• Title/Summary/Keyword: Sequence divergence

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An Efficient Video Retrieval Algorithm Using Key Frame Matching for Video Content Management

  • Kim, Sang Hyun
    • International Journal of Contents
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    • v.12 no.1
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    • pp.1-5
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    • 2016
  • To manipulate large video contents, effective video indexing and retrieval are required. A large number of video indexing and retrieval algorithms have been presented for frame-wise user query or video content query whereas a relatively few video sequence matching algorithms have been proposed for video sequence query. In this paper, we propose an efficient algorithm that extracts key frames using color histograms and matches the video sequences using edge features. To effectively match video sequences with a low computational load, we make use of the key frames extracted by the cumulative measure and the distance between key frames, and compare two sets of key frames using the modified Hausdorff distance. Experimental results with real sequence show that the proposed video sequence matching algorithm using edge features yields the higher accuracy and performance than conventional methods such as histogram difference, Euclidean metric, Battachaya distance, and directed divergence methods.

Molecular Phylogeny and Divergence Time Estimation of the Soft Coral Dendronephthya gigantea (Alcyonacea: Nephtheidae)

  • Kim, Boa;Kong, So-Ra;Song, Jun-Im;Won, Yong-Jin
    • Animal Systematics, Evolution and Diversity
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    • v.24 no.3
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    • pp.327-332
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    • 2008
  • Soft coral Dendronephthya gigantea (Verrill, 1864) is a conspicuous species dominating shallow sea waters of Jejudo Island, Korea. Recently its whole mitochondrial genome sequencing was completed by us and the sequence information provided an opportunity to test the age of Octocorallia and time of evolutionary separation between some representative orders of the subclass Octocorallia. Molecular phylogenetic analyses based on 13 mitochondrial protein encoding genes revealed a polyphyletic relationship among octocorallians representing two orders (Alcyonacea and Gorgonacea) and four families (Alcyoniidae, Nephtheidae, Briareidae, and Gorgoniidae). Estimates of divergence times among octocorallians indicate that the first splitting might occur around end of or after Cretaceous period (50-79 million years ago (Ma)). The age is relatively young compared to the long history of stony sea corals (>240 Ma). Taken together our result suggests a possible relatively recent radiating evolution at least in the order Alcyonacea and Gorgonacea. Molecular dating and phylogenetic analysis based on much broader taxon sampling and many genes might give an insight into this interesting hypothesis.

Exploring the Utility of Partial Cytochrome c Oxidase Subunit 1 for DNA Barcoding of Gobies

  • Jeon, Hyung-Bae;Choi, Seung-Ho;Suk, Ho Young
    • Animal Systematics, Evolution and Diversity
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    • v.28 no.4
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    • pp.269-278
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    • 2012
  • Gobiids are hyperdiverse compared with other teleost groups, with about 2,000 species occurring in marine, freshwater, and blackish habitats, and they show a remarkable variety of morphologies and ecology. Testing the effectiveness of DNA barcodes on species that have emerged as a result of radiation remains a major challenge in evolutionary biology. Here, we used the cytochrome c oxidase subunit 1 (COI) sequences from 144 species of gobies and related species to evaluate the performance of distance-based DNA barcoding and to conduct a phylogenetic analysis. The average intra-genus genetic distance was considerably higher than that obtained in previous studies. Additionally, the interspecific divergence at higher taxonomic levels was not significantly different from that at the intragenus level, suggesting that congeneric gobies possess substantial interspecific sequence divergence in their COI gene. However, levels of intragenus divergence varied greatly among genera, and we do not provide sufficient evidence for using COI for cryptic species delimitation. Significantly more nucleotide changes were observed at the third codon position than that at the first and the second codons, revealing that extensive variation in COI reflects synonymous changes and little protein level variation. Despite clear signatures in several genera, the COI sequences did resolve genealogical relationships in the phylogenetic analysis well. Our results support the validity of COI barcoding for gobiid species identification, but the utilization of more gene regions will assist to offer a more robust gobiid species phylogeny.

Comparative study: nonsynonymous and synonymous substitution of SARS-CoV-2, SARS-CoV, and MERS-CoV genome

  • Sohpal, Vipan Kumar
    • Genomics & Informatics
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    • v.19 no.2
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    • pp.15.1-15.7
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    • 2021
  • The direction of evolution can estimate based on the variation among nonsynonymous to synonymous substitution. The simulative study investigated the nucleotide sequence of closely related strains of respiratory syndrome viruses, codon-by-codon with maximum likelihood analysis, z selection, and the divergence time. The simulated results, dN/dS > 1 signify that an entire substitution model tends towards the hypothesis's positive evolution. The effect of transition/transversion proportion, Z-test of selection, and the evolution associated with these respiratory syndromes, are also analyzed. Z-test of selection for neutral and positive evolution indicates lower to positive values of dN-dS (0.012, 0.019) due to multiple substitutions in a short span. Modified Nei-Gojobori (P) statistical technique results also favor multiple substitutions with the transition/transversion rate from 1 to 7. The divergence time analysis also supports the result of dN/dS and imparts substantiating proof of evolution. Results conclude that a positive evolution model, higher dN-dS, and transition/transversion ratio significantly analyzes the evolution trend of severe acute respiratory syndrome coronavirus 2, severe acute respiratory syndrome coronavirus, and Middle East respiratory syndrome coronavirus.

Analysis of ITS Nucleotide Sequences in Ribosomal DNA of Morus Species (뽕나무속 식물의 ITS 영역 염기서열 분석)

  • 성규병;류근섭;김호락;남학우;구태원
    • Journal of Sericultural and Entomological Science
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    • v.43 no.1
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    • pp.1-8
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    • 2001
  • Nucleotide sequence in internal transcribed spacer (ITS) regions of ribosomal DNA among mulberry varieties (Morus species) were analyzed in order to identify the possibility of classification for the species. The variations in the ITS regions were compared among 9 mulberry varieties and one variety of Cudrania species as an outgroup. ITS 1 region of the varieties ranging from 219 to 220 bp in length was 49-50 bp shorter than ITS 2 region. Of 510 sites in the ITS 1 and 2 regions, 148 sites were potentially variable, of which 52% and 48% sites were distributed in ITS 1 and ITS 2 regions, respectively. By pairwise comparisons on the nucleotide sequences in the ITS 1 and 2 regions among 9 mulberry varieties, they were classified into 5 groups. Divergence values of the sequences, however, were considerably low ranging from 0 to 1.3%. Especially, there was no divergence among Backasipmunja, Chungilppong and Milsungpong and Jungyasang, Ssarigol II and Yulbon, respectively.

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New Family Gulgastruridae of Collembola (Insecta) Based on Morphological, Ecobiological and Molecular Data

  • Byung Hoon Lee;Jean Marc Thibaud
    • Animal cells and systems
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    • v.2 no.4
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    • pp.451-454
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    • 1998
  • Gulgastrura reticulosa, first described by Yosii (1966) as a monotypic new genus from a Korean limestone cave, was reviewed for its systematic position by c1adistic analysis of morphological characteristics, investigation of its intermaulting period and reproductive cycle as well as allozyme and 18S rDNA analysis. The great extent of divergence was strongly suggested by its combined lack of sensory organs (third antennal organ, postantennal organ, eyes, pseudocelli) with simultaneous development of an 'apical organ'at the tip of the antennae. The obvious divergence from any existing Collembola families was additionally supported by the extremely prolonged intermoulting period as well as by the low strap value it showed with Onychiuridae as obtained by 18S DNA sequence analysis. All these were considered Justifying the creation of a new family, Gulgastruridae, but still revealing more allied to Onychiuvidae rather than to Hypogastruridae.

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The Complete Genome Sequence of Southern rice black-streaked dwarf virus Isolated from Vietnam

  • Dinh, Thi-Sau;Zhou, Cuiji;Cao, Xiuling;Han, Chenggui;Yu, Jialin;Li, Dawei;Zhang, Yongliang
    • The Plant Pathology Journal
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    • v.28 no.4
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    • pp.428-432
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    • 2012
  • We determined the complete genome sequence of a Vietnamese isolate of Southern rice black-streaked dwarf virus (SRBSDV). Whole genome comparisons and phylogenetic analysis showed that the genome of the Vietnamese isolate shared high nucleotide sequence identities of over 97.5% with those of the reported Chinese isolates, confirming a common origin of them. Moreover, the greatest divergence between different SRBSDV isolates was found in the segments S1, S3, S4 and S6, which differs from the sequence alignment results between SRBSDV and Rice black streaked dwarf virus (RBSDV), implying that SRBSDV evolved in a unique way independent of RBSDV. This is the first report of a complete nucleotide sequence of SRBSDV from Vietnam and our data provides new clues for further understanding of molecular variation and epidemiology of SRBSDV in Southeast Asia.

Mitochondrial DNA Sequence Variation of the Mason Bee, Osmia cornifrons (Hymenoptera: Apidae)

  • Kim, Hwa-Young;Lee, Kyeong-Yong;Lee, Sang-Beom;Kim, Se-Ryeon;Hong, Mee-Yeon;Kim, Dong-Young;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.16 no.2
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    • pp.75-86
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    • 2008
  • In order to understand geographic genetic variation and relationship among populations of the mason bee (Osmia cornifrons Radoszkowsky), which is used as pollinator for apple tree, we sequenced a portion of mitochondrial (mt) COI gene, which corresponds to "DNA Barcode" region (658 bp) from 81 O. cornifrons individuals collected over eight localities in Korea. The sequence data revealed overall moderate to low genetic diversity within species, with a maximum sequence divergence of 0.76%. Geographically, two haplotypes (BAROC01 and BAROC02) were widespread with a frequency of 82.7%, whereas several haplotypes were found in a locality as a single individual, suggesting that haplotype distribution can be summarized as coexistence of a few widespread haplotypes and several regionally restricted haplotypes. Overall, high rate of per generation female migration (Nm=$1.1{\sim}$infinite) and low level of geographic subdivision ($F_{ST}=0{\sim}0.315$) among localities were characteristic. Although two populations (p < 0.026) were genetically subdivided from the remaining localities, no clear polarity was observed. Taken together, the nature of genetic divergence of the mason bee populations is characterized as one that possessing moderate to low genetic diversity, high gene flow, and wide spread haplotypes with ahigh frequency, concordant with the capability of dispersal in connection with the lack of historical biogeographic barriers.

Population Genetic Structure of the Bumblebee, Bombus ignitus (Hymenoptera: Apidae), Based on Mitochondrial COI Gene and Nuclear Ribosomal ITS2 Sequences

  • Oh, Hyung Keun;Yoon, Hyung Joo;Lee, Joo Young;Park, Jeong Sun;Kim, Iksoo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.27 no.1
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    • pp.142-158
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    • 2013
  • The bumblebee, Bombus ignitus (Hymenoptera: Apidae), is a valuable natural resource that is widely utilized for greenhouse pollination in South Korea. Understanding the magnitude of genetic diversity and geographic relationships is of fundamental importance for long term preservation and utilization. As a first step, we sequenced a partial COI gene of mitochondrial DNA (mtDNA) corresponding to the "DNA barcode" region and the complete internal transcribed spacer 2 (ITS2) of nuclear ribosomal DNA from 88 individuals collected in nine South Korean localities. The complete ITS2 sequences were longest among known insects, ranging in size from 2,034 bp ~ 2,052 bp, harboring two duplicated 112-bp long repeats. The 658-bp long mtDNA sequences provided only six haplotypes with a maximum sequence divergence of 0.61% (4 bp), whereas the ITS sequences provided 84 sequence types with a maximum sequence divergence of 1.02% (21 sites). The combination of the current COI data with those of published data suggest that the B. ignitus in South Korea and China are genetically a large group, but those in Japan can be roughly separated into another group. Overall, a very high per generation migration ratio, a very low level of genetic fixation, and no discernable hierarchical population were found to exist among the South Korean populations of B. ignitus, which suggests panmixia. This finding is consistent with our understanding of the dispersal capability of the species.

Intronic Sequences for the Discrimination of Silkworm Strains in Silkworm Powder

  • Kim, Kee-Young;Lee, Eun-Mee;Hong, Mee-Yeon;Kang, Pil-Don;Ryu, Kang-Sun;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.15 no.2
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    • pp.93-100
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    • 2007
  • After a serial study on the therapeutic efficacy of the powdery silkworm for diabetics was positively resulted in, many powdery silkworm products were on the market in Korea. Up to now, however, no causal method is available to discriminate the strain of silkworms that is a major ingredient for manufacturing powdery silkworm, even though the quality of the powdery silkworm differs greatly by source and origin of strains. We previously were successful in identifying 25 silkworm strains kept in Korea using nine intronic sequences. In this study, we tested the utility of the nine intronic sequences to distinguish the most widely reared silkworm strains originated from Korea and China. Two intron regions, PTTH Intron3 and PTTH Intron3, showed a substantial sequence divergence (mean sequence divergence of 3.13% in PTTH Intron3 and 4.99% in PTTH Intron3). These two intronic sequences provided no identical sequences among the seven strains tested. Thus, these sequences each along can be used to discriminate the seven strains tested in this study. Furthermore, other intron regions, except for VDP Intron4 allowed us to discriminate $2{\sim}4$ strains by strain-specific unique insertion/deletion or substitution.