• Parasites, Hosts and Diseases
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• 제59권1호
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• pp.67-76
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• 2021

Legionella pneumophila is an opportunistic pathogen that survives and proliferates within protists such as Acanthamoeba spp. in environment. However, intracellular pathogenic endosymbiosis and its implications within Acanthamoeba spp. remain poorly understood. In this study, RNA sequencing analysis was used to investigate transcriptional changes in A. castellanii in response to L. pneumophila infection. Based on RNA sequencing data, we identified 1,211 upregulated genes and 1,131 downregulated genes in A. castellanii infected with L. pneumophila for 12 hr. After 24 hr, 1,321 upregulated genes and 1,379 downregulated genes were identified. Gene ontology (GO) analysis revealed that L. pneumophila endosymbiosis enhanced hydrolase activity, catalytic activity, and DNA binding while reducing oxidoreductase activity in the molecular function (MF) domain. In particular, multiple genes associated with the GO term 'integral component of membrane' were downregulated during endosymbiosis. The endosymbiont also induced differential expression of various methyltransferases and acetyltransferases in A. castellanii. Findings herein are may significantly contribute to understanding endosymbiosis of L. pneumophila within A. castellanii.

• Molecules and Cells
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• 제41권3호
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• pp.161-167
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• 2018

Chloroplasts are present in organisms belonging to the kingdom Plantae. These organelles are thought to have originated from photosynthetic cyanobacteria through endosymbiosis. During endosymbiosis, most cyanobacterial genes were transferred to the host nucleus. Therefore, most chloroplast proteins became encoded in the nuclear genome and must return to the chloroplast after translation. The N-terminal cleavable transit peptide (TP) is necessary and sufficient for the import of nucleus-encoded interior chloroplast proteins. Over the past decade, extensive research on the TP has revealed many important characteristic features of TPs. These studies have also shed light on the question of how the many diverse TPs could have evolved to target specific proteins to the chloroplast. In this review, we summarize the characteristic features of TPs. We also highlight recent advances in our understanding of TP evolution and provide future perspectives about this important research area.

• Animal cells and systems
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• 제5권4호
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• pp.291-297
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• 2001

Three species of endosymbiotic dinoflagellates, zooxanthellae, are investigated from six host species of anthozoans from Korea. Three unrecorded endosymbionts species are Symbiodinium kawagutii, Symbiodinium microadriaticum, and Symbiodinium sp. Symbiodinium kawagutii Is associated with Alveopora japonica, Anthopleura japonica and Parasicyonis actinostoloides. Symbiodinium microadiraticum is found in Anthopleura kurogane and Parasicyonis sp. Unlike the former two symbionts, Symbiodinium sp. is associated with Anthopleura midori.

• 한국동물학회지
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• 제22권2호
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• pp.67-81
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• 1979

Chloramphenicol 용액으로 배양한 amebae의 endosymbiotes를 전현적 세포화학법으로 연구하였다. 대조군에 있어서 acid phosphatase 활성은 오르구 최근에 섭취한 Tetrahymena 주위의 식포내에만 관찰되었으나 chloramphenicol로 처리한 실험군에서는 항균제로 변성된 endosymbiotes를 함유한 vacuoles내에도 다량의 acid phosphatase 활성이 관찰되었다. 이는 endosymbiotes가 chloramphenicol에 의한 정균작용으로 인하여 숙주의 세포내소화작용을 저지하는 힘을 소실한데 기인한다고 사료된다.

• Journal of Species Research
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• 제10권2호
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• pp.142-153
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• 2021

Algal genomics approaches provide a massive number of genome/transcriptome sequences and reveal the evolutionary history vis-à-vis primary and serial endosymbiosis events that contributed to the biodiversity of photosynthetic eukaryotes in the eukaryote tree of life. In particular, phylogenomic methods using several hundred or thousands of genes have provided new insights into algal taxonomy and systematics. Using this method, many novel insights into algal species diversity and systematics occurred, leading to taxonomic revisions. In addition, horizontal gene transfers (HGTs) of functional genes have been identified in algal genomes that played essential roles in environmental adaptation and genomic diversification. Finally, algal genomics data can be used to address the pangenome, including core genes shared among all isolates and partially shared strain-specific genes. However, some aspects of the pangenome concept (genome variability of intraspecies level) conflict with population genomics concepts, and the issue is closely related to defining species boundaries using genome variability. This review suggests a desirable future direction to merge algal pangenomics and population genomics beyond traditional molecular phylogeny and taxonomy.

• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.119-136
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• 2000

Being autotrophic, algae occupy a trategic place in the biosphere. They produce oxygen both directly and indirectly through the chloroplasts of all green plants. The chloroplasts are believed to have originated from archaic prokaryotic algae through endosymbiosis with primitive eukaryotic cells. Phytoplankton and other algae regulate the global environment not only by releasing oxygen but also by fixing carbon dioxide. They affect water quality, help in the treatment of sewage, and produce biomass. They can be used to produce hydrogen which is a clean fuel, and biodiesel, and fix $N_2$ for use as a biofertilizer. Some other services of algae to the environment include restoration of metal damaged ecosystems, reducing the atmospheric $CO_2$ load and citigating global warming, reclamation of saline-alkaline unfertile lands, and production of dimethyl sulphide (DMS) and oxides of nitrogen (NOx) involved in the regulation of UV radiation. ozone concentration, and global warming. Algae can be valuable in understanding and resolving certain environmental issues.

• ALGAE
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• 제21권1호
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• pp.1-10
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• 2006

Genomic data is accumulating in public database at an unprecedented rate. Although presently dominated by the sequences of metazoan, plant, parasitic, and picoeukaryotic taxa, both expressed sequence tag (EST) and complete genomes of free-living algae are also slowly appearing. This wealth of information offers the opportunity to clarify many long-standing issues in algal and plant evolution such as the contribution of the plastid endosymbiont to nuclear genome evolution using the tools of comparative genomics and multi-gene phylogenetics. A particularly powerful approach for the automated analysis of genome data from multiple taxa is termed phylogenomics. Phylogenomics is the convergence of genomics science (the study of the function and structure of genes and genomes) and molecular phylogenetics (the study of the hierarchical evolutionary relationships among organisms, their genes and genomes). The use of phylogenetics to drive comparative genome analyses has facilitated the reconstruction of the evolutionary history of genes, gene families, and organisms. Here we survey the available genome data, introduce phylogenomic pipelines, and review some initial results of phylogenomic analyses of algal genome data.

• Parasites, Hosts and Diseases
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• 제35권2호
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• pp.127-134
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• 1997

콘택트렌즈 보존 용기 유래 가시아메바 KA/LS주의 세포질 내에 존재하는 bacterial endosymbiont(내공생세균)를 투과전자현미경으로 관찰하여 확인하였다. 숙주인 가시아메바 KA/LS주는 형태학적으로 제2군에 속하였고 rDNA PCR-RFLP 결과 A. lugdunensis로 동정되었다. 미토콘드리아 DNA RFLP와 동위효소 분석상 이 충주는 국내 콘택트렌즈 보존용기에서 가장 흔히 분리되는 type인 KA/L1주, 국내 임상 분리주 중 하나인 KA/E2주, 내공생세균을 가지는 것으로 보고된 병원 냉각수 유래 KA/W4주 및 L3a주와 동일하거나 매우 유사한 성적을 보였다. 내 공생세균은 약 $1.38{\;}{\times}{\;}0.50{\;}{\mu\textrm{m}}$의 크기였고, 아메바 세포질 내에 불규칙하게 분포하고 있었으며 그 표면에 아메바의 ribosome이 부착되어 있었다. 내공생세균을 둘러싼 lacunae나 막과 같은 구조는 관찰되지 않았다. Legionoun 특이 primer를 이용한 효소중합반응(PCR)에서 내공생세균의 염색체 DNA는 증폭되지 않았다 A. lugdunensis의 우리말 이름을 담수가시아메바로 제안한다.

• ALGAE
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• 제32권4호
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• pp.359-377
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• 2017

Pyropia haitanensis (T. J. Chang et B. F. Zheng) N. Kikuchi et M. Miyata is one of the most commercially useful macroalgae cultivated in southeastern China. In red algae, the biosynthesis of terpenoids through 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway can produce a direct influence on the synthesis of many biologically important metabolites. In this study, two genes of cDNAs, 1-deoxy-D-xylulose-5-phosphate synthase (DXS) and 1-deoxy-D-xylulose-5-phosphate reductase (DXR), which encoding the first two rate-limiting enzymes among MEP pathway were cloned from P. haitanensis. The cDNAs of P. haitanensis DXS (PhDXS) and DXR (PhDXR) both contained complete open reading frames encoding polypeptides of 764 and 426 amino acids residues, separately. The expression analysis showed that PhDXS was significant differently expressed between leafy thallus and conchocelis as PhDXR been non-significant. Additionally, expression of PhDXR and its downstream gene geranylgeranyl diphosphate synthase were both inhibited by fosmidomycin significantly. Meanwhile, we constructed types of phylogenetic trees through different algae and higher plants DXS and DXR encoding amino acid sequences, as a result we found tree clustering consequences basically in line with the "Cavalier-Smith endosymbiotic theory." Whereupon, we speculated that in red algae, there existed only complete MEP pathway to meet needs of terpenoids synthesis for themselves; Terpenoids synthesis of red algae derivatives through mevalonate pathway came from two or more times endosymbiosis of heterotrophic eukaryotic parasitifer. This study demonstrated that PhDXS and PhDXR could play significant roles in terpenoids biosynthesis at molecular levels. Meanwhile, as nuclear genes among MEP pathway, PhDXS and PhDXR could provide a new way of thinking to research the problem of chromalveolata biological evolution.