• Journal of the Korean Geographical Society
• /
• v.39 no.3
• /
• pp.391-408
• /
• 2004

Modernism is understood as a process of differentiation. Postmodernism or postmodernity, by contrast, involves de-differentiation. There is a breakdown in the distinctiveness of each of spheres of social activities. It is important to explain an examination of the relationships between the de-differentiation and a wide variety of contemporary tourism, expecially postmodern tourism. Also, de-differentiation between the tourism and the social spheres lead to the spatial reflection. Aim of this paper is to examine the processes of de-differentiation between the tourism and the social spheres, which comes out spatially in Jeju island. Especially, location of destinations is concentrated on the coastline in the period of modem tourism. On the contrary, the postmodern tourism shows that the location of destinations are wide spread diffusion its vertically and horizontally. It means that there are to appear a breakdown of distinctiveness between the conventional tourism destinations and the regional person's space.

• Journal of Life Science
• /
• v.21 no.4
• /
• pp.534-541
• /
• 2011

Retinoic acid (RA), a metabolite of vitamin A, is known to regulate dedifferentiation of rabbit articular chondrocytes. The regulatory mechanism of dedifferentiation by RA is not yet understood. Thus, the effect of RA on the regulation of nitric oxide (NO)-induced dedifferentiation was investigated in rabbit articular chondrocytes. RA caused loss of the differentiated chondrocyte phenotype as demonstrated by inhibition of type II collagen expression and proteoglycan synthesis. RA also accelerated NO-induced dedifferentiation in rabbit articular chondrocytes as detected by expression of type II collagen and Sox-9 using Western blot analysis and production of sulfated proteoglycan using Alcain blue staining. Further, RA potentiated NO-induced activation of ERK. Inhibition of ERK with PD98059 (PD) recovered the expression of type II collagen and Sox-9 and production of sulfate proteoglycan in NO-induced dedifferentiated chondrocytes by RA treatment. Our findings suggest that RA accelerates NO-induced dedifferentiation of rabbit articular chondrocytes via the ERK pathway.

• The Korean Journal of Zoology
• /
• v.39 no.1
• /
• pp.65-74
• /
• 1996

Treatment of regenerating amphibian limbs with retinoic acid (RA) is known to induce paftern duplication, which is closely related to the extent of dedifferentiation. In the present study, the activities of trypsin- and chymotrypsin-like proteases are examined to delineate a possible role in the process of dedifferentiation in the regenerating limbs of urodeles, the Korean salamander (Hynobius leechii) and the Mexican axolod (Ambystoma mexicanum). Specifically, we were interested to know if there is any correlation between trypsin- and chymotrypsin-like protease activities and the state of dedifferentiation which is augmented by RA treatment. We were also interested in expoloring if there is any species-specific difference in the profile of enzyme activities during limb regeneration. The results showed that the activities of these two enzymes reached a peak level at dedifferentiation stage, and RA treatment caused elevation of their activities, especially in the case of trypsin-like protease. The increase of trypsin-like protease activity after RA treatment was pronounced in the Korean salamander, which might reflect a species-specific responsiveness to RA. The present results imply that trypsin and chymotrypsin or similar proteases may play an active role in the process of dedifferentiation in regenerating limbs, and that trypsin or trypsin-like eryrymes might be involved in the RA-evoked enhancement of dedifferentiation which precedes overt pattern duplication.

• Journal of the Korean association of regional geographers
• /
• v.10 no.4
• /
• pp.833-850
• /
• 2004

Modernism is understood as a process of differentiation. Postmodernism or postmodernity, by contrast, involves de-differentiation. Recently, most museums have many social function, a central defining feature is its 'inscapes', or the spaces, architecture, material objects, texts, and meanings of exhibitions. Aims of this paper is to examine the processes and characteristics of differentiation and de-differentiation of the korean museums in historical development. The processes of differentiation and de-differentiation of the korean museums are divided into three phases: a establish stage of modem museum(l945$\sim$1974), a establish stage of postmodern museum(1975$\sim$1989), a diffusion stage of postmodern museum(1990$\sim$2003).

• The Korean Journal of Zoology
• /
• v.39 no.4
• /
• pp.426-436
• /
• 1996

In previous studies, we have shown that lysosomal add phosphatase (LAP) activity increases at the dedifferentiation stage in the regenerating larval limbs of salamander, Hynobius leechii. Monoclonal antibodies against LAP were generated to determIne the spatial and temporal distribution of the protein In the regenerates.A total of 22 monoclonal antihodies recognizIng different epftopes of the protein were obtained, of which five strongly stained the regenerating limb by imunohistochemistry. in LAP immunohistochemical examination, LAP showed distribution coincident with the state of dedifferentiation, both spatially and temporally, in the limb regenerates. When unfractioned protein of regenerating salamander limbs were separated by gel electrophoresis and immunoblotted, the antibodies recognized a single protein band of 53 kl)a, which comigrates with a monomerlc subunit of IAR Using the anti-IAP antibodIes as probe, we investigated the cross-reactivities of LAPs from other sources. The immunoreadive bands on Western blots appeared to be the same In molecular mass-53 kl)a in axoloti and Xenopus, but no protein band was detected in mouse, Drosophila, or C. elegans.These results show that the antibodies generated in this study spedfically recognize Hynoblus leeclili IAp and that IAPs may be highiy conserved among amphibians. Furthermore, the distdbution of the protein is consistent with a role for LAP in the dedifferentiation process of limb regeneration.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2023.04a
• /
• pp.34-34
• /
• 2023

화본과 식물인 홍띠(Imperata cylindrica 'Rubra') 식물체의 기관분화 단계별 시료를 작성하여 이들 몇가지 기관분화에 관련된 유전자의 각 단계별 기관분화체에서 유전자존재와 발현여부를 조사하였다. 또한 식물의 기관분화에 관련된 유전자 정보를 얻기 위하여 일부 유전자의 특성을 정리하였다. 조사된 기관분화 관련 유전자중 탈분화 관련 유전자로는 FIF, RAP2-4 (WIND1) 유전자 등이, shoot 분화 관련 유전자로는 WUS, 부정근 분화관련 유전자로는 OsSCR, WOX11 등, 체세포배발생 관련 유전자로는 BBM1, SERK1, LEC1B, MEA 유전자 등이다. 이들 유전자중 RAP2-4(WID1), FIE, BBM1, SERK1, OsSCR, WOX11, WUS, LEC1B 유전자 등 8종의 기관분화 관련 유전자를 대상으로 화본과 식물의 기관분화의 각 단계별 기관분화체를 작성하여 PCR을 통하여 유전자(gDNA)의 존재여부를 확인한 결과 공시 유전자 모두 홍띠의 각단계 기관분화체에서 존재하였다. 또한 상기 유전자를 사용하여 화본과 식물의 각단계별 기관분화체에 대하여 유전자 발현을 확인한 결과 각단계 기관분화체에서 모두 발현하였다. 5종류 총 15개체의 기관분화 단계별 분화체에서 캘러스 발생 유전자인 FIE는 모식물체 1번을 제외한 14개의 식물체에서 모두 관찰되었으며, 뿌리 발생 유전자인 WOX11은 15개의 모든 식물체에서 탐색되었으며, 체세포 발생 유전자인 LEC1B는 15개 식물체에서 모두 발현하였으나 비교적 약하게 발현하였다. 이상과 같이 본 연구에서는 식물 기내발생시 기관분화관련 유전자의 동향을 파악하여 식물발생학의 기초자료를 구축하고자 하였다.

• Journal of Life Science
• /
• v.27 no.3
• /
• pp.370-381
• /
• 2017

Protein dephosphorylation is important for cellular regulation, which is catalyzed by protein phosphatases. Among protein phosphatases, carboxy-terminal domain (CTD) phosphatases are recently emerging and new functional roles of them have been revealed. There are 7 CTD phosphatases in human genome, which are composed of CTD phosphatase 1 (CTDP1), CTD small phosphatase 1 (CTDSP1), CTD small phosphatase 2 (CTDSP2), CTD small phosphatase-like (CTDSPL), CTD small phosphatase-like 2 (CTDSPL2), CTD nuclear envelope phosphatase (CTDNEP1), and ubiquitin-like domain containing CTD phosphatase 1 (UBLCP1). CTDP1 dephosphorylates the second phosphor-serine of CTD of RNA polymerase II (RNAPII), while CTDSP1, STDSP2, and CTDSPL dephosphorylate the fifth phosphor-serine of CTD of RNAPII. In addition, CTDSP1 dephosphorylates new substrates such as mothers against decapentaplegic homologs (SMADs), cell division cycle-associated protein 3 (CDCA3), Twist1, tumor-suppressor protein promyelocytic leukemia (PML), and c-Myc. CTDP1 is related to RNA polymerase II complex recycling, mitosis regulation and cancer cell growth. CTDSP1, CTDSP2 and CTDSPL are related to transcription factor recruitment, tumor suppressor function and stem cell differentiation. CTDNEP1 dephosphorylates LIPIN1 and is related to neural tube formation and nuclear envelope formation. CTDSPL2 is related to hematopoietic stem cell differentiation. UBLCP1 dephosphorylates 26S proteasome and is related to nuclear proteasome regulation. In conclusion, noble roles of CTD phosphatases are emerging through recent researches and this review is intended to summarize emerging roles of CTD phosphatases.

• Journal of Life Science
• /
• v.17 no.7 s.87
• /
• pp.976-982
• /
• 2007

The purpose of this study was to determine the modulating effects of histone deacetylase inhibitor, trichostatin A, on the differentiation of mouse C2C12 myoblasts. We demonstrated that trichostatin A induced morphological changes of C2C12 myoblasts into smooth muscles and significantly increased the gene expression of smooth muscle markers including smooth muscle ${\alpha}-actin$ and transgelin. These results were due to the change in the expression level of cell cycle regulators in trichostatin A-treated C2C12 cells. Real-time PCR data revealed that cyclin dependent kinase inhibitor, p21, mRNA expression was significantly increased in trichostatin A-treated C2C12 cells. However, trichostaDn A rapidly decreased cyclin Dl mRNA expression necessary for cell cycle progression in 24hr after treatment. In conclusion, the strong inhibitory effects of trichostatin A on histone deacetylation induced transdifferentiation of C2C12 myoblasts into smooth muscle cells and these results are partly due to the changes in the expression of cell cycle regulators such as p21 and cyclin D1.

• Development and Reproduction
• /
• v.2 no.1
• /
• pp.53-62
• /
• 1998

The lysosomal acid hydrolases including lysosomal acid phosphatase (LAP) are believed to play an important role in intracellular and extracellular degradation. LAP was reported to increase its activity in dedifferentiation stage during urodele limb regeneration. In the paresent study, LAP localization in the Mexican axolotl (Ambystoma mexicanum) limb regenerates was investigated by immunohistochemistry. LAP immunoreactivity with monoclonal antibody against Korean salamander (Hynobius leehii) LAP was observed mainly in the wound epidermis, blastema cells, muscle, and cartilage which were under dedifferentiation process in axolotl limb regenerates. Moreover, LAP immunoreactivity increased gradually during the early phase of lib regeneration and reached the peak level at dedifferentiation stage. However, as redifferentiation begans, LAP immunoreactivity decreased slowly to the basal level. Retinoic acid (RA) which is known to induce skeleton pattern duplication in regenerating urodele limb appears to enhance LAP immunoreactivity. In the RA-treate limg regenerates, LAP immunoreactivity was higher than in the normal regenerates. In addition, the LAP expression period was more extended in the RA treated regenerates than in the normal regenerates. These results suggest that RA is involved in the extension of dedifferentiation state in RA-treated limb regenerate.

• Proceedings of the Zoological Society Korea Conference
• /
• 1994.10a
• /
• pp.163.2-163
• /
• 1994