298 SPERM CAPACITATED WITH CALCIUM IONOPHORE AS A VECTOR FOR IN VITRO PRODUCTION OF BOVINE TRANSGENIC EMBRYOS

2006 ◽  
Vol 18 (2) ◽  
pp. 256
Author(s):  
R. Simões ◽  
M. P. Milazzotto ◽  
C. Yamada ◽  
W. B. Feitosa ◽  
A. R. S. Coutinho ◽  
...  

Production of transgenic mouse embryos by microinjection is a well established and successful technique. However, when microinjection protocols were used for bovine, the amount of the oocyte lipid content did not allow the production of bovine transgenic embryos. Sperm-mediated gene transfer (SMGT) is an alternative for this species because it has lower cost and does not require microinjection handling. One of the procedures to introduce exogen DNA into oocytes is by means of sperm capacitated with calcium ionophore (CaI). The aim of this work was to evaluate different CaI concentrations ([CaI]), sperm incubation times with CaI (tCa), and incubation times of sperm capacitated with DNA (tDNA) (EYFP; Clontech, Palo Alta, CA, USA) to establish a satisfactory method for IVP of bovine transgenic embryos. Slaughterhouse oocytes with compact cumulus and uniform ooplasm were in vitro maturated in TCM-199 medium + 10% FCS + FSH + hCG + estradiol (E2) + piruvate + gentamicin under 5% CO2 in air, at 39�C and high humidified atmosphere for 24 h. Semen was thawed in a water bath at 37�C for 30 s and separated by Percoll gradient (45/90%) at 600g for 30 min. After this procedure, sperm cells were washed in TALP-semen medium by centrifugation at 200g for 5 min at room temperature. Supernatant was removed and capacitation (5 � 106 spermatozoa/group) was induced with CaI (250 nM or 500 nM for 1 or 5 min). Capacitated sperm cells were incubated with 500 ng/mL DNA for 1 or 2 h. Nontreated spermatozoa were used as control group. Sperm cells (1 � 105) were used to inseminate 20 oocytes/90 mL microdroplets for 18 h. The presumptive zygotes were co-cultured in SOFaa medium with a granulosa cell monolayer under high humidified atmosphere, at 39�C and 5% CO2 in air. Blastocyst rates were analyzed by ANOVA. Independent variables were replicate, [CaI], tCa, tDNA, and the double and triple interactions among the last three variables; when appropriate, means were compared by orthogonal contrasts. There was [CaI] � tCa � tDNA interaction for blastocyst rate (P < 0.02). Treatments with 250 nM ([CaI]), 5 min (tCaI), and 1 h (tDNA) or 500 nM ([CaI]), 1 min (tCaI), and 1 h (tDNA) resulted in 36.1% and 37.4% blastocyst rates, respectively, similar to the control group (30.5%; P > 0.4). These results demonstrated that it is possible to capacitate spermatozoa with CaI to produce transgenic embryos, without alteration of blastocyst rate. This work was supported by FAPESP 03/08542-5 and 03/07456-8.

2007 ◽  
Vol 19 (1) ◽  
pp. 320
Author(s):  
R. Simões ◽  
M. Binelli ◽  
A. C. Nicacio ◽  
M. P. Milazzotto ◽  
W. B. Feitosa ◽  
...  

There are many methods to produce transgenic animals, although when considering bovine species, those methods offer low repeatability, high costs, and low transgene integration efficiency. To overcome these difficulties, sperm mediated gene transfer (SMGT) could be used as an alternative to produce transgenic embryos. This technology allows carrying exogenous DNA into the oocyte during the fertilization period, once spontaneous binding exists between spermatozoa and exogenous DNA. The aim of this study was to compare 4 methods for incorporating DNA into sperm cells—sperm incubation, capacitation, electroporation, and lipofection—to verify the efficiency of embryo production with exogenous DNA, employing spermatozoa as a vector. Cumulus–oocyte complexes (COCs) from abattoir-derived bovine ovaries were randomly divided into 5 groups (4 experimental groups: sperm incubation, sperm capacitation with calcium ionophore, electroporation, and lipofection; and 1 control group). In vitro maturation was performed in TCM-199 medium supplemented with 10% FCS, sodium pyruvate, gentamycin, FSH, hCG, and estradiol in an incubator at 39�C, in an atmosphere of 5% CO2 in air and high humidity for 24 h. After Percoll gradient (45/90%) separation at 600g for 30 min, spermatozoa were washed in Talp Semen medium (200g for 5 min). For in vitro fertilization (IVF), 5 � 106 spermatozoa were used to inseminate microdroplets with 20 matured oocytes from all groups: incubation with exogenous DNA for 1 h, sperm capacitation (250 nM of calcium ionophore) for 5 min followed by sperm incubation for 1 h, electroporation (500V), and lipofection (Effectene�; Qiagen, Mississauga, Ontario, Canada). The EYFP-Nuc plasmid (500 ng mL-1; Clontech, Mountain View, CA, USA) was used as exogenous DNA. Oocytes inseminated with non-treated sperm were considered as the control group. The presumptive zygotes were co-cultured with a granulosa cell monolayer in SOFaa medium in an incubator at 39�C, with an atmosphere of 5% CO2 in air and high humidity. The blastocyst rate was analyzed by ANOVA. Embryos from all experimental and control groups were subjected to PCR to detect internalized EYFP, using primers specific to this exogenous DNA, and considering positive embryos those that showed a fragment of 440 bp after electrophoresis. The fragment of 440 bp from positive embryos was sequenced to check correspondence to the EYFP. Electroporation (17.95%) and sperm capacitation (15.12%) were more efficient for EYFP-positive embryo production when compared to the lipofection protocol (6.25%). Sperm incubation (12.5%) did not show a significant difference from the other groups. Sequenced PCR-positive products for EYFP showed 100% homology with nucleotides of EYFP at GenBank. In conclusion, it is possible to use SMGT to deliver exogenous DNA into an oocyte at the time of IVF. This work was supported financially FAPESP 03/08542-5 and 03/07456-8.


2007 ◽  
Vol 19 (1) ◽  
pp. 147
Author(s):  
H. T. Lee ◽  
J. M. Jang ◽  
S. H. Lee ◽  
M. K. Gupta

In vitro production of cloned porcine embryos by somatic cell nuclear transfer (SCNT) has become routine in several laboratories but the efficiency and quality of the resultant blastocysts remains sub-optimal. Cloned porcine blastocysts show low cell number, high fragmentation rate, and apoptosis which results in lower pregnancy rates upon embryo transfer. Earlier we reported that supplementation of culture media with amino acids benefit pre-implantation embryo development of in vivo- as well as in vitro-fertilized porcine embryos (Koo et al. 1997 Theriogenology 48, 791–802). This study evaluated how exogenous amino acids could affect pre-implantation development and quality of cloned or parthenogenetic porcine embryos. The effects of commercially available amino acids, referred to as Eagle&apos;s non-essential amino acids (NEAA), added or not added (control) to NCSU23 medium containing fatty acid-free BSA were studied. Oocytes recovered from abattoir-derived prepubertal porcine ovaries were matured in vitro and parthenogenetically activated (PA) or nuclear-transferred with fetal fibroblasts (SCNT), as described earlier (Uhm et al. 2000 Mol. Reprod. Dev. 57, 331–337). At 168 h post-activation, blastocysts were harvested for assessment of embryo quality by TUNEL labeling, Hoechst 33342 staining, and gene expression analysis. Results showed that, in the PA group, the cleavage rate was not affected by the supplementation of NEAA. However, the blastocyst rate was significantly improved when NEAA was present in the medium compared to that of the control group (38.9 &plusmn; 0.3 vs. 27.5 &plusmn; 0.3&percnt;, respectively) throughout the culture period. The supplementation during the pre-compaction period alone gave better results than during the post-compaction period alone (59.5 &plusmn; 0.9 vs. 33.4 &plusmn; 0.3&percnt;, respectively). In the SCNT group, however, both cleavage (73.6 &plusmn; 0.2 vs. 64.2 &plusmn; 0.4&percnt;) and blastocyst rate (18.7 &plusmn; 0.2 vs. 13.8 &plusmn; 0.3&percnt;) were improved by NEAA supplementation. Furthermore, these blastocysts had higher hatching ability (30.0 &plusmn; 1.8 vs. 14.6 &plusmn; 4.9&percnt;) than those of control group (P &lt; 0.05). Supplementation of NEAA also increased the mean nuclei number of PA-derived (76.1 &plusmn; 4.9 vs. 66.5 &plusmn; 3.3) as well as SCNT-derived (43.1 &plusmn; 2.6 vs. 31.8 &plusmn; 1.9) blastocysts and reduced the time during which blastocysts formed. TUNEL assay revealed that incidence of nuclear fragmentation and apotosis was reduced by NEAA. Real-time qRT-PCR for Bax and Bcl-XL transcripts revealed that the relative abundance of Bax was reduced while that of Bcl-XL was increased. These effects were more pronounced when NEAA was present during the pre-compaction period alone. Thus, our data suggest that NEAA improves the yield and quality of cloned porcine embryos by enhancing blastocyst expansion and positively modulating the total cell number and apoptosis. These data may have implications for understanding the nutritional needs of cloned porcine embryos produced in vitro and for optimizing the composition of culture media to support their development. This work was supported by the Research Project on the Production of Bio-Organs (No. 200503030201), Ministry of Agriculture and Forestry, Republic of Korea.


2016 ◽  
Vol 28 (2) ◽  
pp. 256
Author(s):  
L. M. Vieira ◽  
G. A. Bó ◽  
R. J. Mapletoft

In vitro embryo production (IVP) is an important tool to enhance genetic gain in cattle. However, oocyte quality is a limiting factor for the success of IVP programs in high-producing donors. A series of studies using protocols for follicular wave synchronization and superstimulation before ovum pickup were performed to improve the efficiency of ovum pickup and in vitro production in dairy cattle. The first study evaluated superstimulation with FSH (Folltropin-V®) before ovum pickup in lactating (n = 15) and non-lactating (n = 15) Holstein donors in a crossover design. Cows underwent synchronization of follicle wave emergence (FWE) and at the expected time of FWE, the FSH group received a total dosage of 200 mg of FSH in 4 decreasing doses 12 h apart; controls received no FSH, and ovum pickup was conducted 72 h after the expected FWE in all cows. The FSH-treated cows had a higher (P < 0.01) percentage of medium-sized follicles (6 to 10 mm) at the time of ovum pickup (55.1%) than control cows (20.8%) as well as lower cumulus‐oocyte complexes (COC) recovery rates (60.0 v. 69.8%, respectively; P = 0.002). However, FSH-treated cows had a higher blastocyst production rate (34.5 v. 19.8%; P < 0.01) and more transferable embryos per ovum pickup session (3.0 ± 0.5 v. 1.8 ± 0.4; P = 0.02). Subsequent trials evaluated plasma FSH profiles in 23 heifers and in vitro production following ovum pickup in 90 non-lactating Holstein donors superstimulated with a single IM injection of FSH in 0.5% hyaluronan (HA; MAP-5®, 50 mg). Controls received no treatment, while the F200 group received 200 mg of FSH in 4 decreasing doses 12 h apart. The F200HA and F300HA groups received 200 or 300 mg of FSH in 5 or 7.5 mL, respectively, of 0.5% HA by a single IM injection. Circulating FSH area under curve (AUC) in FSH-treated animals was greater than in the control group (P = 0.02). Although the AUC for F200 group did not differ from HA groups (P = 0.56), the total period of time plasma FSH levels were elevated was greater than in the HA groups (P < 0.01). In the IVP trial, FSH-treated cows had a greater proportion of medium-sized (6–10 mm) follicles than controls (P < 0.001). Also, numbers of follicles (P = 0.01) retrieved (control: 13.1 ± 1.0; F200: 16.5 ± 1.2; F200HA: 19.5 ± 2.1; F300HA: 15.4 ± 1.4; P = 0.01) and blastocysts produced per ovum pickup session (control: 2.4 ± 0.5; F200: 3.7 ± 0.7; F200HA: 4.7 ± 0.7; F300HA: 3.1 ± 0.6; P = 0.06) were greater in cows receiving FSH, regardless of treatment. Cows in the F200HA group had a greater recovery rate (P = 0.009), number of COC cultured (P = 0.04), and blastocysts per ovum pickup session (P = 0.06) than cows in the F300HA group. In conclusion, superstimulation of Holstein donors before ovum pickup increased the efficiency of in vitro production. Additionally, a single IM dose of FSH in 0.5% HA resulted in similar plasma FSH profiles to twice-daily FSH treatment. Non-lactating donors treated with FSH produced more embryos per ovum pickup session regardless of FSH treatment. Lastly, all in vitro-produced endpoints were greater following a single dose of 200 mg of FSH in 0.5% HA than 300 mg of FSH in 0.5% HA.


2004 ◽  
Vol 16 (2) ◽  
pp. 15 ◽  
Author(s):  
Matthew B. Wheeler ◽  
Sherrie G. Clark ◽  
David J. Beebe

Several modifications have been made to in vitro production (IVP) systems to allow more efficient production of viable porcine embryos. Although in vitro production of pig embryos has been studied for over 30 years, the overall blastocyst production rate remains low. The low blastocyst rate is due to several factors, including polyspermic oocyte penetration, low rate of male pronucleus formation and less than optimal in vitro culture systems. These conditions are all inherent problems in porcine IVP and many of the mechanisms involved remain unknown. Considerable research has examined culture medium and the techniques used during the various stages of in vitro production. However, changes to the physical culture system used during IVF have remained unchanged until recently. The present paper will summarise selected developments in fertilisation and embryo culture media composition and focus on the development of modified equipment to improve the conditions used during the IVP of porcine oocytes and embryos.


Author(s):  
Alan da Silva LIRA ◽  
Ricardo de Macedo CHAVES ◽  
Felipe de Jesus MORAES JUNIOR ◽  
Sergio Henrique COSTA JUNIOR ◽  
Brenda Karine Lima do AMARAL ◽  
...  

ABSTRACT We aimed to assess the effects of melatonin in the in vitro production of bovine embryos. Our experiment was conducted at the Laboratório de Reprodução Animal of the Universidade Estadual do Maranhão. The cumulus-oocyte complexes (COCs) were distributed among treatments at concentrations of 0, 10-1, 10-3 and 10-5 µMol/L melatonin. Our experiment was further divided into two: the first was to assess the effect of different concentrations of melatonin (treatments) on the maturation rate of COCs, and the second was to assess the effects of melatonin treatments on the in vitro production of bovine embryos. The results from the first experiment demonstrated no significant difference between the in vitro maturation rate of the cultivated COCs in treatments with melatonin. In the second experiment, however, melatonin treatments yielded statistically higher cleavage, morula and blastocyst rates in the 10-5 µM group (52.9%, 52.9%, and 35.3%, respectively), and lower rates in the 10-1 µM group (19.5%, 19.5% and 7.8%, respectively), compared to the others. The control group (no melatonin) and the 10-3 µM group showed similar results. We concluded that supplementation of melatonin in the in vitro maturation medium resulted in no improvement in the oocyte maturation rate, but in the in vitro production of embryos at different concentrations, the 10-5 µM group displayed better results, but with no improvement in the variables (P < 0.05).


SPERMOVA ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 67-72
Author(s):  
Mijail Contreras Huamani ◽  
◽  
Mary Naveros ◽  
Cesar Olaguivel

The objective of this research was to evaluate the effect of the use of two sperm selection techniques for in vitro production of alpaca embryos. The ovaries and testis were collected from the local slaughterhouse and transport to 37 ° C in saline solution (0.9%) supplemented with gentamicin. Quality I, II and II oocytes were incubated in a maturation medium for 32 h at 38.5 ° C and 5% O2 and 5% CO2. For in vitro fertilization, sperm from the epididymis were selected using the Percoll gradient and Swim up technique. 18h after the oocytes were incubated with the sperm, these were denuded from the cumulus cells and cultured in SOFaa culture medium for 7 days. Morula and blastocyst rate and their morphological quality are evaluated at day 7 of culture. From a total of 370 ovaries, 1,137 oocytes were recovered, making an average of 3.6 oocytes / ovary. After the maturation and fertilization process and in vitro culture, the blastocyst rate was 8.43 ± 6.04% and 3.89 ± 1.75%, for oocytes fertilized with sperm selected with Percoll gradient and Swim up, respectively, not finding significant statistical differences (p> 0.05), between the groups. In conclusion, the in vitro fertilization of alpaca oocytes with spermatozoa selected with two selection techniques (percoll and swim up) did not significantly influence the quantity and quality of morulae and blastocysts at day 7 of embryo culture.


2020 ◽  
Vol 6 (10) ◽  
pp. 5823-5832
Author(s):  
Mina Vardiani ◽  
Marefat Ghaffari Novin ◽  
Morteza Koruji ◽  
Hamid Nazarian ◽  
Ellen Goossens ◽  
...  

2020 ◽  
Vol 22 (4) ◽  
pp. 751-764
Author(s):  
L. V. Krechetova ◽  
V. V. Vtorushina ◽  
E. V. Inviyaeva ◽  
L. V. Vanko ◽  
M. A. Nikolaeva ◽  
...  

We aimed  for assessing effects of immunocytotherapy upon  the subpopulations of CD4+CD25highFoxP3+ cellswithnaturalregulatoryactivityandactivatedTh17cellswiththeCD4+CD25highRORγt+ phenotype, as well as in vitro production of cytokines in mitogen-stimulated cells from  peripheral blood  in the patients with idiopathic habitual miscarriage (IHM). The study group consisted of 33 patients with IHM who became pregnant after a pre-gestational alloimmunization. In 27 patients, the pregnancy was prolonged to the  full term  and  ended  with the  birth  of viable babies,  in six cases it was terminated before  12 weeks of gestation. Before  administration of immunocytotherapy (ICT), 19 patients were examined, of them  16 after alloimmunization outside of pregnancy, 17 at 5-6 and 8-9 weeks of pregnancy. Eleven patients were immunized at 12 weeks of pregnancy. In the control group,  12 fertile women  outside  pregnancy and 10 women  at 12 weeks of physiological pregnancy were examined. The proportion of FoxP3+ and RORγt+ cells with the CD4+CD25high phenotype was evaluated among  T-lymphocytes from peripheral blood,  as well as content of proinflammatory cytokines (IFNγ,  TNFα, IL-1β, IL-2, IL-5, IL  -6,  IL-8, IL-12p70) and  anti-inflammatory factors  (IL-4, IL-10), as well as IL-17  amounts.We have found  that,  following pre-gestational alloimmunization, the women  who lost this pregnancy, had a  low  level  of  FoxP3+Тregs that  suppress  pro-inflammatory Th17-dependent  reactions, however, without changing levels of activated Th17  cells (CD4+CD25highRORγt+   lymphocytes). These  facts,  along  with  high in vitro production of IL-17  by peripheral blood cells at the terms of 5-6 weeks of gestation, suggest that,  after pre-gestational alloimmunization in women  with miscarriage, a predilection is formed  to pro-inflammatory cytokine production. However, at the 5-6 week-period, it is realized  not in the Th1 direction of, but towards Th17 response, and a low level of CD4+CD25highRORγt+ cells may reflect an increased migration of Th17 cells from peripheral blood to the uterine endometrium.Thus,  we have shown  the  effect of immunocytotherapy upon  subpopulational composition of peripheral blood  lymphocytes and  the  cytokine profile,  as well as upon  the  course  of first trimester and  outcomes of pregnancy in women  with idiopathic habitual miscarriage.


2007 ◽  
Vol 19 (1) ◽  
pp. 141
Author(s):  
I. S. Hwang ◽  
H. J. Moon ◽  
J. H. Shim ◽  
M. R. Park ◽  
D. H. Kim ◽  
...  

In vitro production of the pig embryo is very important as an initial step to improve its application in biotechnology. The in vitro production system for pig embryos, however, has been plagued by the high incidence of polyspermy and poor embryo quality. The present study was conducted to examine the relationship between apoptosis and osmolarity of culture medium in pre-implantation development of porcine NT and IVF embryos. Oocytes were aspirated from ovaries collected from a local abattoir, and then matured in TCM-199 for 40–44 h. Fresh semen was diluted and equilibrated at 16�C. The final concentration of motile spermatozoa was adjusted to 5 � 105 cells/mL in fertilization medium. Fetal fibroblasts were prepared from a 35-day-old porcine fetus for use as donor cells. The NT and IVF embryos were cultured in PZM-3 supplemented with 0.05 M sucrose or a final concentration of 138 mM NaCl (280–320 mOsmol) for the first 2 days, and then cultured in PZM-3 (250–270 mOsmol) for the remaining days. For the control, NT and IVF embryos were cultured in PZM-3 for whole culture period. After 6 days of culture, the developmental ability of embryos, total cell numbers, ratio of ICM/TE, and apoptosis of cells in blastocysts were examined. The developmental rate to the blastocyst stage of NT embryos was significantly higher (P &lt; 0.05) in the sucrose and NaCl groups than in the control [14.7% (21/153) and 21.7% (34/154) vs. 11.5% (18/152), respectively]. Also, the developmental rate to the blastocyst stage after IVF was slightly higher in embryos cultured in the medium supplemented with NaCl than in the control group [21.8% (49/235) and 26.4% (61/237) vs. 18.9% (44/247)]. For apoptosis, both NT and IVF blastocysts produced in the sucrose and NaCl groups showed slightly lower frequency of apoptosis compared to that of the control (2.2% and 2.8% vs. 3.1% for NT; 0.9% and 0.7% vs. 1.1% for IVF). These studies suggest that the high osmolarity in the early embryo culture stage could enhance the in vitro development of both porcine NT and IVF embryos to the blastocyst stage and could reduce the apoptosis of cells.


2010 ◽  
Vol 22 (1) ◽  
pp. 236
Author(s):  
T. A. D. Tetzner ◽  
N. Z. Saraiva ◽  
C. S. Oliveira ◽  
S. C. Méo ◽  
M. M. Souza ◽  
...  

Embryo quality is influenced by culture conditions, which affect IVM, IVF, and IVC rates. One of the most efficient ways to evaluate the embryonic quality of IVP blastocysts is by differential staining of inner cell mass (ICM) and trophoblast (TF). Bovine embryos of superior quality should present the total number of cells close to the number of cell cycles (Neuber et al. 2002 Theriogenology 57, 2193-2202). In this study, we analyzed the effects of fetal bovine serum (F) and bovine serum albumin (B) replacement for ovalbumin (O) on nuclear maturation, cortical granule migration, pronuclear development, blastocyst rates, and differential staining of ICM and TF in Day 7 blastocysts. The treatment groups were named as follows: the first letter is the protein source used for IVM, the second for IVF, and the third for IVC. When 2 protein sources were used in the same step, the plus symbol (+) was used. The oocytes were IVM in TCM-199, supplemented with the following: 10% F, or 4 mg mL-1 B, or 4 mg mL-1 O, and 1.0 Âμg mL-1 of FSH, 50 Âμg mL-1 of hCG, 1.0 Âμg mL-1 of estradiol, 0.2 mM sodium pyruvate, and 83.4 Âμg mL-1 of amikacin. IVF was accomplished in TALP-IVF medium, with 0.2 mM pyruvate, 83.4 Âμg mL-1 of amikacin, and 6 mg mL-1 B or O. IVC was in SOF, with F, B, or O. The control group (CONT) consisted of the treatment FBF + B. Pronuclear development was compared by the chi-square test, whereas the other results were analyzed by ANOVA followed by the Tukey test, using SAS at 5% significance level (SAS Institute Inc., Cary, NC, USA). For IVM, the treatments F, B, O, and B + O did not affect (P > 0.05) nuclear maturation (73.92 to 78.78%) and cortical granule migration rates (58.89 to 66.76%). Regarding pronuclear development, the treatment FO (76.67%) was similar (P > 0.05) to the control group (82.95%), which was superior (P < 0.05) to the treatments BB (56.98%), BO (39.02%), OB (37.36%), and OO (39.24%). Blastocyst rates in FBF (42.8%) and control (45.0%) groups were superior (P < 0.05) to treatment OOO (26.0%) but similar (P > 0.05) to FOF, BBB, BOB, and OBO (32.0 to 35.8%). The average of blastocyst ICM cells of the group OOO (16.79) was inferior (P < 0.05) to the other groups. However, the average of TF cells on blastocysts of the group OOO (38.25) was similar (P > 0.05) to the groups BBB (45.74) and BOB (45.60) and inferior (P < 0.05) to the groups CONT (57.59), FBF (54.41), FOF (56.74), and OBO (47.35). The total average cells in the blastocysts of the group OOO (56.04) was inferior (P < 0.05) to the groups CONT (84.86), FBF (78.96), FOF (81.32), BBB (68.11), BOB (69.55), and OBO (69.82). The total cell number in the treatments, with several sources of protein supplementation, varied from 56.04 to 84.86. Considering the evaluation interval, this average cell number was discreetly inferior to that expected for the chronological age of the blastocysts. We concluded that it is possible to produce bovine embryos in the absence of F and/or B, with the protein source O, although it reduced blastocyst rates when used in all 3 steps of embryo in vitro production and resulted in blastocysts of inferior quality. Financial support: FAPESP 05/60389-2 and CNPq.


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