• Development and Reproduction
• /
• v.12 no.1
• /
• pp.19-30
• /
• 2008

Proper development of fertilized oocyte to blastocyst is a key step in mammalian development to implantation. During development of preimplantation embryos, the mammalian embryo needs supply the energy substrate for keep viability. Usually mammalian oocyte get substrate especially energy substrate from oviduct and uterus, because it does not store much substrate into cytoplasm during oogenesis. Carbohydrates are known as a main energy substrate for preimplantation stage embryos. Glucose, lactate and pyruvate are essential component in preimplantation embryo culture media and there are stage specific preferences to them. Glucose transporter and $H^+$-monocarboxylate cotransporter are a main mediator for carbohydrate transport and those expression levels are primarily under the control of intrinsic or extrinsic factors like insulin and glucose. Other organic substances, amino acids, lipids and nucleotides are used as energy substance and cellular regulation factor. Though since 1960s, successful development of fertilized embryo to blastocyst has been accomplished with chemically defined medium for example BWW and give rise to normal offspring in mammals, the role of metabolites and the regulation of intermediary metabolism are still poorly understood. Glucose may permit expression of metabolic enzymes and transporters in compacting morula, capable of generating the energy required for blastocyst formation. In addition, it has been suggested that the cytokines can modulate the metabolic rate of carbohydrate in embryos and regulate the preimplantation embryonic development through control the metabolic rate. Recently we showed that lactate can be used as a mediator for preimplantation embryonic development. Those observations indicate that metabolites of carbohydrate are required by the early embryo, not only as an energy source, but also as a key substrate for other regulatory and biosynthetic pathways. In addition metabolites of carbohydrate may involve in cellular activity during development of preimplantation embryos. It is suggested that through these regulation and with other regulation mechanisms, embryo and uterus can prepare the embryo implantation and further development, properly.

• Journal of Environmental Health Sciences
• /
• v.24 no.2
• /
• pp.126-133
• /
• 1998

Effects of B(a)P on preimplantation mouse embryos in vitro were studied. Preimplantation mouse embryos were exposed to a concentration of 0.3, 1, 3 and 10 $\mu$M B(a)P for 72 hrs. The toxicological effects of B(a)P were evaluated by morphological observation of embryos up to the blastocyst stage, and by measuring DNA, RNA and protein synthesis by radioactive precursor incorporation. At 1 $\mu$M B(a)P did not affect preimplantation development but interfered with hatching and ICM formation. Suppressing effect of ICM formation was dose dependent. At the eight cell stage, the developmental rate was decreased at above 3 $\mu$M of B(a)P. At the blastocyst stage, attachment and trophoblast outgrowth were diminished at the 10 $\mu$M of B(a)P and ICM formation was decreased at 1 $\mu$M of B(a)P. Inner cell number of blastocyst was decreased dose dependently. So, number of ICM was one of the most sensitive and toxicological end point. The RNA incorporation rate of 0.1 $\mu ^3$H-uridine was dosedependent and the protein incroporation of 0.5 $\mu Ci ^{35}$S-methionine showed a significant decrease after 48 hrs. But the DNA incorporation rate of methyl-$^3$H thymidine was not affected. Our results suggested that B(a)P did not affect the DNA replication but transcription was inhibited by dose dependent manner. There delay of development during the blastocyst stage was mainly due to the inhibition of RNA synthesis followed by protein synthesis.

• Proceedings of the KSAR Conference
• /
• 2004.06a
• /
• pp.235-235
• /
• 2004

Although studies for important genes concerned in preimplantation stage that encompasses the period from fertilization to implantation were reported for mice and cows, little information relevant to this subject is known in pigs. (omitted)

• Clinical and Experimental Reproductive Medicine
• /
• v.27 no.4
• /
• pp.381-385
• /
• 2000

Objective: To verify the effect of two forms (growth factor and growthfactor-reduced) of solubilized Matrigel on the development in mouse preimplantation embryos. Methods: Late 2-cell stage eggs were cultured through the blastocyst stage in the presence of GF- or GFR-Matrigel (0.5%, v/v). Morphological development, cell number and % apoptotic nuclei of blastocyst were measured by Roecst staining and TUNEL of nuclei. Results: Morphological development, number of cells per embryo was significantly increased in the presence of GF- or GFR-Matrigel. Culture of the embryos in the GF-Matrigel gave the best result. Conclusion: Low concentration of solubilized Matrigel improved development of mouse embryos regardless of growth factor content of the Matrigel. Growth factors and extracellular matrix protein included in the Matrigel synergistically potentiated the development of mouse embryos.

• Journal of Embryo Transfer
• /
• v.25 no.3
• /
• pp.179-187
• /
• 2010

Embryonic compaction is essential for normal preimplantation development in mammals. The present study was to investigate the effects of compaction patterns on developmental competence of pig embryos. The proportion of blastocyst formation derived from compacted morula was higher than those of compacting and pre-compacting morula (P<0.01). Nuclei numbers of inner cell mass (ICM), trophectoderm (TE), and total of blastocysts derived from compacted group were also superior to those of compacting and pre-compacting groups (P<0.05). Then, compaction patterns, developmental ability and structural integrity were compared between mono- and poly-spermic embryos. The rate of compacted morula in mono-spermic embryos was higher than that of poly-spermic embryos (P<0.05). Especially, the rate of blastocyst formation derived from compacted embryos in mono-spermic embryo group was higher than that of poly-spermic embryo group (P<0.05), although no difference was detected between the two groups in the structural integrity. Finally, we confirmed that beta-catenin was differentially expressed according to compaction patterns in morula and blastocyst stage embryos. In conclusion, our results suggest that the compaction patterns during preimplantation development play a direct role in developmetal competence and quality of pig embryos.

• Proceedings of the Korean Society of Developmental Biology Conference
• /
• 1998.07a
• /
• pp.12-18
• /
• 1998

Tremendous progress has been made over the past quarter-century studying the genetics of gametogenesis and the resulting gametes and embryos. Studies merging molecular techniques and conventional cytogenetics are now beginning to bridge the gap between what we have learned about the meiotic process in males and females and what we know of the mitotic chromosomes of zygotes. Numerical abnormalities in sperm, oocytes and embryo can now diagnosed by fluorescence in situ hybridization (FISH). "At risk" couples can, therefore, have only unaffected embryos replaced in the sterus and avoid the possibility of terminating a pregnancy that might only be diagnosed as affected later gestation. Single-cell genetic analysis has also provided powerful tools for studying genetic defects arising during early human development. Recent studies of sperms, oocytes and cleavage-stage human embryos have revealed an unexpectedly high incidence. These genetic abnormalities are likely to contribute to early pregnancy loss and have important implications for improving pregnancy rates in infertile couples by assisted reproduction. The widespread use of preimplantation genetic diagnosis (PGD) awaits further documentatio of safety and accuracy. Other issues also must be addressed. First, the ethical issues regarding germ cell and embryo screening must be addressed including what diseases are serious enough to warrant the procedure. Another concern is the use of this technology for non-genetic disorders such as gender selection. Finally, the experimental nature of these procedure must continually be discussed with patients, and long-term follow-up studies must be undertaken. Development of more accurate and less expensive assays coupled with improved assisted reproductive technology success rates may make PGD a more widely use clinical tool. The future awaits these development.velopment.

• Proceedings of the KSAR Conference
• /
• 2003.06a
• /
• pp.69-69
• /
• 2003

Although effect of TGF$\beta$$_1$ on preimplantation embryo development was reported at mice, little information relevant to this subject is known in bovine. The objectives of this study were to investigate TGF$\beta$$_1$, and TGF$\beta$$_1$ receptors type I and II expression, known as important factors in the embryo development, at unfertilized oocytes and fertilized embryos that will be used as basic data to be compared to NT embryos. We postulated that TGF$\beta$$_1$ may have a beneficial effect on the preimplantation embryo and show different expression patterns as embryo stages change. We have used immunocytochemistry to investigate the presence in unfertilized oocytes and preimplantation embryos of TGF$\beta$$_1$ and the essential components of the TGF$\beta$$_1$ signalling pathway, TGF$\beta$$_1$ receptors type I and II. We found that both receptors, as well as TGF$\beta$$_1$, were present in the unfertilized oocytes. This indicates that TGF$\beta$$_1$, is a maternally expressed protein. At the morulae and blastocyst stages the TGF$\beta$$_1$ receptor type II was not present, but the TGF$\beta$$_1$ receptor type I was present at both stages and we can confirm the TGF$\beta$$_1$ expression of high level at 8-cell stage. These findings support our hypothesis that the TGF$\beta$$_1$, and TGF$\beta$$_1$ receptors may interact with the oocyte and preimplantation embryo, and that TGF$\beta$$_1$ signalling may be important for the development of the oocyte and the preimplahtation embryo.

• Development and Reproduction
• /
• v.2 no.1
• /
• pp.9-20
• /
• 1998

It has been wel known that phospholipase C(PLC) plays an important role in the intracellular signaling in a variety of cell types. However, involvement of PLC in mouse oocyte maturation and preimplantation embryo development remains unknown. The present study examined the expression patterns of the mouse PLC \beta 1 and \gamma 1 during oocyte maturatio and preimplantation embryo development study examined the expression patterns of the mouse PLC \beta 1 and \gamma 1 during oocyte maturation and preimplantation embryo development by the competitive reverse transcription-polymerase chain reaction (RT-PCR method). PLC \gamma 1 mRNA (0.1 fg) was readily detected in germinal vesicle (GV)-stage oocyte and its level was reduced as meiotic resumption proceeded. PLC-\beta 1 mRNA (<0.1 fg) as detected at low level at GV-stage oocytes and scarcely detected at germinal vescle breakdown (GVBD)-stage oocytes. After fertilization, both PLC \beta 1 and \gamma 1 mRNA levels began to increase at morula-stage embryos (0.2 fg) and were more prominent in blastocyst-stage embryos(1 fg). to elucidate the possible involvement of PLC via protein kinase C(PKC) pathway during oocyte maturation and preimplantation embryo development , the effects of sphingosine (PKC inhibitor), sn-$diC_{8}$(PKC activator) anc U73122 (PLC ingibitor) were examined. Treatment of GV-stage oocytes with sphingosine (20 \mu M) facilitated the meiotic resuption by 10-20 over the control within 1 h as judged by GVBD, whereas U73122 failed to show any significant effect. U73122 (10 \mu M) effectively blocked the compaction of morula, while sn-$diC_{8}$(50 \mu M). In summary, the present study shows that the mouse PLC \beta 1 and \gamma 1 are expressed in a developmental stage-specific manner and PLC-PKC pathway may be involved in early preimplantation embryo development.

• Journal of Embryo Transfer
• /
• v.6 no.1
• /
• pp.33-40
• /
• 1991

In vitro developmental ability of early preimplantation monse embryos was shown to be depend on the embryonic stages, media and snpplements and their interaction(Experiment 1). The development of I-cell embryos were more promoted in the complex medinm(Ham's Fl0) than in the simple one(m-KRB), but that of 2-cell embryos showed the reverse effect. The bovine serum albumin(BSA) as a medium snpplement more promoted the development of I- and 2-cell embryos, compared with human fetal cord serum(HCS). On the other hand, the harmful effect of HCS was especially shown on the early cleavage in the embryonic development of the two stages. The effect of serum, in the respect of interaction between media and snpplements. was also more significantly appeared in m-KRB than Ham's Fl0. In the experiment 2, when the harmful effect of HCS was compared with that of fetal bovine serum(FBS), the former more promoted the development of l - and 2-cell embryos than the latter. The effect of HCS was more significantly shown in the development of I-cell than that of 2-cell embryos. Conclusively, as I- and 2-cell embryos were different in the requirements for the in vitro development. the optimal medium and supplement have to be selected for each embryonic stage. It is also respected to the better result if it take into consideration into the kinds of sera when serum is used for culture of early preimplantation embryos.

• Journal of Embryo Transfer
• /
• v.25 no.2
• /
• pp.103-110
• /
• 2010

The first morphogenetic event of preimplantation development, compaction, was required efficient production of porcine embryos in vitro. Compaction of the porcine embryo, which takes place at post 4-cell stage, is dependent upon the adhesion molecule E-cadherin. The E-cadherin through ${\beta}$-catenin contributes to stable cell-cell adhesion. Rho-associated kinase (ROCK) signaling was found to support the integrity of E-cadherin based cell contacts. In this study, we traced the effects of ROCK-1 on early embryonic development and structural integrity of blastocysts in pigs. Then, in order to gain new insights into the process of compaction, we also examined whether ROCK-1 signaling is involved in the regulation of the compaction mediated by E-cadherin of cellular adhesion molecules. As a result, real-time RT-PCR analysis showed that the expression of ROCK-1 mRNA was presented throughout porcine preimplantation stages, but not expressed as consistent levels. Thus, we investigated the blastocyst formation of porcine embryos treated with LPA and Y27632. Blastocysts formation and their qualities in LPA treated group increased significantly compared to those in the Y27632-treated group (p < 0.05). Then, to determine whether ROCK-1 associates embryonic compaction, we explored the effect of activator and/or inhibitor of ROCK-1 on compaction of embryos in pigs. The rate of compacted morula in LPA treated group was increased compared to that in the Y27632-treated group (39.7 vs 12.0%). Furthermore, we investigated the localization and expression pattern of E-cadherin at 4-cell stage porcine embryos in both LPA- and Y27632-treated groups by immunocytochemical analysis and Western blot analysis. The expression of E-cadherin was increased in LPA-treated group compared to that in the Y27632-treated group. The localization of E-cadherin in LPA-treated group was enriched in part of blastomere contacts compared to that Y27632-treated group. ROCK-1 as a crucial mediator of embryo compaction may plays an important role in regulating compaction through E-cadherin of the cell adhesion during the porcine preimplantation embryo. We concluded that ROCK-1 gene may affect the developmental potential of porcine blastocysts through regulating embryonic compaction.