74 EFFECT OF BETA-MERCAPTOETHANOL ON THE VITRIFICATION CRYOTOLERANCE OF BOVINE IN VITRO-PRODUCED EMBRYOS

2009 ◽  
Vol 21 (1) ◽  
pp. 137
Author(s):  
E. S. Ribeiro ◽  
M. C. Gonçalves ◽  
M. C. Pedrotti ◽  
L. T. Martins ◽  
R. P. C. Gerger ◽  
...  
Keyword(s):  
Cell Number ◽  
Blastocyst Stage ◽  
High Humidity ◽  
In Vitro Production ◽  
Chi Square ◽  
Embryo Survival ◽  
Chi Square Test ◽  
Vitro Production ◽  
Hatching Rates

The control of oxidative processes in in vitro production (IVP) systems by the use of additives may be an alternative approach to improve embryo cryotolerance. The aim of this study was to verify the effect of β-mercaptoethanol (βME) on the cryotolerance of bovine IVP embryos. In 7 replications, and following IVM-IVF, presumptive zygotes (n = 3735) were in vitro-cultured in SOF medium supplemented or not with 100 μm βME (IVC treatment), at 38.5°C and high humidity. The initial 24 h of IVC was performed in 5% CO2 in air, with the remaining 6 days of IVC carried out in 5% CO2, 5% O2, and 90% N2. On Day 7, resulting blastocysts and expanded blastocysts were vitrified in glass micropipettes in a solution with 20% ethylene glycol + 20% propylene glycol. After warming, embryos were randomly allocated to 1 of 2 sub-groups for an additional 72 h of IVC to the hatching blastocyst (HBL) stage, in fresh SOF medium supplemented or not with 100 μm βME (PVC treatment), at 38.5°C, high humidity and 5% CO2. Experimental groups were as follows: G1 (βME-free medium during IVC and PVC); G2 (βME only during PVC); G3 (βME only during IVC); and G4 (βME during IVC and PVC). Cleavage (Day 2) and blastocyst (Day 7) rates in the IVC treatment and hatching rates (Days 7 to 9) for the PVC treatment were analyzed by the chi-square test, for P < 0.05. Total cell number (TCN) estimated by fluorescence staining in HBL derived from vitrified and nonvitrified embryos was analyzed by ANOVA. The use of βME during IVC did not affect cleavage rates (βME-free, 1491/1858, 80.2% v. βME, 1522/1877, 81.1%), but negatively affected development to the blastocyst stage (βME-free, 813/1858, 43.8% v. βME, 525/1877, 28.0%). Following vitrification, however, βME supplementation during PVC improved hatching rates (G2, 58.1% and G4, 63.8%) compared with groups without the additive (G1, 36.6% and G3, 42.0%). In addition, the presence of βME either during IVC or PVC, or during both culture periods, increased TCN in HBL from vitrified embryos (Table 1). The use of βME during IVC, irrespective of the presence of βME during the PCV period, caused an increase in TCN in HBL in G3 + G4, with no effects on hatching rates (Table 1b), whereas the addition of βME during PVC, irrespective of the presence of βME during the IVC period, resulted in greater hatching rates and TCN in HBL in G2 + G4 than in G1 + G3 (Table 1). In conclusion, the addition of βME during the IVC period did not affect cleavage, but reduced blastocyst yield. Despite that, βME supplementation during the IVC period appeared to have increased the cryotolerance of the resulting blastocysts, expressed by greater TCN in HBL, whereas βME supplementation during the PVC period also improved embryo survival to the vitrification process, manifested by greater hatching rates and TCN in HBL. Table 1.Effect of βME on the cryotolerance of bovine IVP embryos This study was supported by a grant from CNPq/Brazil.

288 KINETICS OF FERTILIZATION, DEVELOPMENT, AND SEX RATIO OF IN VITRO-PRODUCED BOVINE EMBRYOS OBTAINED WITH FOUR DIFFERENT BULLS

2007 ◽  
Vol 19 (1) ◽  
pp. 259 ◽  
Author(s):  
M. Alomar ◽  
H. Tasiaux ◽  
S. Remacle ◽  
F. George ◽  
D. Paul ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Time Lapse ◽  
Blastocyst Stage ◽  
Bovine Embryos ◽  
In Vitro Production ◽  
Chi Square ◽  
Cell Stage ◽  
Chi Square Test ◽  
Kinetics Of

The between-bulls variation in in vitro fertility and the shift of sex ratio toward male embryos are two problems affecting the in vitro production (IVP) of bovine embryos. Our objective was to evaluate the possible correlation between the kinetics of fertilization, embryo development, and the sex ratio of the resulting embryos. In a first experiment, and using frozen-thawed semen of 4 different AI bulls, the kinetics of pronucleus (PN) formation was evaluated at 8, 12, and 18 h post-in vitro insemination (hpi) after fixation and staining with Hoechst 33342. Fertilized oocytes were classified in 3 PN stages: PN1: showing the first signs of sperm head decondensation; PN2: with two pronuclei of different sizes, the two being far from each other; and PN3: showing two symmetric pronuclei of equal size, close to each other. Differences between bulls were observed at each time point, but were greater at 12 hpi than at 8 or 18 hpi. At 8 hpi and 12 hpi, bull C showed a significantly faster PN formation by comparison with the 3 other bulls (chi-square test: P &lt; 0.05), whereas at 18 hpi, the proportion at each of the PN stages was similar to that of bulls A and D, with bull B showing delayed PN development. In a second experiment, a standard IVP procedure was conducted with the 4 bulls to determine cleavage and blastocyst rates. The timing of first cleavage was measured using time-lapse cinematography. Compared with those of bull B, the embryos generated with bull C led to significantly higher Day 7 blastocyst yields (31.3 � 9.5% vs. 21.9 � 6.7%; ANOVA: P &lt; 0.05). Moreover, the embryos from bull C reaching the blastocyst stage cleaved faster (first cleavage at 23.1 � 2.1 hpi vs. 25.4 � 2.7 hpi for bull B; ANOVA: P &lt; 0.05). In a third experiment, 65 to 76 Day 8 blastocysts were sexed per bull. Embryo sexing was performed by PCR using the co-amplification of a Y-specific bovine SRY sequence and an autosomal btRep-137 sequence. Only blastocysts obtained with bull C showed a shift in sex ratio toward male embryos (76.0% male embryos vs. 53.8% for bull B; chi-square test: P &lt; 0.05), whatever the size of the blastocyst. The shift in sex ratio was already present at the 2-cell stage (64.2% male embryos; n = 53; chi-square test: P &lt; 0.05). In conclusion, for 2 out of 4 bulls, a correlation was observed between the kinetics of PN formation, the timing of first cleavage, and the sex ratio of the resulting embryos.

290 THE FACTORS ON RATES OF ABNORMALITY, DISEASE AND MORTALITY OF CALVES DERIVED FROM IN VITRO EMBRYOS OF KOREAN NATIVE CATTLE

2006 ◽  
Vol 18 (2) ◽  
pp. 252
Author(s):  
Y.-S. Park ◽  
S.-S. Kim ◽  
M.-C. Park ◽  
H.-D. Park
Keyword(s):  
Calf Serum ◽  
Treatment Technique ◽  
In Vitro Production ◽  
Chi Square ◽  
Offspring Number ◽  
Chi Square Test ◽  
Native Cattle ◽  
Vitro Production ◽  
Delivery Type

In Korea, in vitro production and transfer of bovine embryos has advanced remarkably and applied commercially. However, in vitro-produced embryos result in lower pregnancy and higher abortion rates and in some cases increased rates of abnormality and mortality in calves. The present study was conducted to investigate the effects of various factors such as recipient parity, delivery season, offspring number, pregnancy period, delivery type, midwifery type, dystocia and vaccination, on the viability of calves derived from embryos produced in vitro. Korean Native Cow ovaries were obtained from local slaughterhouse and cumulus-oocyte complexes (COCs) were aspirated from 2 to 8 mm follicles. Selected COCs were matured in TCM-199 supplemented with 10% fetal calf serum (FBS), 1 �ML FSH, 10 �ML LH and 1 �ML Estradiol-17� for 20-22 h. In vitro-matured oocytes were fertilized using frozen-thawed percoll separated semen (Day 0) in fer-TALP medium for 20 h. The presumptive zygotes were cultured in CR1aa medium supplemented with 0.3% BSA (before Day 3) or 10%FBS (After Day 3). All types of cultures were made in an incubator at 38.5�, 5% CO2 in air. Statistical analysis was performed using the Chi-square test. Two blastocysts were transferred to the Holstein recipients (n = 1888). The parturition was occurred in total 755 recipients. There was no difference in the abnormality of calves among treatments. The incidence of disease was significantly higher in single calf than twin calves (18.4 vs. 6.7%), in multiparous than nulliparous group (40.0 vs. 9.9%), in eutocia than dystocia group (20.0 vs. 4.8%), in spring and winter groups than summer and autumn groups (20.3, 22.7 vs. 4.3, 0.0%), and in non-vaccinated than vaccinated group (22.7 vs. 1.6%), respectively (p < 0.05). The rate of mortality was significantly higher when transferred into nulliparous than multiparous (22.3 vs. 0.0%), when were dystocia than eutocia group (71.4 vs. 14.1%), when were non-midwifery than midwifery (45.0 vs. 13.6), when delayed midwifery than earlier midwifery (31.6 vs. 11.5%), and when were non-vaccinated than vaccinated group (28.0 vs. 9.8%), respectively (P < 0.05). The present study suggested that the viability of bovine calves derived from in vitro was affected by the recipient parity, parturition treatment technique and vaccination. This study was supported by the BIO-GREEN 21 PROGRAM.

298 THE INFLUENCE OF DISTINCT CENTRAL BULL STATIONS ON THE IN VITRO EMBRYONIC DEVELOPMENT OF NELORE BULLS

2010 ◽  
Vol 22 (1) ◽  
pp. 305
Author(s):  
A. Renzi ◽  
F. P. Elias ◽  
R. A. Vila ◽  
R. B. Lôbo
Keyword(s):  
Calf Serum ◽  
Cumulus Cells ◽  
In Vitro Production ◽  
Freezing And Thawing ◽  
Chi Square ◽  
Frozen Semen ◽  
Chi Square Test ◽  
Vitro Production ◽  
In Vitro Embryonic Development

Reproductive biotechnology is growing worldwide as one of the most important tools of cattle breeding because it accelerates the process of genetic improvement. Most of the embryos produced are obtained using frozen semen from different AI centers. During freezing and thawing of semen, the sperm can be damaged by the rapid and dramatic changes in the physicochemical conditions that occur during cooling and ice formation. It has previously been described that bad management of frozen semen can result in reduced fertilization. This study investigated the influence of different central bull stations on the development of in vitro-produced bovine embryos. We compared semen of 154 Nelore bulls, used for IVF, from 8 different central bull stations (all of which used the same cryopreservation protocol) in the development of blastocysts. The in vitro production of embryos was performed as described: oocytes were collected from the slaughterhouse and matured in TCM-199 + 10% fetal calf serum (FCS) +0.5 μg mL-1 FSH + 50 μg mL-1 LH+ 1 μg mL-1 estradiol, for 24 hat 38.5°C in 5%CO2 in atmospheric air. Viable spermatozoids were obtained by centrifugation in Percoll gradient (45 and 90%), and used for IVF in a concentration of 2 million spermatozoa per mL in TALP + 10 μg mL-1 of heparin medium. After 12 h, the presumptive zygotes were transferred to a CR2+ 10% FCS medium and co-cultured with cumulus cells. After 168 h of IVF, we evaluated the number and stage of cleaved embryos produced with the semen of each bull. Statistical analyses were performed by using the chi-square test. Our results suggest that there are differences among distinct central bull stations in the proportion of embryos that developed into blastocysts and the different stages they hatched. FAPESP, CNPq, PROEX, FAEPA.

232 ADDITION OF VERY LOW AMOUNTS OF SERUM (ESTRUS COW SERUM) IMPROVES IN VITRO EMBRYO PRODUCTION IN DAIRY CATTLE

2015 ◽  
Vol 27 (1) ◽  
pp. 205 ◽  
Author(s):  
E. Mullaart ◽  
F. Dotinga ◽  
C. Ponsart ◽  
H. Knijn ◽  
J. Schouten
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Calf Serum ◽  
High Serum ◽  
In Vitro Production ◽  
Embryo Production ◽  
Chi Square ◽  
Embryo Yield ◽  
Vitro Production

Improving the efficiency of the in vitro production (IVP) process is very important because it results in more embryos to be used in breeding programs or as commercial service. At CRV, a culture medium consisting of SOF with amino acids and BSA is used. In the past, richer culture media were used with 10% fetal calf serum combined with BRL cell co-culture. Although the efficiency of the IVP process of these media was good, these rather high serum concentrations were quite often related to large offspring syndrome (LOS). The switch to a culture system without serum resulted in a significant reduction in LOS but also in a reduction of embryo yield. The aim of the present study was to investigate the effect of adding low amounts of serum to the culture medium on efficiency of embryo production. Immature cumulus-oocyte complexes (COC) were recovered from ovaries 6 to 8 h upon slaughter. The COC were matured in vitro in TCM199/FCS/LH/FSH supplemented with cysteamine (0.1 mM). Subsequently, matured oocytes were fertilised with frozen-thawed gradient-separated semen and further cultured for 7 days in SOFaaBSA. The SOF medium contained either 0 (control), 0.1, 0.5, or 1.0% oestrus cow serum (ECS). Embryos development was scored at Day 7. Three replicates were performed and results were analysed by chi-square analyses. The results clearly show that adding ECS significantly improved embryo production (Table 1). Interestingly, already very low amounts (0.1%) of serum gave a significant increase in embryo percentage. In conclusion, addition of very low amounts of ECS (0.1%) is beneficial for embryo production, resulting in significantly higher embryo production (from 19 to 27%). In a subsequent field trial with OPU-derived embryos, the effect of addition of 0.1% ECS on birth weight (LOS) of the calves has to be investigated. Table 1.Percentage of blastocysts at Day 7 after culture in SOF medium with different amounts of serum

Reduced polyspermic fertilization of porcine oocytes utilizing elevated bicarbonate and reduced calcium concentrations in a single-medium system

2003 ◽  
Vol 15 (4) ◽  
pp. 249 ◽  
Author(s):  
J. R. Herrick ◽  
M. L. Conover-Sparman ◽  
R. L. Krisher
Keyword(s):  
Embryonic Development ◽  
Blastocyst Stage ◽  
In Vitro Production ◽  
High Incidence ◽  
Porcine Embryo ◽  
Medium System ◽  
Epidermal Growth ◽  
Vitro Production ◽  
Single Medium

The development of efficient systems for in vitro production of porcine embryos has been hampered by a high incidence of polyspermic fertilization. A recently developed single-medium system for porcine in vitro maturation (IVM), IVF and in vitro embryo culture (IVC) (Purdue Porcine Medium; PPM) was modified with elevated bicarbonate (44 mM) and reduced calcium concentrations (1.7 mM) for IVF (PPMfert.2). Oocyte penetration was evaluated after maturation in PPMmat (0.5 mg mL−1 hyaluronan, 0.6 mM cysteine, 10 ng mL−1 epidermal growth factor (EGF), 0.1 U mL−1 porcine LH and FSH, and 1 × Minimal Essential Medium (MEM) vitamins) and fertilization (5 h with 5 × 105 sperm mL−1) in either PPMfert.2 or mTBM (20 mM Tris, 0.0 mm bicarbonate, 7.5 mM calcium). Embryonic development (cleavage and blastocyst stages) was assessed after culture in PPM1 and PPM2. Although penetration was lower in PPMfert.2 (69.9%) compared with mTBM (83.9%), 48.8% of penetrated oocytes were fertilized normally in PPMfert.2 compared with only 27.8% normal fertilization in mTBM. More oocytes cleaved in PPMfert.2 (77.9% v. 53.7%), but development to the blastocyst stage was not different between treatments (14.1% v. 14.3%). Further work is needed to improve embryonic development, but reduced polyspermic penetration is an important step in the optimization of the PPM system for in vitro porcine embryo production.

scholarly journals In vitro production of cattle blastocysts in chemically defined medium with or without insulin supplementation

1996 ◽  
Vol 5 (5) ◽  
pp. 509-514 ◽  
Author(s):  
Kristiina Bredbacka ◽  
Peter Bredbacka
Keyword(s):  
Bovine Serum Albumin ◽  
Culture Medium ◽  
Defined Medium ◽  
Blastocyst Stage ◽  
Chemically Defined Medium ◽  
In Vitro Production ◽  
Cell Numbers ◽  
Vitro Production ◽  
Bovine Oocytes

In this study we evaluated the use of a chemically defined medium in the production of blastocysts from bovine oocytes fertilized in vitro. As culture medium we used CRI-PVP, a modification of CRlaa medium with bovine serum albumin replaced by polyvinylpyrrolidone. After 168 h of culture (192 h after insemination) 8.7%, 10.5 and 12.8% of the cleaved embryos developed to the blastocyst stage in the presence of 0, 2 or 200 nM insulin, respectively. The supplementation of 200 nM insulin tended to increase cell numbers in morulae and blastocysts (P=0.10). It is concluded that CRI-PVP can be used as a chemically defined medium in the production of blastocysts from bovine 1-cell embryos. However, further modifications are needed, and the insulin concentrations used may be below the optimum for blastocyst production.

135 SHORT-TERM CRYOPRESERVATION OF VITRIFIED MOUSE MORULAE AT - 79°C

2007 ◽  
Vol 19 (1) ◽  
pp. 185
Author(s):  
Y. Takagi ◽  
M. Shimizu ◽  
M. Morimura ◽  
S. Yokomizo ◽  
K. Hara ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Blastocyst Stage ◽  
Control Group ◽  
Embryo Viability ◽  
Chi Square ◽  
Significant Difference ◽  
Morula Stage ◽  
Chi Square Test ◽  
Student’S T

Embryos of various species are successfully vitrified and cryopreserved in liquid nitrogen (&lt;−150°C). Like the preservation of frozen somatic cells cooled by dry ice (−79°C), the cryopreservation of embryos at −79°C is useful for a reduction in the shipping costs. The purpose of this study was to evaluate the effect of the cryopreservation period at −79°C on the in vitro embryo viability of vitrified mouse morulae after thawing. Morula-stage mouse embryos were collected from superovulated ICR donors 70 h after hCG injection. The embryos were exposed first to 5% DMSO + 5% ethylene glycol (EG) in Dulbecco's PBS + 20% FCS (mPBS) for 2 min, and then equilibrated for 20–30 s in a vitrification solution composed of 10% DMSO + 10% EG + 0.6 M sucrose in mPBS. The embryos were loaded onto cryoloops (Lane et al. 1999 Nat. Biotech. 17, 1234–1236) and plunged directly into liquid nitrogen. The cryoloops were placed in 1.2-mL cryotubes and stored in a −79°C freezer for 1–7 days. The embryos were warmed by passing through 4 dilution media and rinsed with mWM culture medium. They were then cultured at 37°C in 5% CO2 for 44 h. Non-cryopreserved embryos and embryos cryopreserved in liquid nitrogen served as controls. Data were analyzed by the chi-square test and the Student's t-test. Results are shown in Table 1. There was no significant difference (P &gt; 0.01) in the developmental abilities to the blastocyst stage of the vitrified embryos that were cryopreserved at −79°C for 1 day, 3 days, and 5 days, the embryos cryopreserved in liquid nitrogen, and the non-vitrified control. The blastocyst rate of embryos was significantly lower (P &lt; 0.01) for the Day 7 group than for the control group. The cell numbers of blastocysts were significantly lower (P &lt; 0.01) for the Day 1, Day 3, Day 5, and Day 7 groups than for the control group. This study suggests that vitrified mouse morulae can be successfully cryopreserved at −79°C for 5 days. Table 1. Effect of the cryopreservation period on the viability of vitrified mouse morulae preserved at −79°C

163IMPROVEMENT OF IN VITRO PRODUCTION OF PIG EMBRYOS BY SYNCHRONISATION OF OOCYTE MEIOTIC MATURATION WITH CYCLOHEXIMIDE

2004 ◽  
Vol 16 (2) ◽  
pp. 204 ◽  
Author(s):  
J. Ye ◽  
K.H.S. Campbell ◽  
M.R. Luck
Keyword(s):  
Cumulus Cells ◽  
Treated Group ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Meiotic Maturation ◽  
In Vitro Production ◽  
Maturation Medium ◽  
Pre Treatment ◽  
Vitro Production

It is suggested that the relatively high rates of polyspermic fertilization and poor development of pig embryos produced in vitro are caused by asynchronous oocyte maturation. We have recently shown that pre-treatment of pig oocytes with cycloheximide (CHX) is an efficient way of synchronizing their meiotic maturation in vitro. However, it is not known whether this procedure affects fertilization or further development. The present study examined the effects of CHX-synchronised meiotic maturation on subsequent embryo development and the response to FSH. Pig ovaries were collected from a local abattoir. Cumulus-oocyte complexes (COCs) were aspirated from 3–5mm diameter follicles with a translucent appearance and extensive vascularization. COCs were first pre-incubated in defined maturation medium (DM; M199 with Earle’s salts, 25mM HEPES and sodium bicarbonate, 3mM L-glutamine, 0.1% (w/v) BSA, 0.57mM cysteine, 10ngmL−1 EGF, 0.2μgmL−1 pLH, 100μmL−1 penicillin and 0.1mgmL−1 streptomycin) or in DM supplemented with 50ngmL−1 pFSH (DMF) and 5μgmL−1 CHX for 12h. COCs were then further cultured in the same DM without CHX for 24–30h or in DMF for 36h. For controls, COCs were cultured conventionally in DM for 42h or DMF for 48h. After removal of cumulus cells, all cultured oocytes were inseminated with ejaculated sperm at a final concentration of 300000mL−1 for 6h. The IVF medium was modified Tris-buffered medium containing 0.1% BSA, 20μM adenosine and 0.2mM reduced glutathione. Putative embryos were cultured in NCSU23 without glucose but supplemented with 4.5mM Na lactate and 0.33 mM Na pyruvate for 2 days. Cleaved embryos were further cultured in normal NCSU23 for 4 days. IVM and IVF were performed in 5% CO2 in air and IVC in 5% CO2, 5% O2, 90% N2, all at 39°C and 95% RH. Three replicates with DM, with or without CHX, and one with DMF, with or without CHX, were performed with 30–50 oocytes in each replicate. Statistical comparisons were by t-test. The result with DM showed that the rate for normal cleavage at 2 days after insemination of CHX-treated oocytes (40.6±3.8%) was similar to that of controls (40.4±3.5%). However, the proportion developing to healthy blastocysts at Day 6 was significantly higher in the CHX-treated group (16.9±1.2%) than in controls (9.6±1.3%; P&lt;0.05). A significantly higher number of Day 2-cleaved embryos from CHX-treated oocytes developed to the day 6 blastocyst stage compared with controls (44.7±5.0% and 22.3±2.4%, respectively; P&lt;0.05). Supplementation of the basic maturation medium with pFSH increased the rate of cleavage in both CHX-treated oocytes (73.2%) and controls (76.9%) and increased the proportions developing to healthy blastocysts at Day 6 (CHX-treated: 39.0%; control: 11.5%). We conclude that oocytes pre-treated with CHX retain their developmental competence and that meiotic synchronization with CHX improves the efficiency of in vitro production of pig embryos. (Supported by BBSRC 42/S18810.)

235 A COMPARISON OF PARTHENOGENETIC DEVELOPMENT OF PORCINE OOCYTES SYNCHRONISED DURING MATURATION BY CYCLOHEXIMIDE OR cAMP

2009 ◽  
Vol 21 (1) ◽  
pp. 215
Author(s):  
W. C. Chen ◽  
J. Zhu ◽  
P. Fisher ◽  
D. Amarnath ◽  
K. H. S. Campbell
Keyword(s):  
Time Window ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Total Cell ◽  
Blastocyst Formation ◽  
Cleavage Rate ◽  
Chi Square ◽  
Parthenogenetic Development ◽  
High Level

In vitro maturation of porcine oocytes is characterized by a high level of asynchrony between oocytes. Previous studies reported that cycloheximide (CHX) and 3′, 5′-cyclic AMP (cAMP) synchronize porcine oocytes and improve development to blastocyst stage following IVF or have been used for somatic cell nuclear transfer (SCNT) (Ye et al. 2005 Biol. Reprod. 72(2), 399–406; Betthauser et al. 2000 Nat. Biotechnol. 18(10), 1055–1059). We previously reported that cAMP was more effective than CHX in synchronizing porcine oocyte maturation, producing MII oocytes in a shorter time window and providing a more homogenous population for future SCNT studies (Chen et al. 2008 SRF conference, 2008 abst, p34). Here we compared parthenogenetic development of porcine oocytes synchronized by these two treatments. Selected cumulus–oocyte complexes (COC) obtained from slaughtered gilts were randomly divided into three groups and cultured at 39°C, 5% CO2 in air in modified NCSU-23 medium (with 1 μm glutathione, 1 mm cysteine, 5 mg L–1 insulin, 10 ng mL–1 epidermal growth factor, 10% (v/v) porcine follicular fluid, 1% essential and 0.5% nonessential amino acids) ± hormones (10 IU mL–1 PMSG and 10 IU mL–1 hCG): (1) with hormones for the first 22 h and then without hormones until 44 h; (2) with hormones and 5 μg mL–1 CHX for 12 h, and then with hormones but no CHX until 44 h; (3) with hormones and 1 mm cAMP for 22 h, and then without hormones and cAMP until 44 h. Parthenogenetic development of cycloheximide and cAMP treated oocytes was compared by cleavage rate at 48 h postactivation (hpa) and blastocyst formation at 168 hpa. No significant differences were observed in the frequency of cleavage (96.7 ± 2.1% v. 81.4 ± 11.6% v. 84.5 ± 5.7%), development to blastocyst (28.3 ± 11.4% v. 27.1 ± 5.7% v. 32.8 ± 5.3%) between control, CHX or cAMP treated oocytes, respectively (chi-square test, P > 0.05). However, total cell number was significantly higher in the CHX group than cAMP group (42.7 ± 4.1 v. 31.8 ± 2.0, respectively; t-test, P < 0.05). The results demonstrate that synchronization of porcine oocytes by treatment with CHX or cAMP does not affect subsequent parthenogenetic development if judged by the blastocyst formation, although the meaning of the difference of total cell numbers between CHX and cAMP treatments is still unclear.

243 IN VITRO PRODUCTION OF LLAMA EMBRYOS BY IVF OR ICSI

2007 ◽  
Vol 19 (1) ◽  
pp. 237
Author(s):  
P. A. Conde ◽  
C. Herrera ◽  
M. G. Chaves ◽  
S. M. Giuliano ◽  
A. Director ◽  
...  
Keyword(s):  
Defined Medium ◽  
Blastocyst Stage ◽  
In Vitro Production ◽  
Blastocyst Development ◽  
Chi Square ◽  
Vitro Fertilization ◽  
South American Camelids ◽  
Lama Glama ◽  
Initial Description

Interest in South American camelids has increased in the last few years. Assisted reproduction techniques, such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) with epididymal spermatozoa, have shown poor results in these species (Tibary et al. 2005 Theriogenology 64, 618–638). The aim of the present study was to compare the efficacy of IVF vs. ICSI for in vitro embryo production in llama (Lama glama) using oocytes collected from ovarian follicles of different sizes. A total of 193 oocytes were collected from 223 follicles aspirated from 21 adult females by flank laparotomy after ovarian stimulation. Before aspiration, the diameter of each follicle was measured, and oocytes from each female were randomly assigned to either IVF or ICSI treatment. Semen samples were collected by electroejaculation and incubated in 25% (v/v) collagenase solution at 37°C to reduce viscosity. For IVF, spermatozoa were either non-treated or treated with heparin, penicillamine, and hypotaurine as capacitating agents. For ICSI, some oocytes were activated immediately after sperm injection with 5 µM of ionomycin for 10 min and 2 mM of 6-DMAP for 3 h, while others were subjected only to sperm injection. Spermatozoa used for ICSI were not treated with capacitating agents. All presumptive zygotes were cultured in SOFaas for 8 days. The percentage of total oocytes and mature (MII) oocytes recovered from follicles &lt;7 mm and &gt;7 mm in diameter were compared in each female. The proportion of oocytes inseminated via IVF and ICSI that cleaved and developed to the blastocyst stage was compared. The proportion of total oocytes, MII-oocytes, cleaved embryos, and blastocysts were compared between treatments by chi-square and Fisher's tests. The percentages of total (77/100; 77%) and MII (9/31; 29%) oocytes collected from &lt;7 mm follicles were significantly lower than those of total (116/126; 92%) and MII (43/55; 78%) oocytes collected from &gt;7 mm follicles (P &lt; 0.01). The highest cleavage rates were observed in oocytes collected from follicles &gt;7 mm in diameter and fertilized by IVF with (56%) or without (50%) capacitating agents; these rates were significantly different from those of the other treatments (P &lt; 0.05, Table 1). Further studies will determine if the present results can be obtained with a higher number of oocytes. The results of the present study provide the first demonstration that Lama glama embryos can be produced in vitro using fresh semen. In addition, we have provided the initial description of blastocyst development after culture of ICSI-derived embryos in a defined medium. Table 1.Cleavage and blastocyst formation in different-sized llama oocytes inseminated via IVF or ICSI

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