• 제목/요약/키워드: evolutionary origin

검색결과 52건 처리시간 0.023초

Biological roles and an evolutionary sketch of the GRF-GIF transcriptional complex in plants

  • Kim, Jeong Hoe
    • BMB Reports
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    • 제52권4호
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    • pp.227-238
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    • 2019
  • GROWTH-REGULATING FACTORs (GRFs) are sequence-specific DNA-binding transcription factors that regulate various aspects of plant growth and development. GRF proteins interact with a transcription cofactor, GRF-INTERACTING FACTOR (GIF), to form a functional transcriptional complex. For its activities, the GRF-GIF duo requires the SWITCH2/SUCROSE NONFERMENTING2 chromatin remodeling complex. One of the most conspicuous roles of the duo is conferring the meristematic potential on the proliferative and formative cells during organogenesis. GRF expression is post-transcriptionally down-regulated by microRNA396 (miR396), thus constructing the GRF-GIF-miR396 module and fine-tuning the duo's action. Since the last comprehensive review articles were published over three years ago, many studies have added further insight into its action and elucidated new biological roles. The current review highlights recent advances in our understanding of how the GRF-GIF-miR396 module regulates plant growth and development. In addition, I revise the previous view on the evolutionary origin of the GRF gene family.

Complete mitochondrial genome sequence of Tosa-Jidori sheds light on the origin and evolution of Japanese native chickens

  • Osman, Sayed A.M.;Nishibori, Masahide;Yonezawa, Takahiro
    • Animal Bioscience
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    • 제34권6호
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    • pp.941-948
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    • 2021
  • Objective: In Japan, approximately 50 breeds of indigenous domestic chicken, called Japanese native chickens (JNCs), have been developed. JNCs gradually became established based on three major original groups, "Jidori", "Shoukoku", and "Shamo". Tosa-Jidori is a breed of Jidori, and archival records as well as its morphologically primitive characters suggest an ancient origin. Although Jidori is thought to have been introduced from East Asia, a previous study based on mitochondrial D-loop sequences demonstrated that Tosa-Jidori belongs to haplogroup D, which is abundant in Southeast Asia but rare in other regions, and a Southeast Asian origin for Tosa-Jidori was therefore suggested. The relatively small size of the D-loop region offers limited resolution in comparison with mitogenome phylogeny. This study was conducted to determine the phylogenetic position of the Tosa-Jidori breed based on complete mitochondrial D-loop and mitogenome sequences, and to clarify its evolutionary relationships, possible maternal origin and routes of introduction into Japan. Methods: Maximum likelihood and parsimony trees were based on 133 chickens and consisted of 86 mitogenome sequences as well as 47 D-loop sequences. Results: This is the first report of the complete mitogenome not only for the Tosa-Jidori breed, but also for a member of one of the three major original groups of JNCs. Our phylogenetic analysis based on D-loop and mitogenome sequences suggests that Tosa-Jidori individuals characterized in this study belong to the haplogroup D as well as the sub-haplogroup E1. Conclusion: The sub-haplogroup E1 is relatively common in East Asia, and so although the Southeast Asian origin hypothesis cannot be rejected, East Asia is another possible origin of Tosa-Jidori. This study highlights the complicated origin and breeding history of Tosa-Jidori and other JNC breeds.

현생 기저 피자식물에 대한 끝나지 않는 논쟁 (Endless debates on the extant basal-most angiosperm)

  • 김상태
    • 식물분류학회지
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    • 제40권1호
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    • pp.1-15
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    • 2010
  • 한 분류군의 진화의 역사를 파악하기 위해서는 분류군 내에서 가장 먼저 분지한 군(기저군)을 알아내는 것이 중요하다. 피자식물의 계통과 진화를 이해하고자 많은 식물학자들은 형태적 연구와 화석적 증거에 의해 현존하는 피자식물들 중 가장 먼저 분지하여 다른 모든 피자식물들과 자매군을 형성하는 분류군을 파악하려고 노력해 왔다. 최근 분자계통학의 기술적 발달과 자료의 축적으로 현생 기저 피자식물군에 대한 객관적 증거들이 제시되고 있다. 여전히 논쟁의 여지는 있지만, 대부분의 식물계통학자들은 1) 다수의 유전자들의 계통분석적 접근, 2) 복제된 두 유전자군의 계통수 네트웍 형성법, 3) 유전자의 구조적 접근 등의 분자적 증거에 의해 현생 기저 피자식물이 뉴칼레도니아에 자생하는 1과 1속 1종 식물인 Amborella trichopoda Baill.임에 동의하고 있다. 그러나 또 다른 가능성으로 Nymphaeaceae (수련과)와 A. trichopoda가 하나의 분계조를 형성하고 형성된 분계조가 다른 모든 피자식물의 자매군임을 지지하는 증거들도 일부 제시되어 현생 기저 피자식물에 대한 논쟁은 계속되고 있다. 현대 분자생물학적인 신기술의 발달은 대량의 분자적 자료를 제공하고 있어 이들 논쟁 해결의 실마리를 제공해 주고 있고, 진화적 모델식물로서의 Amborella 전체 유전체의 염기서열 결정과 이에 대한 파생연구는 Darwin이 지독하게 풀리지 않는 미스터리라 표현한 피자식물의 기원과 분화에 대한 해답을 제시해 줄 수 있을 것으로 기대된다.

In vitro Constructive Approaches to the Origin of Coding Sequences

  • Shiba, Kiyotaka
    • BMB Reports
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    • 제31권3호
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    • pp.209-220
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    • 1998
  • How did nature create the first set of genes at the beginning of life on Earth? One of the goals of molecular biology is to elucidate the fundamental rules governing how genes and, therefore, proteins were created. Through experiments carried out in the emerging field of "in vitro" or "benchtop" evolution studies, we are gaining new insights into the origins of genes and proteins as well as the origins of their functions (e.g., catalysis). In this review, I present an overview of recent experimental approaches to the question of the origin and evolution of genes. In addition, I will introduce a novel in vitro protein emergence system that was recently developed in my laboratory.

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On the Origin of the Correlation between Hubble Residual and Mass of the Type Ia Supernova Host Galaxies

  • Kang, Yijung;Kim, Young-Lo;Lim, Dongwook;Chung, Chul;Lee, Young-Wook
    • 천문학회보
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    • 제39권1호
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    • pp.36.1-36.1
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    • 2014
  • The correlation between mass of Type Ia Supernova (SN Ia) host galaxies and Hubble residual is now well-established. The origin of this relation, however, is yet to be understood. We have used low-resolution spectra of early-type hosts from YONSEI (YOnsei Nearby Supernovae Evolution Investigation) project to measure central velocity dispersion and Lick/IDS absorption indices. By using the Evolutionary Population Synthesis (EPS) models, luminosity-weighted mean age and metallicity of host galaxies were determined from $H{\beta}$ and absorption lines. Here we will discuss the correlation between the velocity dispersion, which indicates the mass of galaxies, and mean age of stellar population in our sample of early-type host galaxies.

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학교에서 진화론과 함께 지적설계론도 가르쳐야 하는가 (Do We Have to Teach Intelligent Design along with Evolution in Public Schools?)

  • 송광한
    • 한국융합학회논문지
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    • 제9권8호
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    • pp.185-198
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    • 2018
  • 본 논문은 학교에서 진화론과 함께 지적 설계론도 가르쳐야 한다는 요구가 강해지고 있는 상황에서 그에 대한 판단의 이론적 기초 자료로 활용하기 위한 목적으로 쓰였다. 진화론과 달리 경험적 증거가 거의 없는 지적 설계론이 과학이론이 될 가능성을 검증하기 위해 문헌들을 통해 지능이 무엇인지 밝히고, 그 지능의 흔적이 실제 자연 속에서 발견되고 있는지를 확인해 보았다. 자연에서 지능의 흔적인 '지적 요소'가 경험적으로 발견되면 지적 설계론도 과학이론으로서 인정받게 되어 진화론과 함께 학교 교육의 대상이 될 수 있지만 그렇지 않다면 논쟁할 가치조차 없어지게 된다. 지금까지 지능에 대한 문헌들을 종합한 결과 지능의 정체와 그 흔적을 찾을 수 있었으며, 그 흔적이 사고, 지식, 문명 등 인간으로부터 비롯된 다양한 인위적 산물에서 뿐만 아니라 자연의 모든 현상에서도 발견되고 있음이 확인되었다. 이런 결과를 바탕으로 본 논문은 진화론과 지적 설계론 간의 첨예한 대립과 갈등의 문제를 해결할 방법과 함께 진화론과 지적 설계론이 학교교육의 현장에서 어떻게 다루어져야 되는지에 대한 논의를 제공하고 있다.

Occurrence and Evolutionary Analysis of Coat Protein Gene Sequences of Iranian Isolates of Sugarcane mosaic virus

  • Moradi, Zohreh;Nazifi, Ehsan;Mehrvar, Mohsen
    • The Plant Pathology Journal
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    • 제33권3호
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    • pp.296-306
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    • 2017
  • Sugarcane mosaic virus (SCMV) is one of the most damaging viruses infecting sugarcane, maize and some other graminaceous species around the world. To investigate the genetic diversity of SCMV in Iran, the coat protein (CP) gene sequences of 23 SCMV isolates from different hosts were determined. The nucleotide sequence identity among Iranian isolates was more than 96%. They shared nucleotide identities of 75.5-99.9% with those of other SCMV isolates available in GenBank, the highest with the Egyptian isolate EGY7-1 (97.5-99.9%). The results of phylogenetic analysis suggested five divergent evolutionary lineages that did not completely reflect the geographical origin or host plant of the isolates. Population genetic analysis revealed greater between-group than within-group evolutionary divergence values, further supporting the results of the phylogenetic analysis. Our results indicated that natural selection might have contributed to the evolution of isolates belonging to the five identified SCMV groups, with infrequent genetic exchanges occurring between them. Phylogenetic analyses and the estimation of genetic distance indicated that Iranian isolates have low genetic diversity. No recombination was found in the CP cistron of Iranian isolates and the CP gene was under negative selection. These findings provide a comprehensive analysis of the population structure and driving forces for the evolution of SCMV with implications for global exchange of sugarcane germplasm. Gene flow, selection and somehow homologous recombination were found to be the important evolutionary factors shaping the genetic structure of SCMV populations.

Evolutionary history of the monospecific Compsopogon genus (Compsopogonales, Rhodophyta)

  • Nan, Fangru;Feng, Jia;Lv, Junping;Liu, Qi;Xie, Shulian
    • ALGAE
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    • 제31권4호
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    • pp.303-315
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    • 2016
  • Compsopogon specimens collected in China were examined based on morphology and DNA sequences. Five molecular markers from different genome compartments including rbcL, COI, 18S rDNA, psbA, and UPA were identified and used to construct a phylogenetic relationship. Phylogenetic analyses indicated that two different morphological types from China clustered into an independent clade with Compsopogon specimens when compared to other global samples. The Compsopogon clade exhibited robust support values, revealing the affiliation of the samples to Compsopogon caeruleus. Although the samples were distributed in a close geographical area, unexpected sequence divergences between the Chinese samples implied that they were introduced by different dispersal events and from varied origins. It was speculated that Compsopogon originated in North America, a portion of the Laurentia landmass situated in the Rodinia supercontinent at approximately 573.89-1,701.50 million years ago during the Proterozoic era.Although Compsopogonhad evolved for a rather long time, genetic conservation had limited its variability and rate of evolution, resulting in the current monospecific global distribution. Additional global specimens and sequence information were required to increase our understanding of the evolutionary history of this ancient red algal lineage.

Functional Haplotypes and Evolutionary Analyses of SBE1 in Collected Rice Germplasm

  • Thant Zin Maung;Yong-Jin Park
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2022년도 추계학술대회
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    • pp.216-216
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    • 2022
  • The starch-branching enzymes (BEs) are responsible for synthesizing the amylopectin, which plays an important role in determining the structural and physical properties of starch granules. BE has two differently functioning isoforms (BEI and BEIIa/b) based on their difference in the chain-length pattern by the degree of polymerization (DP), which mainly contributes to the amylopectin chain length distribution in starch biosynthesis. In this study, we investigated functional haplotypes and evolutionary analyses of SBE1 in 374 rice accessions (320 Korean bred and 54 wild). The analyses were performed based on the classified subpopulations. Haplotype analysis generates a total of 8 haplotypes, of which only four haplotypes were functional carrying four functional SNPs in four different exons of SBE1 on chromosome 6. Nucleotide diversity analysis showed a highest pi-value in aromatic group (0.0029), while the lowest diversity value was in temperate japonica (0.0002), indicating the signal of this gene evolution origin. Different directional selections could be estimated by negative Tajima's D value of temperate japonica (-1.1285) and positive Tajima's D value of tropical japonica (0.9456), where the selective sweeps were undergone by both positive purifying and balancing selections. Phylogenetic analysis indicates a closer relationship of the wild with most of the cultivated subgroups indicating a common ancestor for SBE1 gene. FST-values indicate distant genetic relationships of temperate japonica from all other classified groups. PCA and population structure analysis show an admixed structure of wild and cultivated subpopulations in some proportions.

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A pilot study on the formation and evolution of the Intracluster light: Preliminary results of the Coma cluster

  • Yoo, Jaewon;Ko, Jongwan
    • 천문학회보
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    • 제42권1호
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    • pp.52.1-52.1
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    • 2017
  • Galaxy clusters are the most massive gravitationally bound systems and thus probably the most recent objects to form. One of promising routes to understand the assembly history of galaxy clusters is to measure observable quantities of components in clusters that are sensitive to the evolutionary state of the cluster. Recent deep observations on the nearby clusters show distinct diffuse intracluster light (ICL), that the light from stars are not bound any individual cluster galaxy, however until now this component has not been well studied due to its faint nature, with typical brightness of ~100 times fainter than the sky background. As shown in galaxy cluster simulation studies, the ICL abundance increases during various dynamical exchanges of galaxies such as the disruption of dwarf galaxies, major mergers between galaxies and the tidal stripping of galaxies. Thus, the ICL is an effective tool to measure the evolutionary stage of galaxy clusters. Moreover, the investigation of the ICL evolution mechanism will allow us understand the galaxy evolution process therein. In this pilot study, we target the Coma cluster, where the existing ICL studies are limited only in the central region. With large and uniform deep optical images from the Subaru telescope, available only recently (Okabe et al. 2014), we are developing a robust ICL measurement technique, extracting the ICL surface brightness and color profiles, which will allow us to study the origin of the ICL and its connection to the evolutionary history of the Coma cluster. For the next phase, we plan to utilize the plenty of spectroscopy data from the MMT telescope to compare ICL properties with the star formation history of the brightest cluster galaxies (BCG), and discuss the ICL formation mechanism of the Coma cluster by comparing the distribution of cluster galaxies with the distribution of diffuse light inside the Coma cluster.

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