• Title/Summary/Keyword: molecular systematics

검색결과 153건 처리시간 0.025초

Molecular Systematics of the Genus Megoura (Hemiptera: Aphididae) Using Mitochondrial and Nuclear DNA Sequences

  • Kim, Hyojoong;Lee, Seunghwan
    • Molecules and Cells
    • /
    • 제25권4호
    • /
    • pp.510-522
    • /
    • 2008
  • To construct the molecular systematics of the genus Megoura (Hemiptera: Aphididae), DNA based-identification was performed using four mitochondrial and three nuclear DNA regions: partial cytochrome c oxidase I (COI), partial tRNA-leucine + cytochrome c oxidase II (tRNA/COII), cytochrome b (CytB), partial 12S rRNA + tRNA-valine + 16S rRNA (12S/16S), elongation factor-1 alpha ($EF1{\alpha}$), and the internal transcribed spacers 1 and 2 (ITS1, ITS2). Pairwise sequence divergences between taxa were compared, and phylogenetic analyses were performed based on each DNA region separately, and the combined datasets. COI, CytB, $EF1{\alpha}$, ITS1, and ITS2 were relatively effective in determining species and resolving their relationships. By contrast, the sequences of tRNA/COII and 12S/16S were not able to separate the closely related species. CytB and $EF1{\alpha}$ gave better resolution with higher average sequence divergences (4.7% for CytB, 5.2% for $EF1{\alpha}$). The sequence divergence of COI (3.0%) was moderate, and those of the two ITS regions (1.8% for ITS1, 2.0% for ITS2) were very low. Phylogenetic trees were constructed by minimum evolution, maximum parsimony, maximum likelihood, and Bayesian phylogenetic analyses. The results indicated that the phylogenetic relationships between Megoura species were associated with their host preferences. Megoura brevipilosa and M. lespedezae living on Lespedeza were closely related, and M. nigra, monophagous on Vicia venosa, was rather different from M. crassicauda, M. litoralis, and M. viciae, which are oligophagous on Lathyrus and Vicia. The three populations of M. crassicauda formed a clade separated from M. litoralis and M. viciae. Nevertheless M. litoralis and M. viciae, which are morphologically similar, were not separated due to negligible sequence divergence. We discuss the phylogenetic relationships of the Megoura, and the usefulness of the seven DNA regions for determining the species level phylogeny of aphids.

트레이닝 데이터 생성과 의사 결정 트리를 이용한 계통수 생성 방법 (The Training Data Generation and a Technique of Phylogenetic Tree Generation using Decision Tree)

  • 채덕진;신예호;천태영;고흥선;류근호;황부현
    • 정보처리학회논문지D
    • /
    • 제10D권6호
    • /
    • pp.897-906
    • /
    • 2003
  • 전통적인 동물 계통수(系統樹)는 초기발생 혈질에 기초하여 몸 구조가 단순한 것에서 복잡한 것으로 동물문(animal phylum)들을 배열하는 것이다. 현재 활발하게 연구 진행되는 분자수준에서의 분자계통 분류학(Molecular Systematics) 연구들이 이런 경향을 재평가하고 새로운 계통과 진화의 의미를 제시하고 있다. 본 논문에서는 한 염기서열로부터 획득할 수 있는 특성 값들을 추출하여 트레이닝 데이터를 생성하고, 생성된 데이터를 기반으로 데이터마이닝 기법중의 하나인 분류기법(classification) 을 사용하여 계통수를 생성하였다. 실험용 데이터는 미토콘드리아 염기서열을 사용하였으며 생물학분야에서 사용하는 분석 프로그램인 MEGA 프로그램을 사용하여 이를 증명하였다. 비록 마이닝을 수행한 결과는 생물학적 실험을 거쳐 정확성을 검증 받아야 하지만 인터넷상에 떠다니는 무수한 유전체들에 대한 유효한 분류기준을 제시할 수 있고 계통수 제작을 위한 실험에 소요되는 많은 시간과 노력들을 줄일 수 있다.

Ultrastructural and Molecular Characterization of Surirella atomus Hustedt 1955 (Bacillariophyta, Surirellalceae), A Newly Recorded Species in Korea

  • An, Sung Min;Noh, Jae Hoon;Kim, Ji Hoon;Kang, Nam Seon
    • Ocean and Polar Research
    • /
    • 제43권4호
    • /
    • pp.245-253
    • /
    • 2021
  • Surirella atomus Hustedt 1955, surirelloid diatom, were obtained from Hampyeong Bay, Mu-an, in the west coast of Korea. We describe the first record of S. atomus in Korea and report its ultrastructure and molecular characteristics for the first time. For molecular analysis, rbcL gene and cob gene were sequenced. This species is very small in size, making it difficult to observe its morphological features under a light microscope. Even with a scanning electron microscope, it has no unique structure in the valve. It is morphologically very simple. This rare species was known as a marine benthic species. However, it appears to be widely distributed in marine, freshwater, and brackish environments according to the literature documenting this species. In terms of phylogeny, S. atomus has been tentatively linked to Petrodictyon gemma, but the phylogenetic placement of S. atomus seems to be still uncertain, in a manner that is similar to S. febigeri. However, morphological observations derived from this study suggest that this species belongs to the genus Surirella.

Cryptic variation, molecular data, and the challenge of conserving plant diversity in oceanic archipelagos: the critical role of plant systematics

  • Crawford, Daniel J.;Stuessy, Tod F.
    • 식물분류학회지
    • /
    • 제46권2호
    • /
    • pp.129-148
    • /
    • 2016
  • Plant species on oceanic islands comprise nearly 25% of described vascular plants on only 5% of the Earth's land surface yet are among the most rare and endangered plants. Conservation of plant biodiversity on islands poses particular challenges because many species occur in a few and/or small populations, and their habitats on islands are often disturbed by the activity of humans or by natural processes such as landslides and volcanoes. In addition to described species, evidence is accumulating that there are likely significant numbers of "cryptic" species in oceanic archipelagos. Plant systematists, in collaboration with others in the botanical disciplines, are critical to the discovery of the subtle diversity in oceanic island floras. Molecular data will play an ever increasing role in revealing variation in island lineages. However, the input from plant systematists and other organismal biologists will continue to be important in calling attention to morphological and ecological variation in natural populations and in the discovery of "new" populations that can inform sampling for molecular analyses. Conversely, organismal biologists can provide basic information necessary for understanding the biology of the molecular variants, including diagnostic morphological characters, reproductive biology, habitat, etc. Such basic information is important when describing new species and arguing for their protection. Hybridization presents one of the most challenging problems in the conservation of insular plant diversity, with the process having the potential to decrease diversity in several ways including the merging of species into hybrid swarms or conversely hybridization may generate stable novel recombinants that merit recognition as new species. These processes are often operative in recent radiations in which intrinsic barriers to gene flow have not evolved. The knowledge and continued monitoring of plant populations in the dynamic landscapes on oceanic islands are critical to the preservation of their plant diversity.

A Taxonomic Study on Perinereis nuntia Species Group (Polychaeta: Nereididae) of Korea

  • Park, Tae-Seo;Kim, Won
    • Animal Systematics, Evolution and Diversity
    • /
    • 제23권1호
    • /
    • pp.75-85
    • /
    • 2007
  • A taxonomic study was carried out on the Perinereis nuntia species group of Korea by using morphological and molecular data (mitochondrial cytochrome c oxidase subunit I: mtCOI). Two species, P. mictodonta (Marenzeller, 1879) and P. wilsoni (Glasby and Hsieh, 2006), are recognized and redescribed. In this study, mtCOI gene showed a good resolution as molecular marker for species identification of the P. nuntia species group of Korea.

울릉도 해역의 단각류(갑각류) II (The Marine Amphipod Crustaceans of Ulreung Island, Korea : Part II)

  • 김원;김창배
    • Animal Systematics, Evolution and Diversity
    • /
    • 제7권1호
    • /
    • pp.13-38
    • /
    • 1991
  • This study on the five families (Anamixidae, Colomastigidae, Eophliantidae, Eusiridae, and Hyalidae) of fammaridean amphipods of Ulreung Island was based on the materials collected at eight localities in Ulreung Island. Nine speices of seven genera were identified. Of these, three (Paranamixis denticulus, Colomastix prionotos, and Hyale bisaeta) were new to science. Three species (Ceinina japonica, Eusiroides monoculoides japonicus, and Allorchestes angusta) were new recordsfor Korean waters. These six species were descirbed with illustrations.

  • PDF

한국산 집게류에 공생하는 요각류 2종 (Two species of Porcellidiidae (Copepoda, Harpacticoida) associated with hermit crabs from Korea)

  • 김사흥;김원
    • Animal Systematics, Evolution and Diversity
    • /
    • 제12권4호
    • /
    • pp.375-387
    • /
    • 1996
  • Two species of the family Porcellidiidae associated with hermit crabs are described from Korean seas. These are Porcellidium similis, new species collected from Pagurus similis, Pagurus pectinatus and Porcellidium brevicaudatum Kicks & Webber collected from Dardanus impressus. The new species resemble closely Porcellidium brevicaudatum in general body form, but is clearly distinguished from Porcellidium vrevicaudatum in that the caudal ramus is weakly oblique in tis distal border and the lobe of leg 5 is more slender.

  • PDF