• 한국패류학회지
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• 제32권1호
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• pp.37-43
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• 2016

This study was carried out to determine the optimal water temperature for the embryonic development and laboratory culture of larvae of an intertidal mud snail, Nassarius festivus. The embryos and hatched veliger larvae of N. festivus were incubated at six different temperatures (5, 10, 15, 20, 25 and $30^{\circ}C$). Developmental time for each stage decreased as water temperature increased. The elapsed time to develop to the veliger larva at 15, 20, 25 and $30^{\circ}C$ was 559, 155, 131 and 103 hrs, respectively. At 5 and $10^{\circ}C$, embryo developed to veliger larvae but failed to hatch out of the egg capsule. In contrast, all embryos successfully hatched in the temperature range from 15 to $30^{\circ}C$. The biological minimum temperature during the embryonic development of N. festivus was estimated to be $9.5{\pm}0.4^{\circ}C$. The cumulative water temperatures for blastula, gastrula and veliger stages were calculated as $111{\pm}84$, $486{\pm}185$, $1,164{\pm}72^{\circ}C$, respectively. Temperature also affected the larval survival. Five days after hatching, more than 84% of larvae survived at all experimental temperatures. However, survival began to decrease after 6 days. It was 0% at $30^{\circ}C$. Survival of larvae incubated for 8 days was higher at 15 and $20^{\circ}C$ than other experimental temperatures. We therefore suggest that the optimal range of temperature for embryonic development and larval survival of N. festivus is $15-20^{\circ}C$.

• Archives of Pharmacal Research
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• 제28권9호
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• pp.1057-1064
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• 2005

Apoptosis may occur in early embryos where the execution of essential developmental events has failed, and gangliosides, sialic acid-conjugated glycosphingolipids, are proposed to regulate cell differentiation and growth. To evaluate the regulatory roles of ganglioside GM3 in early embryonic development, this study examined its expressional patterns in apoptotic cells during early embryonic development in mice. Pre-implanted embryos were obtained by in vitro fertilization, which were treated at the 4-cell stage with three the apoptosis inducers, actinomycin D, camptothecin and cycloheximide, for 15 h. All three inducers significantly increased the percentage of apoptotic cells, as measured using a TUNEL method, but remarkably reduced the total cell numbers. The numbers of morula and blastocyst stages were significantly decreased by treatment of the embryos with the three apoptosis inducers compared with the control, with a similar result also observed in the number of blastomeres. Staining of early embryos with Hoechst 33342 revealed a significant percentage of apoptotic nuclei. Prominent immunofluo­rescence microscopy revealed a significant difference in the ganglioside GM3 expression in apoptotic embryos compared with the control, and RT-PCR also demonstrated a dramatic increase in ganglioside GM3 synthase mRNA in the apoptotic embryos. These results suggest that ganglioside GM3 may be pathophysiologically implicated in the regulation of early embryonic development through an apoptotic mechanism.

• 한국발생생물학회지:발생과생식
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• 제24권3호
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• pp.207-214
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• 2020

Primary cell culture is a sufficient method frequently used to study the cellular properties and mechanisms of isolated cells in a controlled environment. In this study, an embryonic cell line (FGBC8) derived from the blastula stages of embryos of olive flounder Paralichthys olivaceus was developed. Furthermore, conditions for optimal long-term maintenance of this primary embryonic cell culture were investigated. Morphologically, FGBC8 cells were composed primarily of epithelial-like cells. FGBC8 cells were subcultured for >160 passages over ~830 days. The doubling time of FGBC8 cells was 73.8 h, and the modal diploid chromosome number was 48. FGBC8 cells transfected with green fluorescence protein (GFP)-expression plasmid exhibited a strong signal 48 h after transfection. Consequently, we demonstrated that fish serum is a crucial supplement for the long-term survival and maintenance of comparable morphology in these primary embryonic cells. Our results can be used as a guide for primary embryonic cell cultures for other fish species and may be useful for cell biotechnological applications.

• Reproductive and Developmental Biology
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• 제36권3호
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• pp.167-172
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• 2012

The key regulators of apoptosis are the interacting protein of the Bcl-2 family. Bcl-2, an important member of this family, blocks cytochrome C release by sequestering pro-apoptotic BH3-only proteins such as Bid, Bad, Bax and Bim. The pro-survival family members (Bcl-2, Bcl-XL, Bcl-W) are critical for cell survival, since loss of any of them causes cell death in certain cell type. However, its role during early porcine embryonic development is not sufficient. In this study, we traced the effects of Bcl-2 inhibitor, ABT-737, on early porcine embryonic development. We also investigated several indicators of developmental potential, including gene expression (apoptosis-related genes) and apoptosis, which are affected by ABT-737. Porcine embryos were cultured in the PZM-3 medium with or without ABT-737 for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without ABT-737 ($14.7{\pm}3.0$ vs $30.3{\pm}4.8%$, p<0.05). TUNEL assay showed that the number of containing fragmented DNA at the blastocyst stage increased in the ABT-737 treated group compared with control (4.7 vs 3.7, p<0.05). The mRNA expression of the pro-apoptotic gene Bax increased in ABT-737 treated group (p<0.05), whereas expressions of the anti-apoptotic Bcl-2 family members (Bcl-2, Bcl-XL, Bcl-W) decreased (p<0.05). Also, expressions of the ER stress indicator genes (GRP78, XBP-1 and sXBP-1) increased in ABT-737 treated group (p<0.05). In conclusion, Bcl-2 is closely associated with of apoptosis- and ER stress-related genes expressions and developmental potential in pig embryos.

• 한국수정란이식학회지
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• 제6권2호
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• pp.1-17
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• 1991

It is widely recognized that the embryonic or fetal loss after breeding is common in the cattle and that it is an important factor affecting reproductive efficiency. The causes of this loss have been subject of extensive researches and the results indicate that the embryonic mortality may he primary factor responsible for low pregnancy rates in non-embryo transfer bovine populations as well as embryo transfer programs. However, it's causes are still not clearly understood. The embryonic mortality or pregnancy rate has been influenced by various embryonic and maternal effects related to genetic and environmental factors. The timing and extent of embryonic mortality vanes greatly according to authors and estimating methods, because it is difficult to make direct measurements. The major important factors that may influence the embryonic losses or pregnancy rates after embryo transfer can be summeirized. 1.When an embryo is transferred to unmated recipients, the contralateral transfer to corpus luteum results in a lower survival rate than ipsilateral deposition. When the embryos are transferred for the production of twin calves, their survivals and twin pregnancies have quite inconsistent according to the transfer methods either to the unmated-synchronized or already mated recipients and more works are needed to accurrately clarify the previous results. 2.Although embryos can be cultured in vitro some hours without the great declines in pregnancy rates, the rates differ markedly among culture times and media but may be improved by co-transfer systems. 3.Embryo developmental stages and quality grades clearly affect the survival rate following freezing and the pregnancy rate after transfer and the selection of embryos without chromosome abnormalities and of high fertile semen may also be considered to increase the pregnancy rates. 4.Many researches have attempted to relate the plasma progesterone levels to pregnancy rates and others have done either direct progesterone supplementation or luteal stimulation by hCG treatment in order to increase the pregnancy rates. However, these effects on pregnancy rates are inconsistent and also contradictory. 5.The asynchrony between donors or embryos and recipients may he a major cause of embryo death and low pregnancy rate and the sensitivity to uterine asynchyony differs in according to the quality and stages of embryos. 6.The extremes of poor or over nutrition during early pregnancy in the recipients are detrimental to the survival of embryos and the good body condition is required to prevent a reduejion of pregnancy rates. The uterine pathogens in embryonic mortality or fertility have been questioned but the infection of C.pyogenes and Campylobacter fetus is still important pathogens. 7.The heat stress during early pregnancy may reduce conceptus weight and possibly increase the embryonic mortality.

• Reproductive and Developmental Biology
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• 제38권1호
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• pp.41-52
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• 2014

Embryonic genome activation (EGA) is a highly complex phenomenon that is controlled at various levels. New studies have ascertained some molecular mechanisms that control EGA in several species; it is apparent that these same mechanisms regulate EGA in all species. Protein phosphorylation, DNA methylation and histone modification regulate transcriptional activities, and mechanisms such as ubiquitination, SUMOylation and microRNAs post-transcriptionally regulate development. Each of these regulations is highly dynamic in the early embryo. A better understanding of these regulatory strategies can provide the possibility to improve the reproductive properties in mammals such as pigs, to develop methods of generating high-quality embryos in vitro, and to find markers for selecting developmentally competent embryos.

• 한국발생생물학회지:발생과생식
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• 제13권3호
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• pp.155-161
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• 2009

It has been reported that ganglioside GT1b is expressed during neuronal cell differentiation from undifferentiated mouse embryonic stem cells (mESCs), which suggests that ganglioside GT1b has a direct effect on neuronal cell differentiation. Therefore, this study was conducted to evaluate the effect of exogenous addition of ganglioside GT1b to an in vitro model of neuronal cell differentiation from undifferentiated mESCs. The results revealed that a significant increase in the expression of ganglioside GT1b occurred during neuronal differentiation of undifferentiated mESCs. Next, we evaluated the effect of retinoic acid (RA) on GT1b-treated undifferentiated mESCs, which was found to lead to increased neuronal differentiation. Taken together, the results of this study suggest that ganglioside GT1b plays a crucial role in neuronal differentiation of mESCs.

• Animal cells and systems
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• 제2권1호
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• pp.123-131
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• 1998

The unc-29 region on the chromosome I of Caenorhabditis elegans has been mutagenized in order to obtain lethal mutations. In this screen, the uncoordinated phenotype of unc-29 (e193) mutant was used to identify any lethal mutations closely linked to the unc-29 gene, which encodes a subunit of nicotinic acetylcholine receptors. We have isolated six independent mutations (jh1 to jh6) out of approximately 5,200 ethyl methanesulfonate(EMS) treated haploids. Four of the six mutations demonstrated embryonic lethal phenotypes, while the other two showed embryonic and larval lethal phenotypes. Terminal phenotypes observed in two mutations (jh1 and jh2) indicated developmental defects specific to posterior part of embryos which appeared similar to the phenotypes observed in nob (no back end) mutants. Another mutation (jh4) resulted in an interesting phenotype of body-wall muscle degeneration at larval stage. These mutations were mapped by using three-factor crosses and deficiency mutants in this region. Here we report genetic analysis and characterization of these lethal mutations.

• Reproductive and Developmental Biology
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• 제36권4호
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• pp.275-281
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• 2012

Embryonic stem cell-preconditioned microenvironment is important for cancer cells properitities by change cell morphology and proliferation. This microenvironment induces cancer cell reprogramming and results in a change in cancer cell properties such as differentiation and migration. The cancer microenvironment affects cancer cell proliferation and growth. However, the mechanism has not been clarified yet. Using the ES-preconditioned 3-D microenvironment model, we provide evidence showing that the ES microenvironment inhibits proliferation and reduces oncogenic gene expression. But ES microenvironment has no effect on telomerase activity, cell viability, cellular senescence, and methylation on Oct4 promoter region. Furthermore, methylation of Nanog was increase on ES-preconditioned microenvironment and supports results that no difference on RNA expression levels. Taken together, these results demonstrated that in the ES-preconditioned 3-D microenvironment is a crucial role for cancer cell proliferation not senescence.

• Reproductive and Developmental Biology
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• 제38권4호
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• pp.137-142
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• 2014

A tremendous increase in the human population has put poultry industry under an increased pressure to meet steep increase in the demand. Poultry is contributing 25% of the total world's meat production and lesser cost of investment per bird makes it more suitable for the further breeding programmes. Major poultry diseases frequently lead to cardiac damage and cause huge economic losses to poultry industry due to mortality. The in vitro embryonic stem cell (ESC) technology has a futuristic approach for homogeneous populace of differentiated cells, for their further transplantations. During in vitro conditions the differentiated cell populace can be used in grafting and transplantation processes to regenerate damaged tissues. Therefore, the current study targeted the use of spermatogonial stem cells (SSCs) in the poultry production system through cardiac regeneration. The current study will also open new boulevard for the similar kind of research in other livestock species for the management of heart diseases.