 h in the absence of serum during IVM-IVF, whereas the presence of serum during culture decreased the duration of the fourth cell cycle and triggered premature blastulation. The results of this study illustrate the differences and similarities between the morphology and developmental kinetics of in vivo- and in vitro-derived zygotes, and show how serum supplementation during IVM-IVF and culture can alter these parameters.


2005 ◽  
Vol 17 (2) ◽  
pp. 311
Author(s):  
M. Nakai ◽  
K. Kikuchi ◽  
A. Takizawa ◽  
M. Ozawa ◽  
J. Noguchi ◽  
...  

The present study investigated the development in vivo and in vitro of in vitro matured porcine oocytes injected with a freeze-dried (FD) boar sperm head. In mice, DNA damage was induced during the holding period after rehydration and before sperm injection (Wakayama, T. and Yanagimachi, R. 1998, Nat. Biotechnol., 16, 639–641). Here, we examined the relationship between duration of rehydration of FD sperm and in vitro development of FD sperm-injected porcine oocytes. We also assessed the in vivo developmental competence of the injected oocytes after embryo transfer. Ejaculated boar spermatozoa were suspended in Pig-FM (Suzuki, K. et al. 2002, Int. J. Androl. 25, 84–93) and sonicated for 1 min to separate sperm heads from the tails. An aliquot (100 μL) of the sperm suspension was put into a glass tube and then pre-cooled at −40°C for 6 h. Each tube was attached to a freeze-dry system (DuraDry μP, FTS Systems, Stone Ridge, NY, USA) for 12 h. The ampules were closed and stored at 4°C for more than 7 days before use. For rehydration, 100 μL of distilled water was added into the ampules. In Experiment I, we injected FD sperm heads which were kept for 0–60, 60–120, or 120–180 min after rehydration. At 1 h after the injection, the injected oocytes were stimulated with a DC pulse and cultured for 6 days. The rate of blastocyst formation and the number of cells in the blastocysts were examined. Embryos after in vitro fertilization (IVF) were evaluated as a control. As shown in Table 1, the rates of blastocyst formation were not different (by χ2 test) for duration of rehydration and the control. However, the cell numbers of FD groups were lower (P < 0.05; by Student's t-test) than that in the control. In Experiment II, oocytes injected with a single FD sperm head and stimulated were transferred to both oviducts of a total of ten recipient gilts. Two recipients were diagnosed as pregnant at Day 30 of gestation. At Day 39, one of the pregnant recipients had an abortion, and two fetuses were recovered. The other pregnancy was not maintained. The results suggest that oocytes fertilized with a single FD sperm head have competence to be implanted and to develop to the early fetal stage, and also that the duration for rehydration does not influence in vitro developmental ability in pigs. Table 1. Effects of the duration from rehydration of freeze-dried sperm heads to the injection of the heads into in vitro matured oocytes on in vitro development of the oocytes in pigs


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