• Molecules and Cells
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• 제27권3호
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• pp.365-381
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• 2009

The chloroplast DNA sequences of Megaleranthis saniculifolia, an endemic and monotypic endangered plant species, were completed in this study (GenBank FJ597983). The genome is 159,924 bp in length. It harbors a pair of IR regions consisting of 26,608 bp each. The lengths of the LSC and SSC regions are 88,326 bp and 18,382 bp, respectively. The structural organizations, gene and intron contents, gene orders, AT contents, codon usages, and transcription units of the Megaleranthis chloroplast genome are similar to those of typical land plant cp DNAs. However, the detailed features of Megaleranthis chloroplast genomes are substantially different from that of Ranunculus, which belongs to the same family, the Ranunculaceae. First, the Megaleranthis cp DNA was 4,797 bp longer than that of Ranunculus due to an expanded IR region into the SSC region and duplicated sequence elements in several spacer regions of the Megaleranthis cp genome. Second, the chloroplast genomes of Megaleranthis and Ranunculus evidence 5.6% sequence divergence in the coding regions, 8.9% sequence divergence in the intron regions, and 18.7% sequence divergence in the intergenic spacer regions, respectively. In both the coding and noncoding regions, average nucleotide substitution rates differed markedly, depending on the genome position. Our data strongly implicate the positional effects of the evolutionary modes of chloroplast genes. The genes evidencing higher levels of base substitutions also have higher incidences of indel mutations and low Ka/Ks ratios. A total of 54 simple sequence repeat loci were identified from the Megaleranthis cp genome. The existence of rich cp SSR loci in the Megaleranthis cp genome provides a rare opportunity to study the population genetic structures of this endangered species. Our phylogenetic trees based on the two independent markers, the nuclear ITS and chloroplast MatK sequences, strongly support the inclusion of the Megaleranthis to the Trollius. Therefore, our molecular trees support Ohwi's original treatment of Megaleranthis saniculifolia to Trollius chosenensis Ohwi.

• Journal of Plant Biotechnology
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• 제37권3호
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• pp.275-282
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• 2010

고등식물의 엽록체 형질전환은 핵 형질전환에서 기대 할 수 없는 여러 가지 이점을 가진다. 외래 단백질의 발현율을 획기적으로 높일 수 있고, 여러 유전자를 동시에 발현시킬 수 있으며, 상동재조합에 의한 부위-특이적 유전자 삽입으로 인해 유전자 침묵 및 위치효과가 없다. 더욱이, 대부분 작물은 화분을 통한 도입된 유전자의 전이가 불가능한 모계 유전을 하기 때문에 엽록체 형질전환은 환경 친화적이다. 엽록체 형질전환 시스템은 핵 형질 전환과 달리 작물에서의 성공에 제한적이었으나 지난 10년 동안 이런 한계가 극복되어 콩, 당근, 상추 및 유채 등의 작물에서도 성공하게 되었다. 그러므로 이제 작물의 엽록체 형질전환은 농업적 형질의 개선뿐 만 아니라, 고부가가치 백신과 의료용 단백질 생산을 통한 의약품 산업의 성장에 활용될 수 있을 것이다.

• Journal of Species Research
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• 제6권1호
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• pp.76-90
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• 2017

Aster altaicus var. uchiyamae Kitam. is an endemic taxon of Korea and is protected by law as an endanger taxon. The genetic information of A. altaicus var. uchiyamae is unavailable in Genbank. Here we sequenced chloroplast genome of A. altaicus var. uchiyamae. The cp-genome of Aster altaicus var. uchiyamae was 152,446 bps in size: LSC was 84,240 bps, IR 25,005 bps, SSC 18,196 bps. The cp-genome contains 112 genes and 21 introns consisted of 79 protein coding genes(PCGs), 4 RNA genes, and 29 tRNA genes, with 20 group II introns and one group I intron. There were three pseudo-genes including ${\psi}$-ycf1, ${\psi}$-rps19, and ${\psi}$-trnT_GGU. Eighteen genes, five introns, and parts of two genes and an intron are found within the IR, which has two copies. The cp-DNA of Aster altaicus var. uchiyamae is distinguished from A. spathulifolius, only known cp-genome of the genus Aster, by 172 SNP in genic regions of 43 PCGs and 21 indels in 11 PCGs and SSU. The chloroplast genome sequence was deposited at GenBank (KX35265).

• 미생물학회지
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• 제37권2호
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• pp.137-144
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• 2001

순천만 갯벌의 세균 군집의 다양성을 조사하기 위해 16S rDNA의 다양성을 조사하였다. 갯벌로부터 전체 핵산을 분리한 후, 세균에 상보적인 universal primer로 증폭된 16S rDNA로부터 클론 라이브러리를 만들었다. 총 111개의 클론으로부터 HaeIII를 이용하여 amplified rDNA restriction analysis (ARDRA)를 수행하고, Gelcompar II 프로그램을 이용하여 pattern을 clustering하였다. 111개의 클론 중 100가지의 서로 다른 RFLP type이 조사되었고, 이들 중 전체 클론 라이브러리를 대표할 수 있는 20개의 클론을 선별하여 부분적인 염기서열을 분석하여 세균 다양성을 분석하였다. 20개의 클론중에는 RDP와 GenBank에서 제공하는 small subunit RNA database와 동일한 클론은 존재하지 않았으며, 이미 알려진 배양 가능한 세균의 16S rRNA 염기서열과 비교 하였을때 77∼96.8%의 유사도를 보였다. 또한 이들 20개의 클론은 alpha-, delta-, gamma-Proteobacteria, low G+C Gram positive bacteria, high G+C Gram positive bacteria, Sphingobacteria (Cytophaga); Cyanobacteria (Chloroplast)등 주요한 7개 lineage에 속했으며, 클론들 중 Proteobacteria가 우점종을 차지하고 있었다.

• Journal of Plant Biotechnology
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• 제38권1호
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• pp.42-48
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• 2011

고등식물의 엽록체 유전공학은 핵 형질전환과 비교해 볼때 여러 가지 독특한 장점을 가진다. 높은 transgene 발현율, 상동 재조합에 의한 site-specific transgene의 삽입으로 인해 유전자의 position effect가 없으며, 단일 형질전환으로 동시에 여러 유전자의 도입이 가능하고 모계 유전으로 인해 화분 방출 위험을 감소시킬 수 있다. 담배 specific한 pCtVG (trnI-Prrn-aadA-mgfp-TpsbA-trnA) 벡터를 이용하여 안정적인 감자 엽록체 형질전환 시스템을 개발하였다. 감자 엽록체 게놈으로 외래유전자의 삽입과 homoplasmic level은 PCR과 Southern blot 분석으로 확인하였다. Northern과 immunoblot 분석 및 GFP fluorescence imaging을 통하여 엽록체 형질전환체의 잎에서 GFP 유전자가 강하게 발현, 축적됨을 알 수 있었다. 본 연구에서 확립된 감자 엽록체 형질전환 시스템을 이용하여 유용 유전자를 도입함으로써 농업적 형질을 개선하거나 고부가가치 단백질을 대량 생산하는 감자를 보다 효율적으로 개발할 수 있을 것이다.

• ALGAE
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• 제18권2호
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• pp.121-127
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• 2003

The pyrenoid ultrastructure and distribution of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and Rubisco activase in the chloroplasts of Chlamydomonas reinhardtii was studied using the immunogold localization technology with electron microscopy. There were several tubular thylakoids invading in the pyrenoid matrix to form several spokewise channels. The connections between pyrenoid matrix and stroma of chloroplast were the partial of channels. The starch sheath surrounding the pyrenoid was separated into several parts by the connections in transection. Some thylakoids were packed together near the connections in one side of the pyrenoid. Those special structures might be used to transport substance between pyrenoid and stroma of chloroplasts. With the antibody raised against the large subunits of Rubsico from C. protothecoides, the result of the gold immunolocalization of Rubisco in Chlamydomonas reinhardtii showed most of the gold particles heavily labeled the pyrenoid matrix, as well as the starch sheath matrix, and very few in the stroma of chloroplasts. The gold particle density was 880.00 $\pm$ 164.32, 190.00 $\pm$ 152.39 and 9.60 $\pm$ 5.37 ${\mu}m^{-2}$ in pyrenoid matrix, starch sheath and stroma region of chloroplast respectively (background: 5.67 $\pm$ 1.53 ${\mu}m^{-2}$). 99.59% of the total Rubiscos was calculated to be concentrated in the pyrenoid matrix and starch sheath by spatial densities. The gold immunolocalization of Rubisco activase also showed that Rubisco activase was mainly concentrated in the periphery of the pyrenoid and the starch sheath (the density was as high as 229.69 $\pm$ 96.96 ${\mu}m^{-2}$). There were very few gold particles located in the stroma of chloroplasts. These results indicated that pyrenoid surface and starch sheath was the site for Rubisco activation and $CO_2$ fixation, which supported the suggestion that pyrenoids perform photosynthesis function.

• ALGAE
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• 제34권2호
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• pp.71-90
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• 2019

A new encrusting red alga was found growing abundantly on glass debris items that drifted ashore along the coasts of Oregon and Washington. These included discarded fluorescent tubes, incandescent light bulbs, capped liquor bottles, and ball-shaped fishing-net floats. Field collections and unialgal cultures of the alga revealed that it consisted of two morphological phases: a young loosely aggregated turf and a mature consolidated mucilaginous crust. The turf phase consisted of a basal layer of globose cells that produced erect, rarely branched, uniseriate to multiseriate filaments up to $500{\mu}m$ long with closely spaced cells lacking pit-plugs. These filaments expanded in size from their bases to their tips and released single cells as spores. At maturity, a second phase of growth occurred that produced a consolidated crust, up to $370{\mu}m$ thick. It consisted of a basal layer of small, tightly appressed ellipsoidal-to-elongate cells that generated a mucilaginous perithallial matrix containing a second type of filament with irregularly spaced cells often undergoing binary division. At the matrix surface, the original filaments continued to grow and release spores but often also eroded. Individual cells, examined using confocal microscopy and SYBR Green staining, were found to contain a central nucleus, a single highly lobed peripheral chloroplast without a pyrenoid, and numerous chloroplast nucleoids. Morphological data from field and culture isolates and molecular data (rbcL, psbA, and SSU) show that this alga is a new genus and species which we name Viator vitreocola, "a traveller on glass."

• ALGAE
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• 제23권2호
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• pp.119-133
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• 2008

We cultured a tubular marine green alga, originally identified as Capsosiphon groenlandicus (J. Agardh) K.L. Vinogradova, from Amaknak Island, Alaska. The alga had an alternation of heteromorphic generations in which tubular monoecious fronds produced quadriflagellate zoospores and/or biflagellate isogametes. The gametes fused to produce cysts or Codiolum-like zygotes with long, tortuous stalks. Cysts and codiola produced 8-16 aplanospores, which germinated in situ to yield upright fronds. Fronds arising from both aplanospores and zoospores displayed a distinctive development in which non-septate colorless rhizoids from the base of the initially uniseriate, Ulothrix-like filament were transformed into septate uniseriate Ulothrix-like photosynthetic filaments. These transformed filaments then developed new basal non-septate rhizoids. This pattern of rhizoids becoming filaments, which then produced new rhizoids, was repeated to yield a tuft of up to 50 fronds. Periclinal and longitudinal divisions occurred in each filament, starting basally, until the mature tubular thallus was achieved. Pyrenoid ultrastructure revealed several short inward extensions of chloroplast lamellae, each of which was surrounded by pyrenoglobuli. Analysis of ribosomal SSU and ITS sequences placed this alga in the family Ulotrichaceae, order Ulotrichales, together with but as a distinct species from North Atlantic Capsosiphon groenlandicus. Analysis of a partial ITS sequence from authentic Capsosiphon fulvescens, the current name of the type of the genus Capsosiphon, indicated that neither our material nor C. groenlandicus belongs in that genus, and we propose a new genus, Pseudothrix, to accommodate both species. We propose P. borealis for the North Pacific entity formerly called C. groenlandicus and make the new combination P. groenlandica for the Atlantic species.

• ALGAE
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• 제39권2호
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• pp.97-108
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• 2024

The Ralfsiaceae family, part of the Ralfsiales order and consisting of crustose brown algae, includes five genera: Analipus, Endoplura, Fissipedicella, Heteroralfsia, and Ralfsia. In this study, a novel crustose genus named Ramipedicella gen. nov. is introduced within the Ralfsiaceae based on molecular and morphological analyses. Phylogenetic analyses using both concatenated dataset (rbcL + COI-5P genes) and rbcL indicate that the crustose brown algae that we collected from Korea and Russia form a unique grouping within the Ralfsiaceae. This grouping is strongly supported by both bootstrap analysis and Bayesian posterior probabilities. The genetic differences in the rbcL and COI-5P sequences between Ramipedicella and other genera within Ralfsiaceae range from 6.7 to 9.3% for rbcL and from 15.5 to 20.8% for COI-5P. Ramipedicella is characterized by crustose thalli having new crusts growing on top of old ones with a hypothallial basal layer and erect perithallial filaments, long cells with width-to-length ratio of 1 : 1-16, single chloroplast per cell, plurangia with one to several sterile cells, one to several unangia produced from unicellular stalks or from the lateral-basal region to the paraphyses, and unangia arising sequencially in irregularly branched specialized filaments. Ramipedicella, the recently identified genus, comprises two distinct species. Ramipedicella miniloba, the type species, is distinguished by crusts with small lobes, numerous hair tufts, plurangia terminated by 1-4 sterile cells, and large oblong unangia. Ramipedicella longicellularis is identified by generally smooth crusts, absence of phaeophycean hairs, plurangia terminated by 1-2 apical sterile cells, and smaller mostly oblanceolate unangia.

• ALGAE
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• 제21권4호
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• pp.407-416
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• 2006

Low molecular weight carbohydrates, phycobilin pigments and cell structure using light and transmission electron microscopy were used to describe a new genus of unicellular red algae, Erythrolobus coxiae (Porphyridiales, Porphyrideophyceae, Rhodophyta). The nucleus of Erythrolobus is located at the cell periphery and the pyrenoid, enclosed by a cytoplasmic starch sheath, is in the cell center. The pyrenoid matrix contains branched tubular thylakoids and four or more chloroplast lobes extend from the pyrenoid along the cell periphery. A peripheral encircling thylakoid is absent. The Golgi apparatus faces outward at the cell periphery and is always associated with a mitochondrion. Porphyridium and Flintiella, the other members of the Porphyrideophyceae, also lack a peripheral encircling thylakoid and have an ER-mitochondria-Golgi association. The low molecular weight carbohydrates digeneaside and floridoside are present, unlike both Porphyridium and Flintiella, which have only floridoside. The phycobilin pigments B-phycoerythrin, R-phycocyanin and allophycocyanin are present, similar to Porphyridium purpureum. The cells have a slow gliding motility without changing shape and do not require substrate contact. The ultrastructural features are unique to members of the Porphyrideophyceae and recent molecular analyses clearly establish the validity of this new red algal class and the genus Erythrolobus.