• Molecules and Cells
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• 제27권2호
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• pp.205-209
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• 2009

The loci of the 5S and 45S rRNA genes were localized on chromosomes in five species of Capsicum, namely, annuum, chacoense, frutescens, baccatum, and chinense by FISH. The 5S rDNA was localized to the distal region of one chromosome in all species observed. The number of 45S rDNA loci varied among species; one in annuum, two in chacoense and frutescens, and chinense, and four in baccatum, with the exceptions that 'CM334' of annuum had three loci and 'tabasco' of frutescens gad one locus. 'CM334'-derived BAC clones, 384B09 and 365P05, were screened with 5S rDNA as a probe, and BACs 278M03 and 262A23 were screened with 25S rDNA as a probe. Both ends of these BAC clones were sequenced. FISH with these BAC probes on pachytenes from 'CM334' plant showed one 5S rDNA locus and three 45S rDNA loci, consistent with the patterns on the somatic chromosomes. The 5S rDNA probe was also applied on extended DNA fibers to reveal that its coverage measured as long as 0.439 Mb in the pepper genome. FISH techniques applied on somatic and meiotic chromosomes and fibers have been established for chili to provide valuable information about the copy number variation of 45S rDNA and the actual physical size of the 5S rDNA in chili.

• ALGAE
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• 제25권2호
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• pp.65-70
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• 2010

The genus Chaetoceros provides highly diversified diatoms in marine systems. Morphological descriptions of the genus are well-documented, yet the DNA taxonomy of Chaetoceros has not been satisfactorily established. Here, the molecular divergences of the 18S-28S rDNA of Chaetoceros were assessed. DNA similarities were relatively low in both 18S (93.1 $\pm$ 3.9%) and 28S rDNA (81.0 $\pm$ 4.6%). Phylogenies of the 18S, 28S rDNAs showed that Chaetoceros was divided according to individual species, clustering the same species into single clades. Statistical analysis with corrected genetic (p-) distance scores showed that nucleotide divergence of Chaetoceros 28S rDNA significantly differed from that of 18S rDNA (Student's t-test, p < 0.05). This finding suggests that the 28S rDNA may be treated as a more suitable marker for species-level taxonomic distinctions of Chaetoceros.

• The Plant Pathology Journal
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• 제25권1호
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• pp.21-25
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• 2009

Jujube trees infected with phytoplasma exhibit symptoms of typical witches' broom, such as yellowing, abnormally small leaves, short internodes and proliferation of shoots. A 1.2 kb fragment of the 16S rDNA from jujube phytoplasma was generated by R16F2n/R16R2 primer pair from earlier amplified P1/P7 PCR products of cloned jujube witches' broom phytoplasmas. Enzymatic restriction fragment length polymorphism (RFLP) and sequence analysis of 16S rDNA revealed that the jujube tree was infected with 16S rDNA I and V groups of phytoplasmas. Extensive comparative analyses of restriction enzyme profiles from Alu I, Hha I, Msp I, and Rsa I clearly classified the two into different phytoplasma groups. The phylogenie analyses based on 16S rDNA showed that the similarity of the two different clones was 87.5%. This is the first report of a mixed phytoplasmal infection in a single jujube tree.

• 한국약용작물학회지
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• 제14권3호
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• pp.178-182
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• 2006

둥굴레 유전자원의 유연관계를 위한 기초 자료를 얻고자 둥굴레속 식물 수집종 10종에서 18S ribosomal RNA를 암호화하는 18S rDNA 영역의 염기서열을 결정하고 그 특성을 분석한 결과를 요약하면 다음과 같다. 둥굴레속 10종의 18S rDNA 영역 전체의 길이는 $913{\sim}914bp$로 비슷하였으나, 총 8개 지점에서 염기의 치환 및 결실에 의한 변이가 발생하였다. 전위는 $T{\rightarrow}C$전위가 4개 지점에서 발생하였고, $A{\rightarrow}G$ 전위가 1개 지점에서 발생하였으며, 전좌는 $C{\rightarrow}A$ 전좌가 1개 지점에서 발생하여 전위가 전좌보다 5배 만큼 발생하였다. 결실은 2개 지점에서 발생하였다. 18S rDNA의 염기의 조성은 adenine $23.09{\sim}23.33%$, guanine $23.33{\sim}23.52%$, thymine $25.60{\sim}25.85%$, cytosine $27.38{\sim}27.79%$로 pyrimidine계가 purine계보다 많았다. 18S rDNA의 A + T 함량은 $48.80{\sim}49.18%$로 평균 48.99%였고, G+C 함량은 $50.82{\sim}51.20%$로 평균51.01%였다. 다중 정렬에 의해 염기서열을 비교한 결과 $99.7{\sim}100%$ 일치하여 종간에 차이가 적었다.

• Animal Systematics, Evolution and Diversity
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• 제36권4호
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• pp.382-386
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• 2020

In this study, Prionospio depauperata Imajima, 1990 is newly reported in Korean fauna. Prionospio depauperata can be distinguished from other relatives by the four pairs of branchiae which are pinnate on chaetigers 2 and 5, and apinnate on chaetigers 3 and 4; caruncle extending to the end of chaetiger 2; and moderate dorsal crest present on chaetigers 7-13. The morphological diagnosis of P. depauperata are provided with the photographs of four Prionospio species. The mitochondrial cytochrome c oxidase subunit 1 (CO1), 16S ribosomal DNA (16S rDNA), and the nuclear 18S ribosomal DNA (18S rDNA) sequences of four Prionospio species from Korean waters, P. depauperata Imajima, 1990, P. japonica Okuda, 1935, P. krusadensis Fauvel, 1929, and P. membranacea Imajima, 1990, were determined for the first time. The inter-specific genetic distances among the congeners of four Prionospio species were 22.3-29.6% in CO1, 10.5-25.0% in 16S rDNA, and 0.3-3.6% in 18S rDNA.

• 미생물학회지
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• 제39권1호
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• pp.36-39
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• 2003

본 연구에서는 16S rDNA복합중합효소연쇄반응을 이용하여 중이 삼출액에서 미생물병인원에 대한 특성을 알아보았다. 중이염환자의 중이 삼출액에서의 미생물 병인원은 주로 streptococcus pneumoniae, Haemophilus influenzae와 Moraxella catarrhalis이다. 26명의 환자로부터 39개의 중이염의 삼출액을 얻었고, 중이 삼출액에서 DNA를 추출하였다. PCR은 16S rDNA의 C4 region에서 21 base pair의 common primer와 각각 bacterium specific primers [(i) Haemophilus-specific primer (ii) Moraxella-specific primer and (iii) Streptococcus-specific primer]를 이용하여 수행하였다. 39 개의 중이염의 삼출액 시료 중에서, H. influenzae가 24 개(61.5%) 검출되었고, M. catarrhalis는 10 개(25.6%), S.pneumoniae는 3개 (7.7%)가 검출되었다. 16s rDNA 복합중합효소연쇄 반응 진단 결과,11 개(28%)의 중이삼출액 시료에서 음성을 나타내었다. 중이염의 중복감염은 9개의 중이 삼출액시료에서 관찰되었고, 이들은 모두 H.influenzae 와 M. catarrhalis 에 의한 중복감염이었다. 본 연구에서 저자 등은 165 rDNA 복합중합효소연쇄반응이 병원성 미생물을 빠르게 진단하고, 중이삼출액의 미생물 병인론을 추적할 수 있는 좋은 방법으로 제시하는 바이다.

• 미생물학회지
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• 제37권1호
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• pp.9-14
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• 2001

서울시내 25개 자치구에 산재한 약수터에서 5주의 Yersinia pseudotuberculosis를 분리하여 생화학적 특성, 병원성의 유무 및 16S rDNA 분석을 실시하였다. 분리된 Y. pseudotuberculosis는 모두 병원성 유전자인 inv를 소유하고 있었으며, 16S rDNA를 증폭한 후 염기서열을 분석하여 NCBI Genbank에 등록된 다른 Yersinia 속 및 장내세균 등과 비교해 본 결과 Yersinia 속 등과는 97.5%에서 100%의 높은 상동성(Similarity)을 나타내었고, 다른 장내세균 등과는 93.0%에서 95.1%의 낮은 상동성을 나타내었다. 165 rDNA 염기서열을 기초로 계통수를 작성한 결과 크게 3개의 cluster를 형성하였는데 특히 Y.enterocolitica (Z49830)은 Y.pseudotuberculasis (Z21939)와의 상동성(97.7%)보다 Y.intermedia (X75279)와의 상동성(97.9%)이 더 높게 나타났으며, E. coli (Z83205)는 Proteus vulgaris (AJ233425) 와의 상동성(93.2%)보다 Salmonella enteritidis (U90318)와의 상동성(97.7%)이 더 밀접한 연관성을 나타내었다.

• Journal of Microbiology
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• 제33권2호
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• pp.136-141
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• 1995

From a cluster of structural rRNA genes which has previsouly been cloned (Hwang and Kim, in submission; J. Microbiol. Biotechnol.), a 1.0-kb Eco RI fragment of DNA which shows significant homology to the 25S and rRNA s of Tricholoma matsutake was used for sequence analysis. Nucleotide sequence was bidirectionally determined using delection series of the DNA fragment. Comparing the resultant 1016-base sequence with sequences in the database, both the 3'end of 25S-rRNA gene and 5S rRNA gene were searched. The 5S rRNA gene is 118-bp in length and is located 158-bp downstream of 3'end of the 25S rRNA gene. IGSI and IGS2 (partial) sequences are also contained in the fragment. Multiple alignment of the 5S rRNA sequences was carried out with 5S rRNA sequences from some members of the subdivision Basidiomycotina obtained from the database. Polygenetic analysis with distance matrix established by Kimura's 2-parameter method and phylogenetic tree by UPGMA method proposed that T. matsutake is closely related to efibulobasidium allbescens. Secondary structure of 5S rRNA was also hypothesized to show similar topology with its generally accepted eukaryotic counterpart.

• Bulletin of the Korean Chemical Society
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• 제25권9호
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• pp.1430-1432
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• 2004

• The Plant Pathology Journal
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• 제40권2호
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• pp.171-191
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• 2024

Identification of Helicotylenchus species is very challenging due to phenotypic plasticity and existence of cryptic species complexes. Recently, the use of rDNA barcodes has proven to be useful for identification of Helicotylenchus. Molecular markers are a quick diagnostic tool and are crucial for discriminating related species and resolving cryptic species complexes within this speciose genus. However, DNA barcoding is not an error-free approach. The public databases appear to be marred by incorrect sequences, arising from sequencing errors, mislabeling, and misidentifications. Herein, we provide a comprehensive analysis of the newly obtained, and published DNA sequences of Helicotylenchus, revealing the potential faults in the available DNA barcodes. A total of 97 sequences (25 nearly full-length 18S-rRNA, 12 partial 28S-rRNA, 16 partial internal transcribed spacer [ITS]-rRNA, and 44 partial cytochrome c oxidase subunit I [COI] gene sequences) were newly obtained in the present study. Phylogenetic relationships between species are given as inferred from the analyses of 103 sequences of 18S-rRNA, 469 sequences of 28S-rRNA, 183 sequences of ITS-rRNA, and 63 sequences of COI. Remarks on suggested corrections of published accessions in GenBank database are given. Additionally, COI gene sequences of H. dihystera, H. asiaticus and the contentious H. microlobus are provided herein for the first time. Similar to rDNA gene analyses, the COI sequences support the genetic distinctness and validity of H. microlobus. DNA barcodes from type material are needed for resolving the taxonomic status of the unresolved taxonomic groups within the genus.