• 제목/요약/키워드: Molecular evolution

검색결과 529건 처리시간 0.025초

Quantitative evaluation of the molecular marker using droplet digital PCR

  • Shin, Wonseok;Kim, Haneul;Oh, Dong-Yep;Kim, Dong Hee;Han, Kyudong
    • Genomics & Informatics
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    • 제18권1호
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    • pp.4.1-4.6
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    • 2020
  • Transposable elements (TEs) constitute approximately half of Bovine genome. They can be a powerful species-specific marker without regression mutations by the structure variation (SV) at the time of genomic evolution. In a previous study, we identified the Hanwoo-specific SV that was generated by a TE-association deletion event using traditional PCR method and Sanger sequencing validation. It could be used as a molecular marker to distinguish different cattle breeds (i.e., Hanwoo vs. Holstein). However, PCR is defective with various final copy quantifications from every sample. Thus, we applied to the droplet digital PCR (ddPCR) platform for accurate quantitative detection of the Hanwoo-specific SV. Although samples have low allele frequency variation within Hanwoo population, ddPCR could perform high sensitive detection with absolute quantification. We aimed to use ddPCR for more accurate quantification than PCR. We suggest that the ddPCR platform is applicable for the quantitative evaluation of molecular markers.

새로운 동물계통 (New Animal Phylogeny)

  • Kim, Chang-Bae;Kim, Won
    • Animal Systematics, Evolution and Diversity
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    • 제17권2호
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    • pp.263-275
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    • 2001
  • 전통적인 동물의 계통수는 초기발생 형질들에 기초하여 몸 구조의 복잡성에 따라 동물문들을 단순한 동물에서 복잡한 동물 순으로 점진적으로 배열하는 것인데 현재 활발히 연구되는 분자계통 연구들이 이 경향을 재평가하고 새로운 계통과 의미를 제시하고 있다. 주로 18S rRNA 에 의한 분자계통에 의하면 무체강동물과 의체강동물과 같이 진체강동물로의 전이단계에 위치했던 무리들이 서로 나뉘어진 진체강동물 안에 속하게 된다. 이러한 새로운 분자계통은 좌우대칭동물의 공동조사에 대한 새로운 가정들을 세울 수 있는 뼈대와 비교발생학 및 비교유전체학 정보가 해석될 수 있는 토대를 제공한다.

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Molecular dynamics study on initial growth behavior of amorphous carbon film under various incidence angles

  • Joe, Min-Woong;Moon, Myoung-Woon;Lee, Kwang-Ryeol
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.310-310
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    • 2011
  • Morphological evolution of amorphous carbon film is investigated by molecular dynamics simulation. Here, energetic carbon atoms (75 eV) are deposited on the diamond (001) substrate to find effect of incidence angles. At normal and near-normal incidences ($0^{\circ}{\sim}30^{\circ}$) atomically smooth surfaces are observed during their growth. However, rough surfaces emerge and develop into a ripple structure at grazing incidences ($60^{\circ}{\sim}70^{\circ}$). The different growth modes according to the incidence angles can be described by impact-induced displacements of atoms. Downhill transport along any sloped surfaces is predominant for the case of normal incidence. As the incidence angles become grazing, uphill transport is allowed along the surfaces, which have smaller slopes than incidence angle, so the surface features can be amplified. Impact-induced transport and self-shadowing effect can be responsible to the initial growth of seeding structures at a grazing incidence, which would be grown up as tilted columnar structures in further depositions.

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The ISM properties under ICM pressure in the cluster environment : NGC4330, NGC4402, NGC4522, NGC4569

  • 이범현;정애리
    • 천문학회보
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    • 제37권2호
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    • pp.85.2-85.2
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    • 2012
  • The interstellar medium (ISM) of galaxies in the galaxy cluster can well be affected by the intracluster medium (ICM). Among many suggested environmental processes, ram pressure stripping can effectively remove gas through the interaction with the ICM. In fact, Cluster galaxies are lower in HI gas mass compared to their field counterparts, and in recent high resolution HI imaging studies, many galaxies in dense environments have been found to be ram pressure stripped in HI. However, it is still under debate whether the ICM pressure can also remove dense molecular gas from the galactic disk, which plays more important role in star formation and hence galaxy evolution. To answer this question, we have obtained high resolution 12/13 CO (2-1) data from the Sub Millimeter Array (SMA) of four galaxies at various HI stripping stages to study how the molecular gas properties change as the galaxy experiences the ICM pressure. We investigate the physical properties of molecular gas with 12/13 CO images. By comparing with other wavelength data, i.e. data(optical, HI, $H{\alpha}$, etc), we discuss how and in which timescale galaxies can migrate from the blue cloud to the red sequence due to ram pressure stripping.

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AKARI Observations for 8 dense molecular cores

  • 김관정;이창원;김미량;김성은
    • 천문학회보
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    • 제37권2호
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    • pp.100.1-100.1
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    • 2012
  • We present results of AKARI observations toward 8 dense molecular cores which are previously known to be "starless". These cores show some spectral features which may imply characteristic internal motions. The observations were carried out at 8 bands (3, 4, 7, 11, 65, 90, 140, and 160 micron) with IRC and FIS instruments equipped in the AKARI. The archive data of 2MASS and Spitzer were also utilized. We found that 1 (L1582A) of 8 cores has a few embedded young stellar objects (YSOs) while the rest of them are still starless. The YSOs found in L1582A are identified by the slope of the spectral energy distribution or by the AKARI color-color diagram. The unusually broad linewidth toward L1582A, which is twice broader than one of starless cores, is also consistent with the existence of protostars in this core. The physical environment and evolution of the other "starless" cores where any AKARI point source is not detected will be discussed with help of their molecular line observations.

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Tersoff 포덴셜을 이용한 Si(001) 미사면 거동에 대한 분자동력학적 연구 (Molecular Dynamics Simulation on the Behavior of Si(001) Vicinal Surface by Using Empirical Tersoff Potential)

  • 최정혜;차필령;이승철;오정수;이광렬
    • 대한금속재료학회지
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    • 제47권1호
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    • pp.32-37
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    • 2009
  • Molecular dynamic simulations on the structural evolution of the Si(001) vicinal surfaces, which are tilted with respect to [100] and [110] directions were performed by using the empirical Tersoff potential. Tersoff potential was implemented at LAMMPS code and confirmed to describe the properties of Si. When the steps are generated along [100] direction, symmetric dimer rows formed with respect to the step edges. On the other hand, when the steps are generated along [110] direction, alternating dimer rows form with respect to the step edges. The configurational differences between the two vicinal surfaces were discussed in terms of the surface diffusion and the possibility of preventing step bunching for the (001) vicinal surface tilted along [100] direction was suggested.

An NMR Study on Molecular Motions of $\alpha$,2,6-Trichlorotoluene in Solution State

  • Ahn, Sang-Doo;Lee, Jo-Woong
    • Bulletin of the Korean Chemical Society
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    • 제15권7호
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    • pp.553-559
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    • 1994
  • Dynamics of $CH_2CI$ group in ${\alpha},2,6$-trichlorotoluene dissolved in $CDCl_3$ was studied by observing various relaxation modes for $^{13}C$ under proton undecoupled condition. Partially relaxed $^{13}C$ spectra were obtained at $34^{\circ}C$ as a function of evolution time after applying various designed pulse sequences to this $AX_2$ spin system. It was found that nonlinear regression analysis of the relaxation data for these magnetization modes could provide the information about dipolar and spin-rotational auto-correlation and cross-correlation spectral densities for fluctuation of the $^{13}C-^1H$ internuclear vector in $CH_2Cl$ group. The results show that the effect of cross-correlation is comparable in magnitude to that of auto-correlation and the relaxation in this spin system is dominated by dipolar mechanism rather than spin-rotational one. From the resulting spectral density data we could calculate the bond angle ${\angle}HCH\;(105.1$^{\circ}$) and elements of the rotational diffusion tensor for $CH_2Cl$ group.

Genetic Diversity of Orobanche cumana Populations in Serbia

  • Ivanovic, Zarko;Marisavljevic, Dragana;Marinkovic, Radovan;Mitrovic, Petar;Blagojevic, Jovana;Nikolic, Ivan;Pavlovic, Danijela
    • The Plant Pathology Journal
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    • 제37권6호
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    • pp.512-520
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    • 2021
  • In this study, we report genetic characterization of Orobanche cumana, the causal agent of sunflower wilting in Serbia. The genetic diversity of this parasitic plant in Serbia was not studied before. Random amplified polymorphic DNA (RAPD) markers and partial rbcL gene sequences analysis were used to characterize the O. cumana populations at the molecular level. While phylogenetic analyses of RAPD-PCR amplicons were performed using unweighted pair-group Method analyses, rbcL gene sequences were analyzed using neigbor joining method and minimum spanning tree. Molecular analyses of RAPD-PCR analysis revealed high genetic diversity of O. cumana populations which indicated high adaptive potential of this parasitic weed in Serbia. Further analyses of rbcL gene using minimum spanning tree revealed clear differences among diverse sections of Orobanche genus. Although this molecular marker lacked the resolution to display intrapopulation diversity it could be a useful tool for understanding the evolution of this parasitic plant. Our results suggested that O. cumana has great genetic potential which can lead to differentiation of more virulent races which is important for determining crop breeding strategies for their control.

Comparative analysis of AGPase proteins and conserved domains in sweetpotato (Ipomoea batatas (L.) Lam.) and its two wild relatives

  • Nie, Hualin;Kim, Sujung;Kim, Jongbo;Kwon, Suk-Yoon;Kim, Sun-Hyung
    • Journal of Plant Biotechnology
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    • 제49권1호
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    • pp.39-45
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    • 2022
  • Conserved domains are defined as recurring units in molecular evolution and are commonly used to interpret the molecular function and biochemical structure of proteins. Herein, the ADP-glucose pyrophosphorylase (AGPase) amino acid sequences of three species of the Ipomoea genus [Ipomoea trifida, I. triloba, and I. batatas (L.) Lam. (sweetpotato)] were identified to investigate their physicochemical and biochemical characteristics. The molecular weight, isoelectric point, instability index, and grand average of hyropathy markedly differed among the three species. The aliphatic index values of sweetpotato AGPase proteins were higher in the small subunit than in the large subunit. The AGPase proteins from sweetpotato were found to contain an LbH_G1P_AT_C domain in the C-terminal region and various domains (NTP_transferase, ADP_Glucose_PP, or Glyco_tranf_GTA) in the N-terminal region. Conversely, most of its two relatives (I. trifida and I. triloba) were found to only contain the NTP_transferase domain in the N-terminal region. These findings suggested that these conserved domains were species-specific and related to the subunit types of AGPase proteins. The study may enable research on the AGPase-related specific characteristics of sweetpotatoes that do not exist in the other two species, such as starch metabolism and tuberization mechanism.

Emerging Targets for Systemic Treatment of Gastric Cancer: HER2 and Beyond

  • In-Ho Kim
    • Journal of Gastric Cancer
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    • 제24권1호
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    • pp.29-56
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    • 2024
  • In recent years, remarkable progress has been made in the molecular profiling of gastric cancer. This progress has led to the development of various molecular classifications to uncover subtype-specific dependencies that can be targeted for therapeutic interventions. Human epidermal growth factor receptor 2 (HER2) is a crucial biomarker for advanced gastric cancer. The recent promising results of novel approaches, including combination therapies or newer potent agents such as antibody-drug conjugates, have once again brought attention to anti-HER2 targeted treatments. In HER2-negative diseases, the combination of cytotoxic chemotherapy and programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) inhibitors has become the established standard of care in first-line settings. In the context of gastric cancer, potential biomarkers such as PD-L1 expression, Epstein-Barr virus, microsatellite instability, and tumor mutational burden are being considered for immunotherapy. Recently, promising results have been reported in studies on anti-Claudin18.2 and fibroblast growth factor receptor 2 treatments. Currently, many ongoing trials are aimed at identifying potential targets using novel approaches. Further investigations will be conducted to enhance the progress of these therapies, addressing challenges such as primary and acquired resistance, tumor heterogeneity, and clonal evolution. We believe that these efforts will improve patient prognoses. Herein, we discuss the current evidence of potential targets for systemic treatment, clinical considerations, and future perspectives.