• Environmental Analysis Health and Toxicology
• /
• v.25 no.3
• /
• pp.241-251
• /
• 2010

Crucian carp (Carassius auratus) has been used as the sentinel species for POPs (Persistent Organic Pollutants) monitoring in aquatic environment. However, there is little information for dioxin toxicity and especially, early life stage toxicity in crucian carp have been never carried out. In this study, we investigated several toxic effects for 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) in fertilized egg obtained by natural fertilization from crucian carp. The embryos at 3 h post-fertilization (hpf) were treated with 0.039, 0.156, 0.625, and 2.5 (${\mu}g/L$) TCDD by waterborne exposure for 60 minutes and changed with fresh water 2 times per day. Fertilized eggs started hatching at 51 hpf and TCDD exposed embryo showed decrease of hatching rate in a dose-dependent manner at 75 hpf. Pericardial edema was continuously observed in larvae exposed to TCDD from hatching start time (51 hpf), followed by the onset of mortality. In addition, AhR-related gene, CYP1A was clearly increased by TCDD in a dose dependent manner. These results indicated that fertilized eggs obtained from crucian carp have the TCDD related gene regulation and a distinct TCDD developmental toxicity syndrome by TCDD exposure. Therefore, we suggested that early life stage test in crucian carp could be used as test methods on dioxins toxicity.

• Proceedings of the Korean Society of Developmental Biology Conference
• /
• 2003.10a
• /
• pp.108-108
• /
• 2003

The purpose of this is to investigate the effects of vitrification in open pulled straws (OPS) on in vitro survival of porcine embryos. Blastocysts were produced by in vitro fertilization of slaughterhouse-derived, in vitro matured oocytes with frozen-thawed boar semen, and subsequent culture on granulosa cell monolayer. After frozen-thawing, embryos were culture in NCSU-23 medium with 5 mM hypotaurine, 4 mg/$m\ell$ BSA and 10 ng/$m\ell$ for 48 hrs to survival tests. When blastocysts were frozen-thawed by OPS methods, the embryos with normal morphology were 32.1, 34.5 and 38.9 % in early blastocyst, blastocyst and expanded blastocyat stages. The rates of partial damaged embryos were significantly (P<0.05) higher in early biastocysts than expanded blastocysts. In another experiment, the embryos frozen by OPS methods were cultured for 48 hrs for survival and developmental rates in vitro. The proportions of embryos hatched were 11.8, 20.2 and 33.3% in embryos frozen-thawed at stages of early blastocyst, blastocyst and expanded embryos. On the other hand, The proportions of embryo with normal morphology after culture were 23.5, 25.0 and 33.3% in embryos frozen-thawed at stages of early blastocyst, blastocyst and expanded embryos. These finding indicate the possible broader application for OPS methods that this procedure described is relatively harmless, that it can be used for blastocysts of different developmental stages.

• Archives of Pharmacal Research
• /
• v.12 no.4
• /
• pp.269-275
• /
• 1989

Early embryo development and implantation were arrested in ICR mice which were passively immunized with a mouse monoclonal progesterone amtibody given as a single intraperitoneal injection at 12 hrs or 60 hrs post coitum (p. c.). Unimplanted embryos were recovered from the reproductive tract of the antibody-treated mice and none of these progressed to the blastocyst stage. The most pronounced effect was an arrest of embryonic development at a stage prior to cavitation. The plasma progesterone concentration in the blood taken by carbiac puncture increased greatly after the treatment by virtue of high affinity binding by the antibody in circulation. The result showed that passive immunization against progesterone shortly after mating interfered with early hormone dependent steps which were essential for normal embryonic development.

• Clinical and Experimental Reproductive Medicine
• /
• v.18 no.1
• /
• pp.41-48
• /
• 1991

The present investigation has been undertaken to elucidate the functional role of ovarian steroids on the mechanism of oviduct differentiation during early embryonic development in rat. The activity of alkaline phosphatase (ALPase) was measured in the oviduct tissue under different steroids treatment regime on day 9 pregnancy. The ALPase activity of the oviduct of pseudopregnant rat was compared with that of normal pregnant rat. The results of day 9 pregnancy rat oviduct clearly demonstrated that $17{\beta}-estradiol$ and progesterone were effective in pseudopregnant rat oviduct. In the ovary intact group the ALPase activity was similar in both of normal and pseudopregnant oviduct, but in the $17{\beta}-estradiol$ treated group the ALPase activity in normal pregnancy was significantly higher than that in pseudopregnancy. The effect of estradiol on the normal pregnant rat oviduct was apparently found on day 3 and day 9 pregnancy. This study, therefore, clearly demonstrates that $17{\beta}-estradiol$ is much potent in oviduct tissue differentiation. It is suggested that absence of $17{\beta}-estradiol$ effect on pseudopregnant rat oviduct is due to there is no embryo passing througth the oviduct.

• Clinical and Experimental Reproductive Medicine
• /
• v.38 no.3
• /
• pp.119-125
• /
• 2011

Implantation of an embryo occurs during the mid-secretory phase of the menstrual cycle, known as the "implantation window." During this implantation period, there are significant morphologic and functional changes in the endometrium, which is followed by decidualization. Many immune cells, such as dendritic and natural killer (NK) cells, increase in number in this period and early pregnancy. Recent works have revealed that antigen-presenting cells (APCs) and NK cells are involved in vascular remodeling of spiral arteries in the decidua and lack of APCs leads to failure of pregnancy. Paternal and fetal antigens may play a role in the induction of immune tolerance during pregnancy. A balance between effectors (i.e., innate immunity and helper T [Th] 1 and Th17 immunity) and regulators (Th2 cells, regulatory T cells, etc.) is essential for establishment and maintenance of pregnancy. The highly complicated endocrine-immune network works in decidualization of the endometrium and at the fetomaternal interface. We will discuss the role of immune cells in the implantation period and during early pregnancy.

• Molecules and Cells
• /
• v.22 no.3
• /
• pp.262-268
• /
• 2006

During endometrial differentiation the extracellular matrix (ECM) changes dramatically to prepare for implantation of the embryo. However, the genes regulating the ECM build-up in the uterine endometrium during early pregnancy are not well known. Using the PCR-select cDNA subtraction method, dermatopontin was identified in the uterus of a pregnant mouse on day 4 of gestation. Dermatopontin mRNA increased dramatically on day 3, and was at its highest level at the time of implantation. Administration of RU 486 significantly inhibited mRNA expression by day 4 of gestation, but ICI 182,780 did not. Progesterone markedly induced dermatopontin expression in ovariectomized uteri within 4 h of administration, whereas estrogen had little effect. In silico analysis revealed progesterone receptor binding sites in the dermatopontin promoter region. Decidualization did not induce expression of dermatopontin; instead dermatopontin mRNA became strongly localized at the interimplantation site. In situ hybridization revealed that expression gradually decreased in the luminal epithelial cells as pregnancy progressed, whereas it increased in the stromal cells. The pattern of localization and the changes of intensity of dermatopontin mRNA coincided with those of collagen. Collectively, these results strongly suggest that dermatopontin expression is steroid-dependent. They also suggest that, at the time of implantation, dermatopontin expression is primarily regulated spatio-temporally by progesterone via progesterone receptors, and is modulated by the decidual response during implantation. Dermatopontin may be one of the regulators used to remodel the uterine ECM for pregnancy.

• Clinical and Experimental Reproductive Medicine
• /
• v.48 no.4
• /
• pp.273-282
• /
• 2021

Since December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly, resulting in a pandemic. The virus enters host cells through angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine subtype 2 (TMPRSS2). These enzymes are widely expressed in reproductive organs; hence, coronavirus disease 2019 (COVID-19) could also impact human reproduction. Current evidence suggests that sperm cells may provide an inadequate environment for the virus to penetrate and spread. Oocytes within antral follicles are surrounded by cumulus cells, which rarely express ACE2 and TMPRSS2. Thus, the possibility of transmission of the virus through sexual intercourse and assisted reproductive techniques seems unlikely. Early human embryos express coronavirus entry receptors and proteases, implying that human embryos are potentially vulnerable to SARS-CoV-2 in the early stages of development. Data on the expression of ACE2 and TMPRSS2 in the human endometrium are sparse. Moreover, it remains unclear whether SARS-CoV-2 directly affects the embryo and its implantation. A study of the effect of SARS-CoV-2 on pregnancy showed an increase in preterm delivery. Thus, vertical transmission of the virus from mother to fetus in the third trimester is possible, and further data on human reproduction are required to establish this possibility. Based on analyses of existing data, major organizations in this field have published guidelines on the treatment of infertility. Regarding these guidelines, despite the COVID-19 pandemic, reproductive treatment is crucial for the well-being of society and must be continued under suitable regulations and good standard laboratory practice protocols.

• 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.

• 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.

• Korean Journal of Animal Reproduction
• /
• v.23 no.4
• /
• pp.293-301
• /
• 1999

This study was to examine whether Hanwoo IVM/IVF/IVC blastocyst can be successfully survived in vitro/in vivo after vitrification and one-step dilution. For vitrification, blastocysts were serially exposed in glycerol (G) and ethylene glycol(EG) mixtures［10% (v Iv) G for 5 min., 10% G plus 20% EG (v/v) for 5 min., and 25% G plus 25% EG (v/v) for 30 sec.］ which is diluted in 10% FBS added D-PBS. And then they were loaded in the straw, placed in cold nitrogen vapor for 3 min. and plunged into L$N_2$(－196$^{\circ}C$). One-step dilution within the straw was done in $25^{\circ}C$ and 36$^{\circ}C$ water for about 5 min. and 3 min., respectively. Recovered embryos after one-step dilution were cultured in cumulus cell mono-layered drop for 48 h or were transferred into recipient cows. When the embryo survival in vitro was assessed to re-expanded and hatched rates at 24 hand 48 h after one-step dilution, the results of vitrified group (85.4, 43.8%) was high, although these results were significantly lower than normal development (100.0, 63.3%) of control group, respectively (P＜0.001, P＜0.05). When in vitro survival of vitrified groups according to developmental stage was compared, the results of fast developed embryos (expanded blastocyst and early hatching blastocyst stage) were significantly higher than those of delayed developed one (early blastocyst stage) after one-step dilution (early hatching: 88.0, 48.0%: expanded: 81.1, 45.3%; early: 66.7, 14.3%) (P＜0.05). Also, in case of in vitro survival of vitrified groups according to embryo age (day 7, 8 and 9), when embryo age was younger, in vitro survival was significantly higher (day 7: 67.3, 34.5%; day 8: 76.9, 40.7%; day 9: 60.9, 23.9%)(P＜0.05). Finally, when in vivo development potential of vitrified and one-step diluted Hanwoo blastocysts was examined, 4 of 8 recipient (50%) cows became confirmed pregnant. These results demonstrated that our vitrification and one-step dilution technique can be applied easily and effectively on field trial without the equipment and embryological skills required for conservative dilution and transfer.