Developmental rate and allocation of transgenic cells in rabbit chimeric embryos

Zygote ◽  
2008 ◽  
Vol 16 (1) ◽  
pp. 87-91 ◽  
Author(s):  
P. Chrenek ◽  
A.V. Makarevich ◽  
M. Bauer ◽  
R. Jurcik
Keyword(s):  
Developmental Rate ◽  
Blastocyst Stage ◽  
Egfp Expression ◽  
Control Group ◽  
Cell Stage ◽  
Embryonic Shield ◽  
Developmental Capacity ◽  
Transgenic Cells ◽  
Average Total Number ◽  
Rabbit Embryos

SummaryThe objective of this study was to compare developmental capacity of rabbit chimeric embryos and the allocation of the EGFP gene expression to the embryoblast (ICM) or embryonic shield. We produced chimeric embryos (TR<>N) by synchronous transfer of two or three blastomeres at the 16-cell stage from transgenic (TR) into normal host embryos (N) at the same stage. In the control group, two to three non-transgenic blastomeres were used to produce chimeric embryos. The TR embryos were produced by microinjection of EGFP into both pronuclei of fertilized rabbit eggs. The developmental rate and allocation of EGFP-positive cells of the reconstructed chimeric embryos was controlled at blastocyst (96 h PC) and embryonic shield (day 6) stage.All chimeric embryos (120/120, 100%) developed up to blastocyst stage. Using fluorescent microscope, we detected green signal (EGFP expression). In 90 chimeric (TR<>N) embryos (75%). Average total number of cells in chimeric embryos at blastocyst stage was 175 ± 13.10, of which 58 ± 2.76 cells were found in the ICM area. The number of EGFP-positive cells in the ICM area was 24 ± 5.02 (35%). After the transfer of 50 chimeric rabbit embryos at the 16-cell stage, 20 embryos (40%) were flushed from five recipients on day 6 of pregnancy, of which five embryos (25%) were EGFP positive at the embryonic shield stage.Our results demonstrate that transgenic blastomeres in synchronous chimeric embryos reconstructed from TR embryos have an ability to develop and colonize ICM and embryonic shield area.

Antioxidant and developmental capacity of retinol on the in vitro culture of rabbit embryos

Zygote ◽  
2018 ◽  
Vol 26 (4) ◽  
pp. 326-332 ◽  
Author(s):  
Ahmed M. Elomda ◽  
Mohamed F. Saad ◽  
Ayman M. Saeed ◽  
Ashraf Elsayed ◽  
Ahmed O. Abass ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Blastocyst Stage ◽  
Control Group ◽  
Enzymatic Antioxidants ◽  
Vertebrate Development ◽  
Junction Protein ◽  
Total Antioxidant ◽  
Developmental Capacity ◽  
Rabbit Embryos

SummaryOxidative stress is a major cause of defective embryo development during in vitro culture. Retinoids are recognized as non-enzymatic antioxidants and may have an important role in the regulation of cell differentiation and vertebrate development. However, there are not enough reports discussing the antioxidant and developmental capacity of retinoids, including retinol (RT), on the in vitro development of embryos recovered from livestock animals, particularly in rabbit species. Therefore, morula embryos obtained from nulliparous Red Baladi rabbit does were cultured for 48 h in TCM199 medium in the absence of RT (control group) or in the presence of RT at concentrations of 10, 100 and 1000 nM. The developmental capacity to the hatched blastocyst stage, the antioxidant biomarker assay and the expression of several selected genes were analyzed in each RT group. The data show that RT significantly (P<0.001) promoted the embryo hatchability rate at the concentration of 1000 nM to 69.44% versus 29.71% for the control. The activity of malondialdehyde (MDA) level was significantly (P<0.05) lower in the RT groups than in the control group, while the total antioxidant capacity (TAC), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were significantly (P<0.05) higher following treatment with RT. Furthermore, RT treatment considerably upregulated the relative expression of gap junction protein alpha 1 (GJA1), POU class 5 homeobox 1 (POU5F1) and superoxide dismutase 1 (SOD1) genes compared with the control group. The current study highlights the potential effects of RT as antioxidant in the culture medium on the in vitro development of rabbit embryos.

scholarly journals Baicalin improves the in vitro developmental capacity of pig embryos by inhibiting apoptosis, regulating mitochondrial activity and activating sonic hedgehog signaling

2019 ◽  
Vol 25 (9) ◽  
pp. 538-549 ◽  
Author(s):  
Qing Guo ◽  
Mei-Fu Xuan ◽  
Zhao-Bo Luo ◽  
Jun-Xia Wang ◽  
Sheng-Zhong Han ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Signaling Pathway ◽  
Sonic Hedgehog ◽  
Hedgehog Signaling ◽  
Control Group ◽  
Mitochondrial Activity ◽  
Cell Stage ◽  
Shh Signaling ◽  
Developmental Capacity

Abstract Baicalin, a traditional Chinese medicinal monomer whose chemical structure is known, can be used to treat female infertility. However, the effect of baicalin on embryonic development is unknown. This study investigated the effects of baicalin on in vitro development of parthenogenetically activated (PA) and in vitro fertilized (IVF) pig embryos and the underlying mechanisms involved. Treatment with 0.1 μg/ml baicalin significantly improved (P < 0.05) the in vitro developmental capacity of PA pig embryos by reducing the reactive oxygen species (ROS) levels and apoptosis and increasing the mitochondrial membrane potential (ΔΨm) and ATP level. mRNA and protein expression of sonic hedgehog (SHH) and GLI1, which are related to the SHH signaling pathway, in PA pig embryos at the 2-cell stage, were significantly higher in the baicalin-treated group than in the control group. To confirm that the SHH signaling pathway is involved in the mechanism by which baicalin improves embryonic development, we treated embryos with baicalin in the absence or presence of cyclopamine (Cy), an inhibitor of this pathway. Cy abolished the effects of baicalin on in vitro embryonic development. In conclusion, baicalin improves the in vitro developmental capacity of PA and IVF pig embryos by inhibiting ROS production and apoptosis, regulating mitochondrial activity and activating SHH signaling.

Morphokinetics and in vitro developmental potential of monopronucleated ICSI zygotes until the blastocyst stage

Zygote ◽  
2020 ◽  
Vol 28 (3) ◽  
pp. 217-222
Author(s):  
Silvia Mateo ◽  
Francesca Vidal ◽  
Beatriz Carrasco ◽  
Ignacio Rodríguez ◽  
Buenaventura Coroleu ◽  
...  
Keyword(s):  
Blastocyst Stage ◽  
Control Group ◽  
Study Group ◽  
Comprehensive Understanding ◽  
Developmental Potential ◽  
Morphokinetic Parameters ◽  
Developmental Capacity ◽  
Blastocyst Rate ◽  
Kinetics Of

SummaryThe aim of this study was to provide a more comprehensive understanding of 1PN intracytoplasmic sperm injection (ICSI) zygotes. To achieve this objective, we assessed whether all 1PN-derived embryos showed a similar morphokinetic pattern, and if the morphokinetic behaviour of 1PN-derived embryos was comparable with that of 2PN-derived embryos. In total, 149 1PN ICSI zygotes (study group) and 195 2PN ICSI zygotes (control group) were included in the study. Embryo development potential was evaluated in terms of blastocyst rate. Morphokinetic parameters, including the pronucleus diameter and kinetics of in vitro development, were also analyzed. Embryos derived from 1PN ICSI zygotes showed impaired development compared with 2PN-derived embryos, with blastocyst rates of 28.9% and 67.2%, respectively. The diameter of the pronucleus of 1PN zygotes was larger than that of 2PN zygotes. When compared with 2PN-derived embryos, those derived from 1PN zygotes had a visible pronucleus for a shorter time, in addition to a longer syngamy time and slower kinetic behaviour from two to nine cells. When 1PN-derived blastocysts and 2PN-derived blastocysts were compared, the developmental kinetics were similar in both groups, except for a delayed and longer duration of the compaction phase in 1PN-derived embryos. In conclusion, monopronucleated ICSI zygotes present differences in developmental capacity and morphokinetic behaviour compared with 2PN ICSI zygotes, showing particular morphokinetic parameters related to pronucleus formation. Only the 1PN ICSI-derived embryos that reached the blastocyst stage have similar morphokinetic development to blastocysts from 2PN zygotes.

131 DYNAMICS OF HISTONE H3 METHYLATION AT POSITIONS K4 AND K9 IN MOUSE, RABBIT, AND BOVINE PRE-IMPLANTATION EMBRYOS

2006 ◽  
Vol 18 (2) ◽  
pp. 174 ◽  
Author(s):  
K. Lepikhov ◽  
F. Yang ◽  
C. Wrenzycki ◽  
V. Zakhartchenko ◽  
H. Niemann ◽  
...  
Keyword(s):  
Histone H3 ◽  
Distribution Patterns ◽  
Blastocyst Stage ◽  
Dna Demethylation ◽  
Preimplantation Embryos ◽  
Staining Procedure ◽  
Cell Stage ◽  
Paternal Genome ◽  
Histone H3 Methylation ◽  
Rabbit Embryos

In mammals, upon the penetration of sperm into the oocyte, the paternal genome undergoes dramatic epigenetic changes. Protamin packaging of DNA is replaced by histones that acquire specific modifications. In mouse zygotes, paternal DNA gets rapidly demethylated by an active mechanism. In bovine zygotes the methylation from paternal DNA is erased only partially, and in rabbit zygotes it persists at the initial level. To understand whether these reprogramming differences are also reflected in histone modifications, we examined the dynamic changes of histone H3 methylation at positions K4 and K9 in mouse, bovine, and rabbit zygotes and in preimplantation embryos using an immunofluorescence staining procedure (Lepikhov and Walter 2004 BMC Dev. Biol. 4, 12). In zygotes, maternal chromatin contains both types of histone H3 methylation. After fertilization protamines in sperm are very quickly replaced by histones. After the formation of nucleosomes, histone H3 acquires methylation at position K4 in a stepwise manner: first as mono-methylated form and later as tri-methylated. In the late zygote, both paternal and maternal pronuclei show equal levels of histone H3 methylation at position K4. Regardless of the differences in DNA reprogramming in these 3 species, H3/K9 di-methylation is not detected on paternal genomes and is only associated with maternal genomes. During the subsequent cleavage stages, H3/K9 di-methylation decreases gradually and becomes hardly detectable in 4-cell bovine and rabbit embryos. In mouse embryos, it is detectable through all the stages. Bovine embryos reacquire this type of modification at the 8-16 cell stage, and it remains at the very low levels in rabbit, embryos until the blastocyst stage. In conclusion, mouse, rabbit and bovine zygotes show similar patterns of H3/K4triMe and H3/K9diMe distribution despite the difference in paternal DNA demethylation. The dynamics of H3/K9diMe distribution patterns in cleavage stage embryos from all embryos do not correlate with embryonic genomic activation events.

194 EXPRESSION OF microRNA-15a, 16, AND 21 AND THEIR POSSIBLE ROLES IN MOUSE EMBRYOS DEVELOPING IN VITRO

2008 ◽  
Vol 20 (1) ◽  
pp. 176
Author(s):  
D. X. Zhang ◽  
X. H. Shen ◽  
X. S. Cui ◽  
N.-H. Kim
Keyword(s):  
Gene Expression ◽  
Copy Number ◽  
Blastocyst Stage ◽  
Early Embryogenesis ◽  
Preimplantation Embryos ◽  
Control Group ◽  
Cell Stage ◽  
Expression Levels ◽  
Apoptotic Gene

MicroRNAs (miRNAs) are small (~22 nucleotides) non-coding RNA molecules that can regulate gene expression by base-pairing with fully or partially sequence-complementary target mRNAs. Hundreds of miRNAs have been identified in various multicellular organisms and many miRNAs are evolutionarily conserved. While miRNAs play an important role in animal development, little is known about their biological function during early mammalian development. In order to obtain insight into the role of miRNAs in early embryogenesis, we first determined the expression levels of three apoptosis-related miRNAs, miR-15a, -16, and -21 in mouse preimplantation embryos using TaqMan� MicroRNA Assays. Five embryos of each developmental stage were snap-frozen and amplified by stem-loop RT primer and TaqMan Universal PCR Master Mix (Applied Biosystems Inc., Foster City, CA, USA). The miRNA concentrations (10–X) in embryo samples were calculated by standard curve from synthetic lin-4 miRNA and the absolute copy number per embryo was obtained based on the formula of 6.02 � 10(8–X). All three miRNAs had low expression levels from the zygote to the 8-cell stage and were up-regulated thereafter. In general, among the three miRNAs, miR-15a exhibited the lowest expression in preimplantation embryos, while miR-16 exhibited the highest. Because of the low levels of miRNA-15a, we determined developmental ability and apoptosis of embryos following microinjection of miRNA-15a. The microinjection of miR-15a into zygotes did not affect embryo development up to the blastocyst stage (miR-15a, 90 � 4.5% v. buffer 94.6 � 5.8%); however, it did induce a significant degree of apoptosis (P < 0.05; Tukey's multiple range test). Furthermore, the expression levels of miR-15a and -16 were increased in microinjected blastocysts compared to the control group (copy number per blastocyst, miR-15a, 6991 � 1223 v. 3098 � 592; miR-16, 196216 � 958 v. 133514 � 6059). Real-time RT-PCR data showed that the gene expression levels of the housekeeping gene GAPDH, the anti-apoptotic gene Bcl-xL, and the miRNA pathway-related genes GW182 and Dicer remained unchanged in miR-15a-injected blastocysts compared to the control group. In contrast, the expression of the stem cell-specific transcriptional factor Oct-4 (fold change, 1.451 � 0.12), the pro-apoptotic gene Bax (1.418 � 0.12), and Caspase 3 (1.314 � 0.19) were significantly increased in microinjected blastocysts. In addition, treatment of 2-cell embryos with 600 µm H2O2 induced apoptosis and increased the expression level of miR-16 at the blastocyst stage (P < 0.05). Taken together, the changes in the expression levels of miR-15a, -16, and -21 in various embryonic developmental stages indicate a possible role for them in early embryogenesis. Furthermore, the high expression levels of miR-15a and miR-16 seem to be linked to apoptosis in blastocyst-stage embryos; this may be due to an increase in the expression of pro-apoptotic genes.

Open-pulled straw (OPS) vitrification of in vitro fertilised mouse embryos at various stages

2008 ◽  
Vol 56 (2) ◽  
pp. 245-253 ◽  
Author(s):  
Chang-Liang Yan ◽  
Qi-En Yang ◽  
Guang-Bin Zhou ◽  
Yun-Peng Hou ◽  
Xue-Ming Zhao ◽  
...  
Keyword(s):  
Survival Rate ◽  
Developmental Stages ◽  
Developmental Rate ◽  
Blastocyst Stage ◽  
Significant Loss ◽  
Mouse Embryos ◽  
Cell Stage ◽  
Fresh Embryos

The present study was designed to investigate the cryotolerance of in vitro fertilised (IVF) mouse embryos at various preimplantation developmental stages. IVF mouse embryos were vitrified by the open-pulled straw (OPS) method. After warming, embryos were morphologically evaluated and assessed by their development to blastocysts, hatched blastocysts or term. The results showed that a high proportion (93.3–100.0%) of vitrified embryos at all developmental stages were morphologically normal after recovery. The developmental rate of vitrified 1-cell embryos to blastocyst (40.0%) or hatched blastocyst (32.7%) or term (9.3%) was significantly lower than that from other stages (P < 0.05). Vitrified embryos from 2-cell to early blastocyst stage showed similar blastocyst (71.8–89.5%) and hatched blastocyst rates (61.1–69.6%) and could develop to term without a significant loss of survival compared with those of fresh embryos (P > 0.05). Vitrified 2-cell embryos showed the highest survival rate in vivo (50.6%, 88/174), compared with that from other stages (9.3–30.5%, P < 0.05). The data demonstrate that the OPS method is suitable for the cryopreservation of IVF mouse embryos from 2-cell stage to early blastocyst stage without a significant loss of survival. Embryos at the 2-cell stage had the best tolerance for cryopreservation in the present study.

Production of rabbit chimeric embryos by aggregation of zona-free nuclear transfer blastomeres

Zygote ◽  
2005 ◽  
Vol 13 (1) ◽  
pp. 39-44 ◽  
Author(s):  
P. Chrenek ◽  
A.V. Makarevich
Keyword(s):  
Nuclear Transfer ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Control Group ◽  
Embryonic Cells ◽  
Cell Stage ◽  
Egfp Gene ◽  
Chimeric Blastocysts ◽  
Rabbit Embryos

The objective of this study was to compare in vitro developmental capacity of zona-free aggregated rabbit chimeric embryos and the allocation of EGFP (enhanced green fluorescence protein) gene expression to the inner cell mass (ICM). We produced chimeric embryos by synchronous aggregation of zona-free blastomeres from embryonic cell nuclear transfer (EMB-NT) or somatic cell nuclear transfer (SC-NT) and blastomeres from normal zona-free embryos (N) at the 16-cell stage. In the control group, transgenic (TR) and normal zona-free embryos were used to produce chimeric embryos (TR<>N). EMB-NT embryos were produced by fusion of enucleated oocytes with embryonic cells, which were derived from 32-cell stage transgenic embryos bearing the EGFP gene. The SC-NT embryos were produced by fusing enucleated oocytes with cumulus cells, which were derived from homozygotes transgenic for the EGFP gene female oocytes at 16 h post-coitum. Nuclei of transgenic blastomeres emitted a green signal under fluorescence microscopy. Zona-free EMB-NT or zona-free SC-NT rabbit embryos, both with EGFP fluorescence, as well as TR and zona-free rabbit embryos with no fluorescence (EMB-NT<>N, SC-NT<>N, TR<>N) were aggregated on day 2.5 and evaluated on day 5. The proportion of EMB-NT<>N embryos that developed to the blastocyst stage was significantly higher compared with SC-NT derived cells (p<0.05), but significantly lower than in TR<>N chimeric blastocysts (p<0.001). Similarly, a higher proportion (p<0.001) of EGFP-positive cells allocated to ICM of chimeric blastocysts was revealed in TR<>N chimeras (55%), compared with EMB-NT<>N (35%) and SC-NT<>N (21%). Our results indicate that synchronous chimeric embryos reconstructed from TR embryos were better able to develop and colonize the ICM area than EMB-NT and SC-NT embryos. In this study we have demonstrated for the first time that rabbit NT-derived embryos are able to develop into chimeric blastocysts and participate in the ICM area.

Mouse oocytes nucleoli rescue embryonic development of porcine enucleolated oocytes

Zygote ◽  
2017 ◽  
Vol 25 (6) ◽  
pp. 675-685 ◽  
Author(s):  
Martin Morovic ◽  
Frantisek Strejcek ◽  
Shoma Nakagawa ◽  
Rahul S. Deshmukh ◽  
Matej Murin ◽  
...  
Keyword(s):  
Embryonic Development ◽  
De Novo ◽  
Blastocyst Stage ◽  
Rrna Synthesis ◽  
Control Group ◽  
Cell Stage ◽  
Nucleolar Proteins ◽  
Transmission Electron ◽  
Binding Factor ◽  
Upstream Binding Factor

SummaryIt is well known that nucleoli of fully grown mammalian oocytes are indispensable for embryonic development. Therefore, the embryos originated from previously enucleolated (ENL) oocytes undergo only one or two cleavages and then their development ceases. In our study the interspecies (mouse/pig) nucleolus transferred embryos (NuTE) were produced and their embryonic development was analyzed by autoradiography, transmission electron microscopy (TEM) and immunofluorescence (C23 and upstream binding factor (UBF)). Our results show that the re-injection of isolated oocyte nucleoli, either from the pig (P + P) or mouse (P + M), into previously enucleolated and subsequently matured porcine oocytes rescues their development after parthenogenetic activation and some of these develop up to the blastocyst stage (P + P, 11.8%; P + M, 13.5%). In nucleolus re-injected 8-cell and blastocyst stage embryos the number of nucleoli labeled with C23 in P + P and P + M groups was lower than in control (non-manipulated) group. UBF was localized in small foci within the nucleoli of blastocysts in control and P + P embryos, however, in P + M embryos the labeling was evenly distributed in the nucleoplasm. The TEM and autoradiographic evaluations showed the formation of functional nucleoli and de novo rRNA synthesis at the 8-cell stage in both, control and P + P group. In the P + M group the formation of comparable nucleoli was delayed. In conclusion, our results indicate that the mouse nucleolus can rescue embryonic development of enucleolated porcine oocytes, but the localization of selected nucleolar proteins, the timing of transcription activation and the formation of the functional nucleoli in NuTE compared with control group show evident aberrations.

103 BIRTH OF CLONED PIGLETS DERIVED FROM AN OPTIMIZED IN VITRO BLASTOCYST PRODUCTION SYSTEM BY TRICHOSTATIN A TREATMENT

2007 ◽  
Vol 19 (1) ◽  
pp. 168
Author(s):  
Y.-H. Zhang ◽  
Y.-T. Du ◽  
K. Zhang ◽  
J. Li ◽  
P. M. Kragh ◽  
...  
Keyword(s):  
Culture Media ◽  
Trichostatin A ◽  
Blastocyst Stage ◽  
Control Group ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Deacetylase Inhibitor ◽  
The One ◽  
Effective Group

The present study was designed to examine the effect of trichostatin A (TSA, a histone deacetylase inhibitor) treatment on in vitro developmental ability of pig cloned embryos and to evaluate the feasibility of producing piglets from these embryos. Cell lines were established from 40-day-old fetuses, and adult ear skin was used as nuclear donor. In vitro-matured oocytes from abattoir-derived sow ovaries were used as cytoplast recipients for micromanipulator-assisted somatic cell nuclear transfer (SCNT). Data were analyzed by using SPSS (11.0) with one-way ANOVA, and each experiment was replicated at least 3 times. In Experiment 1, immediately after simultaneous fusion and activation, the reconstructed couplets were randomly cultured in porcine zygote medium 3 (PZM3; Yoshioka et al. 2002 Biol. Reprod. 66, 112–119) with 10 �g mL-1 cytochalasin B (CB), 10 �g mL-1 cycloheximide (CHX), and 0 nM, 5 nM, or 50 nM TSA for the first 4 h. Cloned embryos (fused reconstructed couplets) were moved to the same culture media but without CB and CHX and further cultured at 38.5�C, under 5% CO2, 5% O2, 90% N2 and 100% humidity. After incubation for a total of 8–14 h in 50 nM, 19–24 h in 50 nM or 5 nM, and 31–36 h in 50 nM TSA in PZM3 (0 nM TSA serves as control for each group), the embryos were further cultured in vitro without TSA in PZM3 for up to 168 h. Cleavage and blastocyst development rates, based on embryos cultured, were recorded at 48 and 168 h of IVC, respectively. Results showed that 50 nM TSA treatment for 19-24 h supported a higher blastocyst development rate than the control group [No. blastocysts/No. embryos cultured (mean � SEM): 107/258, 47.4 � 5.9% vs. 65/324, 20.0 � 2.3%, respectively; P &lt; 0.05], whereas similar pre-implantation development was obtained between the other 3 test groups and the control. In Experiment 2, TSA-treated cloned embryos at the one-cell stage or blastocyst stage were transferred to recipients to examine the possibility of producing piglets. Ten cloned piglets (2 are healthy and 8 died shortly after birth) and one ongoing pregnancy were obtained from 3 recipients who received an average of 110 one-cell stage embryos, whereas 4 piglets originating from traditional cloning were produced from one recipient which received 28 traditional cloned blastocysts (produced from the effective group in Experiment 1) and 30 handmade but non-TSA-treated ones. Our data demonstrate that TSA treatment after SCNT in porcine can significantly improve the in vitro blastocyst production, and embryos treated with TSA could support full-term development and result in healthy offspring.

45 EFFECT OF OSMOLARITY IN CULTURE MEDIUM ON THE PRE-IMPLANTATION DEVELOPMENT OF PORCINE NT AND IVF EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 141
Author(s):  
I. S. Hwang ◽  
H. J. Moon ◽  
J. H. Shim ◽  
M. R. Park ◽  
D. H. Kim ◽  
...  
Keyword(s):  
Culture Medium ◽  
Developmental Rate ◽  
Blastocyst Stage ◽  
Early Embryo ◽  
Final Concentration ◽  
Control Group ◽  
In Vitro Production ◽  
Fetal Fibroblasts ◽  
Vitro Production

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.

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