• Title/Summary/Keyword: Molecular evolution

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Taxonomic Revision of Notohymena gangwonensis (Protozoa: Ciliophora), with Notes on Its Cortical Granules and Scanning Electron Micrographs

  • Moon, Ji Hye;Kim, Kang-San;Chae, Kyu Seok;Min, Gi-Sik;Jung, Jae-Ho
    • Animal Systematics, Evolution and Diversity
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    • v.36 no.2
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    • pp.113-122
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    • 2020
  • From a moss sample, we isolated and identified Notohymena gangwonensis Kim et al., 2019 based on morphological and molecular data. The moss and type population has completely identical 18S rRNA (nuclear small subunit ribosomal RNA) gene sequences and both are highly similar in morphological and morphometric attributes, except for the diameter and arrangement of the cortical granules. Thus, we reexamined the type materials(i.e., micrographs and gDNA) and resulted in finding mistakes made by the authors of the species. Based on these data and supporting materials newly obtained (i.e., internal transcribed spacer [ITS] 1, ITS2, 5.8S, and partial 28S rDNA sequences, and scanning electron micrographs), we provide improved diagnosis of the species to clarify its identity. In addition, a key for Notohymena species is provided.

Biotoxins for Cancer Therapy

  • Liu, Cui-Cui;Yang, Hao;Zhang, Ling-Ling;Zhang, Qian;Chen, Bo;Wang, Yi
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.12
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    • pp.4753-4758
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    • 2014
  • In recent times, a number of studies have provided evidence that biotoxins present great potential as antitumor agents, such as snake venom, bee venom, some bacteria toxins and plant toxins, and thus could be used as chemotherapeutic agents against tumors. The biodiversity of venoms and toxins make them a unique source from which novel anticancer agent may be developed. Biotoxins, also known as natural toxins, include toxic substances produced by plants, animals and microorganisms. Here, we systematically list representative biological toxins that have antitumor properties, involving animal toxins, plant toxins, mycotoxins as well as bacterial toxins. In this review, we summarize the current knowledge involving biotoxins and the active compounds that have anti-cancer activity to induce cytotoxic, antitumor, immunomodulatory, and apoptotic effects in different tumor cells in vivo or in vitro. We also show insights into the molecular and functional evolution of biotoxins.

Secondary Structure and Phylogenetic Implications of ITS2 in the Genus Tricholoma

  • Suh, Seok-Jong;Kim, Jong-Guk
    • Journal of Microbiology and Biotechnology
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    • v.12 no.1
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    • pp.130-136
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    • 2002
  • The internal transcribed spacer (ITS) region in the genus Tricholoma was analyzed, including for its primary nucleotide sequence and secondary structural characterization. The secondary structures of the ITS2 region in the genus Tricholoma were identified for use in bioinformatic processes to study molecular evolution and compare secondary structures. Ten newly sequenced ITS regions were added to the analysis and submitted to the GenBank database. The resulting structure from a minimum energy algorithm indicated the four-domain model, as previously suggested by others. The conserved secondary structure of the ITS2 sequences of the genus Tricholoma exhibited certain unique features, including pyrimidine tracts in the loops of domain A and a complete structure containing four domains, with motifs identified in other ITS2 secondary structures. A phylogenetic tree was derived from sequence alignment based on the secondary structures. From the resulting maximum parsimonious tree, it was found that the species in the genus Tricholoma had evolved monophyletically and were composed of four groups, as supported by the bootstrapping values and pileus color.

First Record of Potentially Pathogenic Amoeba Vermamoeba vermiformis (Lobosea: Gymnamoebia) Isolated from a Freshwater of Dokdo Island in the East Sea, Korea

  • Park, Jong Soo
    • Animal Systematics, Evolution and Diversity
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    • v.32 no.1
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    • pp.1-8
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    • 2016
  • Vermamoeba vermiformis is a very important free-living amoeba for human health in association with Legionnaires' disease and keratitis. This interesting amoeba was firstly isolated from a freshwater of Dokdo (island), which was historically used for drinking water. Trophozoites and cyst forms of V. vermiformis strain MG1 are very similar to previous reported species. Trophozoites of V. vermiformis strain MG1 showed cylindrical shape with prominent anterior hyaline region. The average ratio of length and width was about 6.5. Typically, cysts of the strain MG1 showed a spherical or slightly ovoidal shape with smooth wall, and lacked cyst pores. Some cysts had crenulate-walled ectocyst, which was separated from endocyst wall. Further, 18S rRNA gene sequence of V. vermiformis strain MG1 showed very high similarity to other V. vermiformis species (99.4%-99.9% identity). Molecular phylogenetic analysis based on 18S rRNA gene sequences clearly confirmed that the isolate was one strain of V. vermiformis with maximum bootstrap value (maximum likelihood: 100%) and Bayesian posterior probability of 1. Thus, the freshwater of Dokdo in Korea could harbor potentially pathogenic amoeba that may cause diseases in humans.

Genetic Distinctness of the Korean Red-backed Vole (Myodes regulus) from Korea, Revealed by the Mitochondrial DNA Control Region

  • Koh, Hung-Sun;Yang, Beong-Kug;Lee, Bae-Keun;Jang, Kyung-Hee;Bazarsad, Davaa;Park, Nam-Jeong
    • Animal Systematics, Evolution and Diversity
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    • v.26 no.3
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    • pp.183-186
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    • 2010
  • To identify Korean red-backed voles (Myodes regulus) from Korea by mitochondrial DNA (mtDNA) sequencing, we obtained mtDNA control region sequences of 17 red-backed voles from Korea and northeast China, and these sequences were compared with the corresponding haplotypes of Myodes obtained from GenBank. We identified five red-backed voles from Mt. Changbai and Harbin as M. rufocanus and another three redbacked voles from Harbin as M. rutilus, respectively. Moreover, nine red-backed voles from Korea, showing the average nucleotide distance of 0.66% among nine haplotypes, were different from other species of Myodes, and the average distance between nine haplotypes of red-backed voles from Korea and seven haplotypes of M. rufocanus was 6.41%, whereas the average distance between nine haplotypes of red-backed voles from Korea and five haplotypes of M. rutilus was 14.8%. We identified the red-backed voles from Korea as M. regulus, and found that M. regulus is distinct in its mtDNA control region sequences as well, although we propose further analyses with additional specimens from East Asia using nuclear and mtDNA markers to confirm the distinctness of M. regulus.

Nucleotide Polymorphism of Green-like Visual Pigment Gene from Eyed and Blind Forms of the Mexican Tetra, Astyanax fasciatus (Mexican tetra (Astyanax fasciatus)의 녹색 시간 색소포 유전자의 염기서열 다형화 현상)

  • 송춘복;쑈죠요코야마
    • Journal of Aquaculture
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    • v.11 no.3
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    • pp.295-301
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    • 1998
  • Since the end of the Pliocene, ancestral strains of Astyanax fasciatus have been accidently washed into different caves at the time of flooding and have lost their eyes and body pigments. Availability of this independently derived cave fish and their ancestral form within a single species provided a unique opportunity for studying the process of molecular evolution of the visual pigment gene. The nucleotide sequence comparisons of an ancestral river fish and two cave fish showed that nucleotide polymorphism of a green-like visual pigment gene between the eyed and blind form of A. fasciatus was much higher than that between the same blind form. Considering the number of nucleotide substitutions per nucleotide site and the direction of the nucleotide substitutions, more nucleotide substituions between the different forms of fish rater than the same one were probably due to more frequent mutations in the eyed river form. Nucleotide substitutions per site at the intron have been ocurred more than three times faster than those at the exon. This result indicates that the functional constraint has affected the green-like visual pigment gene of the blind cave fish although its eye sight is no longer required.

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Molecular fingerprinting of olive flounder pathogenic Streptococcus parauberis strains by random amplified polymorphic DNA analysis

  • Jung, Yong-Uk;Kang, Sang-Hyuck;Jin, Chang-Nam;Kang, Bong-Jo;Heo, Moon-Soo
    • 한국생물공학회:학술대회논문집
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    • 2005.10a
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    • pp.899-903
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    • 2005
  • Two infectious species of Streptococcosis pathogens were detected by multiplex PCR assay. Detection rates of Streptococcus iniae and S. parauberis could reach 44.9% and 55.1% respectively for one year during 2004 to 2005 in Jeju island. These findings showed that S. parauberis strains were important pathogen with streptococcosis of olive flounder in Jeju island. These findings showed that S. parauberis strains were important pathogen with streptococcosis of olive flounder in Jeiu island. In the present study we have investigated the interspecific relationship of all Jeju area of S. parauberis by RAPD analysis. Represent strains divided to four groups by RAPD fingerprints. The important differences observed between the olive flounder isolates suggest that they could constitute a well-differentiated group or a separate clonal line within this bacterial species. Though, serological research of S. parauberis strains in Jeju island not exist yet. These strains doing the serological evolution.

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Differentially Expressed Genes under Cold Acclimation in Physcomitrella patens

  • Sun, Ming-Ming;Li, Lin-Hui;Xie, Hua;Ma, Rong-Cai;He, Yi-Kun
    • BMB Reports
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    • v.40 no.6
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    • pp.986-1001
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    • 2007
  • Cold acclimation improves freezing tolerance in plants. In higher plants, many advances have been made toward identifying the signaling and regulatory pathways that direct the low-temperature stress response; however, similar insights have not yet been gained for simple nonvascular plants, such as bryophytes. To elucidate the pathways that regulate cold acclimation in bryophytes, we used two PCR-based differential screening techniques, cDNA amplified fragment length polymorphism (cDNA-AFLP) and suppression subtractive hybridization (SSH), to isolate 510 ESTs that are differentially expressed during cold acclimation in Physcomitrella patens. We used realtime RT-PCR to further analyze expression of 29 of these transcripts during cold acclimation. Our results show that cold acclimation in the bryophyte Physcomitrella patens is not only largely similar to higher plants but also displays distinct differences, suggests significant alteration during the evolution of land plants.

Helper virus-free gutless adenovirus (HF-GLAd): a new platform for gene therapy

  • Liu, Jida;Seol, Dai-Wu
    • BMB Reports
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    • v.53 no.11
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    • pp.565-575
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    • 2020
  • Gene therapy is emerging as a treatment option for inherited genetic diseases. The success of this treatment approach greatly depends upon gene delivery vectors. Researchers have attempted to harness the potential of viral vectors for gene therapy applications over many decades. Among the viral vectors available, gutless adenovirus (GLAd) has been recognized as one of the most promising vectors for in vivo gene delivery. GLAd is constructed by deleting all the viral genes from an adenovirus. Owing to this structural feature, the production of GLAd requires a helper that supplies viral proteins in trans. Conventionally, the helper is an adenovirus. Although the helper adenovirus efficiently provides helper functions, it remains as an unavoidable contaminant and also generates replication-competent adenovirus (RCA) during the production of GLAd. These two undesirable contaminants have raised safety concerns and hindered the clinical applications of GLAd. Recently, we developed helper virus-free gutless adenovirus (HF-GLAd), a new version of GLAd, which is produced by a helper plasmid instead of a helper adenovirus. Utilization of this helper plasmid eliminated the helper adenovirus and RCA contamination in the production of GLAd. HF-GLAd, devoid of helper adenovirus and RCA contaminants, will facilitate its clinical applications. In this review, we discuss the characteristics of adenoviruses, the evolution and production of adenoviral vectors, and the unique features of HF-GLAd as a new platform for gene therapy. Furthermore, we highlight the potential applications of HF-GLAd as a gene delivery vector for the treatment of various inherited genetic diseases.

New role of LTR-retrotransposons for emergence and expansion of disease-resistance genes and high-copy gene families in plants

  • Kim, Seungill;Choi, Doil
    • BMB Reports
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    • v.51 no.2
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    • pp.55-56
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    • 2018
  • Long terminal repeat retrotransposons (LTR-Rs) are major elements creating new genome structure for expansion of plant genomes. However, in addition to the genome expansion, the role of LTR-Rs has been unexplored. In this study, we constructed new reference genome sequences of two pepper species (Capsicum baccatum and C. chinense), and updated the reference genome of C. annuum. We focused on the study for speciation of Capsicum spp. and its driving forces. We found that chromosomal translocation, unequal amplification of LTR-Rs, and recent gene duplications in the pepper genomes as major evolutionary forces for diversification of Capsicum spp. Specifically, our analyses revealed that the nucleotide-binding and leucine-rich-repeat proteins (NLRs) were massively created by LTR-R-driven retroduplication. These retoduplicated NLRs were abundant in higher plants, and most of them were lineage-specific. The retroduplication was a main process for creation of functional disease-resistance genes in Solanaceae plants. In addition, 4-10% of whole genes including highly amplified families such as MADS-box and cytochrome P450 emerged by the retroduplication in the plants. Our study provides new insight into creation of disease-resistance genes and high-copy number gene families by retroduplication in plants.