• 한국발생생물학회지:발생과생식
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• 제20권2호
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• pp.127-133
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• 2016

Purine metabolism is known factor for nuclear maturation of oocytes through both follicle cells and oocyte itself. However, it is largely unknown the roles of purine metabolism in the oocyte competence for fertilization and early development. In this study, the effects of adenosine in oocyte competence for development were examined using adenosine and its synthetic inhibitors. Adenosine treatment from GV intact stage for 18 hr (fGV) caused of decrease the fertilization rate but of increase the cleavage rate compared from the other stage treatment groups. Hadacidin did not effect on fertilization rate but increased cleavage rate without stage specificity. Adenosine did not block the effects of hadacidin with the exception of fGV group. Inhibition of purine synthetic pathways the fertilization rate was decreased in the fGV and fGVB groups but increased in the fMII group. Exogenous adenosine caused of decrease fertilization rate in the fGVB group but increase in the fMII group. Cleavage rate was dramatically increased in the adenosine treatment with synthetic inhibitors. It means that the metabolism of purine has stage specific effects on fertilization and cleavage. Exogenous adenosine had only can improve oocyte developmental competence when it treated at GV intact stage. On the other hand, endogenous synthesis in all maturation stage cause of increase the cleavage rate without effects on fertilization. These data suggest that adenosine at GV stage as a paracrine fashion and inhibitions of endogenous adenosine in all stage improve oocyte developmental competence.

• Reproductive and Developmental Biology
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• 제31권2호
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• pp.71-76
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• 2007

Previous studies have shown that BMI-1026 is a potent inhibitor of the cyclin-dependent kinases (cdk). In cell culture, the compound also arrests G2/M strongly and G1/S and S weakly. Two key kinases, cdk1 (p34cdc2 kinase) and mitogen-activated protein (MAP) kinase (erk1 and 2), perform crucial roles during oocyte maturation and, later, metaphase II (MII) arrest. In mammalian oocytes, both kinases are activated gradually around the time of germinal vesicle breakdown (GVBD) and maintain high activity in eggs arrested at metaphase II. In this study, we examined the effects of BMI-1026 on GVBD and MII arrest in mouse oocytes. BMI-1026 inhibited GVBD of immature oocytes and activated MII-arrested oocytes in a concentration-dependent manner, with more than 90% of oocytes exhibiting GVBD inhibition and MII activation at 100 nM This is approximately 500$\sim$1,000 times more potent than the activity reported for the cdk inhibitors roscovitine (${\sim}50{\mu}M$) and butyrolactone (${\sim}100{\mu}M$). Based on the results of previous in vitro kinase assays, we expected BMI-1026 to inhibit only cdk1 activation in oocytes and eggs, not MAP kinase. However, in our cell-based system, it inhibited the activity of both kinases. We also found that the effect of BMI-1026 is reversible. Our results suggest that BMI-1026 inhibits GVBD and activates MII-arrested oocytes efficiently and reversibly and that it also inhibits both cdk1/histone HI kinase and MAP kinase in mouse oocytes.

• Reproductive and Developmental Biology
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• 제30권2호
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• pp.107-113
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• 2006

Development of placenta is a complex process that is critical for the pregnancy and controlled by many factors including cytokines, hormones, growth factors and apoptotic molecules. Recently, it has been shown that progranulin (PGRN) functions in growth of embryo and trophectoderm as well as cell migration. To initiate understanding the role of PGRN in human placental development, we investigated the expression of PGRN mRNA and protein in early and late gestation human placentas, term cytotrophoblast cells and two choriocarcinoma cell lines, JEG-3 and Jar. Reverse transcriptase polymerase chain reaction identified mRNAs derived from the PGRN gene in all samples. Immunoblot analysis showed that PGRN proteins are present in early and late gestation human placentas with decreasing levels over gestation and that PGRN proteins are present in normal and transformed trophoblast cells. Immunohistochemical analysis using paraformaldehyde-fixed tissue sections taken from early and late stages of pregnancy showed that PGRN proteins are present in cytotrophoblast cells, syncytiotrophoblast and extravillous cytotrophoblast cells and that expression pattern of PGRN differed according to the stage of cell differentiation. The results of this study are consistent with the hypothesis that PGRN proteins have critical roles in placental development and suggest that PGRN may function in trophoblast cell growth and differentiation.

• 한국발생생물학회지:발생과생식
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• 제15권1호
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• pp.1-7
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• 2011

It is suggested that FGF/Ras/MEK/Erk signaling plays crucial roles in specification and cell division of the mesodermal precursor cells in ascidian embryos. To investigate how the number of cell division in tissue precursor cells is determined, we have characterized Wee1 homolog, Hr-Wee1 of the ascidian Halocynthia roretzi. We found that the Hr-Wee1 mRNA is expressed both maternally and zygotically. Maternal transcript is localized to the cytoplasm in the animal cells, while zygotic expression is seen in cells of the endoderm lineage from 32-cell to 110-cell stages. Zygotic in situ signal is detected in the A-line neural plate cells of neurulae, and in epidermal cells of the head region of tailbud embryos. Embryos treated with MEK signaling inhibitor showed a similar pattern to normal embryos in expression of Hr-Wee1. Therefore, it is likely that MEK signaling does not affect the maternal and zygotic expression of Hr-Wee1.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2000년도 국제심포지움
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• pp.5-6
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• 2000

Nitric oxide (NO) is a simple combined molecule of oxygen and nitrogen, and has a wide variety of action on the physiological and pathophysiological function of the body. It is a key transducer of the vasodilator message from the endothelium to vascular cells. However, its different roles have been elucidated by numerous researches, which was undertaken in the 80's and 90's. Three types of NO synthase were involved in synthesizing NO and they are identified in different tissues and cells including macrophage, endothelial cells and even tumor cells. In the late 90's, we undertook a number of researches for elucidating the effect of NO on embryo development, since developmentally arrested bovine embryos contained large amount of NO metabolites in their cytoplasm. Subsequently, we found that the addition of a spontaneous NO donor to culture medium markedly inhibited embryo development and that its inhibitory role was independent of embryonic genome activation. Research was focused to find a way to prevent the inhibitory action of NO on embryo development and demonstrated that the addition of hemoglobin, a NO scavenger, to embryo culture medium greatly stimulated in vitro-development of bovine and mouse embryos. Based on these research outcomes, we developed a NO action-free culture system for embryos and other tissues. The efficacy of such system has subsequently been confirmed by achieving the high rates of preimplantation development and blastocyst formation in the NO action-free culture of mouse and bovine embryo. In this article, we briefly introduced the nature of NO and our research outcomes on the role of NO in embryo development.

• Reproductive and Developmental Biology
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• 제38권1호
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• pp.21-34
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• 2014

The majority of early embryonic mortality in pregnancy occurs during the peri-implantation stage, suggesting that this period is important for conceptus viability and the establishment of pregnancy. Successful establishment of pregnancy in all mammalian species depends on the orchestrated molecular events that transpire at the conceptus-uterine interface during the peri-implantation period. This maternal-conceptus interaction is especially crucial in pigs because in them non-invasive epitheliochorial placentation occurs, in which the pre-implantation phase is prolonged. During the pre-implantation period, conceptus survival and the establishment of pregnancy are known to depend on the developing conceptus receiving an adequate supply of histotroph, which contains a wide range of nutrients and growth factors. Evidence links growth factors including epidermal growth factor (EGF), insulin-like growth factor-I (IGF-I), vascular endothelial growth factor (VEGF), and colony-stimulating factor 2 (CSF2) to embryogenesis or implantation in various mammalian species; however, in the case of pig, little is known about such functions of these growth factors, especially their regulatory mechanisms at the maternal-conceptus interface. Our research group has presented evidence for promising growth factors affecting cellular activities of primary porcine trophectoderm (pTr) cells, and we have identified potential intracellular signaling pathways responsible for the activities induced by these factors. Therefore, this review focuses on promising growth factors at the maternal-conceptus interface regulating the development of the porcine conceptus and playing pivotal roles in implantation events during early pregnancy in pigs.

• 한국발생생물학회지:발생과생식
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• 제13권1호
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• pp.13-23
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• 2009

최근에 이루어진 세포생물학적, 유전학적 연구들을 통하여 미토콘드리아의 구조 변화가 매우 역동적이며, dynamin- related protein(DRP)와 같은 다양한 단백질에 의해 조절된다는 것이 알려지게 되었다. 미토콘드리아가 ATP 합성을 통한 세포내 신진대사에 관여하며, 소포체와 상호작용을 통하여 칼슘 이온 농도의 항상성 유지, 그리고 세포 사멸에서 중요한 역할을 한다는 사실을 고려해 볼 때, 미토콘드리아 구조 역동성 조절은 정상적인 세포의 성장과 항상성 유지와 매우 밀접한 관계에 있다. 이러한 점에서, 미토콘드리아의 구조 역동성 변화가 신경세포의 발달에 큰 영향을 줄 것으로 생각된다. 이 논문에서는 미토콘드리아의 구조 역동성을 조절하는 단백질들을 소개하고, 신경세포의 발달과정에서 미토콘드리아의 구조 역동성 조절의 중요성에 대하여 전망하고자 한다.

• 환경생물
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• 제39권2호
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• pp.160-168
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• 2021

Doublesex and mab-3 related transcription factor(dmrt) play crucial roles in sex determination and sex differentiation in vertebrates and invertebrates. Although dmrt genes have been identified in vertebrates, little is known about aquatic invertebrates. In this study, two dmrt genes, namely, Dc_dmrt93B and Dc_dmrt99B, were identified from brackish water flea, Diaphanosoma celebensis. Transcriptional changes were observed in the dmrt genes when the flea was exposed to bisphenol(BP), an endocrine disruptor. Sequence and phylogenetic analyses showed that both dmrt genes contained two conserved domains, namely, DM and DMA, closely clustered with those of Daphnia spp. Additionally, a significant increase in the Dc_dmrt99B mRNA expression level was observed upon exposure to intermediate concentrations of BP (bisphenol A>bisphenol S=bisphenol F, p<0.05), while the expression of Dc_dmrt93B mRNA was slightly modulated. These findings imply that the two dmrt genes may be involved in sex differentiation of D. celebensis. Furthermore, it was found that the ability of BP to modulate dmrt genes could affect development and reproduction. This study provides a basis for understanding the function of the dmrt genes and the molecular mode of action of BP in small crustaceans.

• Reproductive and Developmental Biology
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• 제35권3호
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• pp.209-214
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• 2011

Although the function and utility of RNA transcripts derived from matured spermatozoa remains unclear, they might play important roles in the establishment of a paternal genome and subsequently embryo development. Herein, we investigated the expression of X-chromosome linked RNA transcripts in matured bovine spermatozoa. The total RNA was extracted from the matured spermatozoa, and then converted to cDNA. Autosomal genes (ACT-${\beta}$ and H-2A) and X-chromosome linked genes (ANT3, HPRT, MeCP2, RPS4X, XIAP, XIST and ZFX) were analyzed for the characterization of X-chromosome linked RNA transcripts and compared to female fibroblasts by RT-PCR. The transcripts of autosomal genes (ACT-${\beta}$ and H2A) and X-chromosome linked genes (ANT3, HPRT, MeCP2, RPS4X and ZFX) were not detected in spermatozoa. However, XIAP (X-linked inhibitor of apoptosis protein) and XIST (X-chromosome inactive-specific transcript, a kind of paternal imprinted gene) transcripts were detected in spermatozoa, and relative levels of XIAP and XIST transcripts were similar and 0.5-fold lower when compared to female fibroblasts, respectively. Based on the findings, it is summarized that the presence of RNA transcripts of XIAP and XIST in the isolated spermatozoa may imply their role in inhibition of apoptosis and induction of X-chromosome inactivation in embryo development.

• Animal cells and systems
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• 제9권1호
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• pp.13-18
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• 2005

Cannibalism plays important roles at the levels of both individual and population. To enhance overall rate of successful survival and reproduction, salamander larvae may have evolved to consume both conspecifics and heterospecifics. Consuming conspecifics could result in decreased inclusive fitness possibly by killing relatives. In several salamander species, discrimination of salamander larval siblings from non-siblings and heterospecifics to avoid such a risk has been reported. To determine whether the Korean salamander larvae consume non-siblings more often than siblings and to analyze prey preferences of the salamander larvae in several different experimental conditions, a series of foraging experiments was conducted in the laboratory. We found that 1) large cannibal larvae preyed on small sibling more often than small non-sibling in a mixed group of sibling and non-sibling, 2) cannibal larvae prefered to consume live, weak, and small larvae to dead, healthy, and large larvae, and 3) cannibal larvae consumed heterospecific tadpoles more often than conspecific nonsibling larvae in a mixed group. In addition, the larval density was positively correlated with the occurrence of spacing behavior, one of the agonistic predator behaviors among salamander larvae.