• ALGAE
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• 제19권2호
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• pp.79-90
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• 2004

Nuclear DNA contents of spermatia from eight ceramiacean and four dasyacean algae (Ceramiales, Rhodophyta) and microspores from two land plants were estimated by fluorescence microscopic image processing and their nuclear SSU rDNA sequence data were analyzed. In frequency distribution patterns, the DAPI-stained nuclear volume (NV) of spermatia showed two peaks corresponding to 1C and 2C. Nuclear 2C DNA contents estimated from NV were 0.45-2.31 pg in ceramiacean and 0.40-0.57 pg in dasyacean algae and 8.42-9.51 pg in two land plants, Capsicum annuum and Nicotiana tabacum. By nuclear patterning of vegetative cells derived from an apical cell, 2C DNA contents of spermatia were 2.31 pg in an alga having uninucleate and non-polyploid nucleus (Aglaothamnion callophyllidicola), 0.45-1.94 pg in algae having uninucleate and polyploid nucleus (Antithamnion spp. and Pterothamnion yezoense), and 0.40-0.62 pg in algae having multinucleate and non-polyploid nuclei (Griffithsia japonica and dasyacean algae). Each mature spermatium and microspore (pollen grain) seemed to have a 2C nucleus, which may provide a genetic buffering system to protect the genetic content of a spermatium and microspore from potentially lethal mutations. Nuclear DNA content and SSU rDNA sequence of Antithamnion sparsum from Korea were reasonably different from those of Antithamnion densum from France. The data did not support the previous taxonomic studies that these two taxa could be conspecific.

• Parasites, Hosts and Diseases
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• 제49권3호
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• pp.281-284
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• 2011

Amebiasis is a protozoan disease caused by Entamoeba histolytica and a potential health threat in areas where sanitation and hygiene are inappropriate. Highly sensitive PCR methods for detection of E. histolytica in clinical and environmental samples are extremely useful to control amebiasis and to promote public health. The present study compared several primer sets for small subunit (SSU) rDNA and histone genes of E. histolytica cysts. A 246 bp of the SSU rDNA gene of pure cysts contained in phosphate-buffered saline (PBS) and in stool samples was successfully amplified by nested PCR, using the 1,147-246 bp primer set, of the primary PCR products which were pre-amplified using the 1,147 bp primer as the template. The detection limit of the nested PCR using the 1,147-246 primer set was 10 cysts in both groups (PBS and stool samples). The PCR to detect histone gene showed negative results. We propose that the nested PCR technique to detect SSU rDNA can be used as a highly sensitive genetic method to detect E. histolytica cysts in stool samples.

• 생명과학회지
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• 제14권4호
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• pp.593-607
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• 2004

유해성 적조생물 Cochlodinium polykrikoides/Gyrodinium aurelum을 포함한 43 종류의 와편조류를 대상으로 SSU 부위 유전자를 분석했다. 유전자 염기서열에 의거한 상호 계통수는 parisomny, distance, maxium 방법으로 실행했다. Noctilura scintillans, Gonyaulax spinifera와 Crythecodinium cohnii 종들은 와편모조류 중 가장 유전적으로 먼 것으로 보였다. Alexandrium과 Symbiodinium 종간의 bootstrap는 70% 이상의 상호 단일 계통도를 보인 반면에, Gymnodinium과 Gyrodinium은 근립절약계수와 최대 유사도 방법에서 다형 계통도를 나타내었다. Gyroddinium aurelum과 G. dorsum/G. galathenum의 유전적 분화율은 7.4% (45 bp) 였고, G. aurelum과 G. mikimotoi 상호간에는 0.9% (5bp) 밖에 나타나지 않았다. 또한 C. polykrikoides와 G. aurelum도 5.2% (31bp)로 낮은 유전적 분화율을 보였다. 계통도를 분석한 결과 G. aureolum과 C. polykrikoides는 Gyrodinium 보다 Gymnodinim 속에 훨씬 더 근접하게 나타났다.

• ALGAE
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• 제38권4호
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• pp.241-252
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• 2023

The genera Carolibrandtia and Chlorella have been described as small green algae with spherical cell shapes that inhabit various environments. Species of these genera are often difficult to identify because of their simple morphology and high phenotypic plasticity. We investigated two small coccoid strains from Antarctica based on morphology, molecular phylogeny by two alignment methods which have been applied to previous phylogenetic studies of the genus Chlorella, and comparison of the secondary structures of nuclear small subunit (SSU) and internal transcribed spacer (ITS) rDNA sequences. Light microscopy of two strains revealed spherical cells containing chloroplasts with pyrenoids, and the morphological characteristics of the strains were nearly identical to those of other Chlorella species. However, based on the phylogenetic analyses of nuclear SSU and ITS rDNA sequences, it was determined that the Antarctic microalgal strains belonged to two genera, as the Chlorella and Carolibrandtia. In addition, the secondary structures of the SSU and ITS2 sequences were analyzed to detect compensatory base changes (CBCs) that were used to identify and describe the two strains. A unique CBC in the SSU rDNA gene was decisive for distinguishing strain CCAP 211/45. The ITS2 rDNA sequences for each strain were compared to those obtained previously from other closely related species. Following the comparison of morphological and molecular characteristics, we propose KSF0092 as a new species, Chlorella terrestris sp. nov., and the reassignment of the strain Chlorella antarctica CCAP 211/45 into Carolibrandtia antarctica comb. nov.

• ALGAE
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• 제20권1호
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• pp.25-30
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• 2005

To clarify some confusions concerning identification of the Korean Peridinium species, genotypic analysis was performed with their SSU rDNA sequences. PCR was used to amplify the partial SSU rDNA of Peridinium isolates collected from three different Korean waters (Juam, Sang-sa and Togyo Reservoirs). The PCR products were allowed directly to sequence, which revealed each 942 bp of rDNA sequence. Analyses of the rDNA sequences showed that all the Korean isolates had the same genotype (100% sequence homology), and they were nearly identical to a Japanese strain of P. bipes f. occultatum (NIES 364; 99.8% sequence similarity). The sequence-based comparisons could clearly resolve P. bipes f. occultatum isolated from three different Korean waters.

• ALGAE
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• 제22권3호
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• pp.147-152
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• 2007

We described two brownish freshwater Cryptomonas species, C. marssonii Skuja and C. pyrenoidifera Geitler as first records in Korea. The identification was based on light microscopy, scanning electron microscopy, and nuclear SSU rDNA sequences analysis. Cryptomonas marssonii is characterized by its sigmoid shape with a sharply pointed and dorsally curved antapex, dorso-ventrally flattened cell, two lateral plastids without pyrenoid, and its dimension of 18-25 μm in length and 8-13 μm in width. Cryptomonas pyrenoidifera is characterized by ovoid to elliptical shape with a partially twisted or rounded antapex, dorso-ventrally biconvex cell, lateral plastids with two pyrenoids, and the dimensions of 15-22 μm in length and 10-14 μm in width. Nuclear SSU rDNA sequences between C. marssonii WCK01 from Korea and CCAC0086 from Gernmay, and between C. pyrenoidifera WCK02 from Korea and CCMP152 from Australia were identical, respectively.

• Journal of Microbiology
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• 제34권4호
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• pp.295-299
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• 1996

To infer phylogenetic relationships between species of Trichaptum (Polyporaceae), RFLP analyses of PCR-amplified DNAs were accomplished. Regions coding for ITSs of nuclear SSU rRNA genes and for mitochondrial SSU rRNA genes from thirteen strains of four Trichaptum species (T. abietinum, T. biforme, T. fusco-violaceum, and T. laricinum) were amplified and digested with eight restriction enzymes. All the fragmentation patterns were characterized and coded as 0/1 for the absence/presence of fragments. A phylogenetic tree based on the combined data sets was constructed using the Dollo parsimony method. While every two strains of T. abietinum, T. biforme, T. fusco-violaceum, and T. laricinum formed an independent group, the other strains of T. abietimum and T. fusco-violaceum made mixed groupings among compared strains. It is inferred that T. abietinum and T. fusco-violaceum have more variations, possibly geographic or physiological ones, than other species in the genus.

• Journal of Microbiology
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• 제34권1호
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• pp.38-39
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• 1996

The internal regions of nuclear small subunit rRNA from 6 plaeurotus species and 5 Pleurotus ostreatus strains were amplified by PCR and sequenced. The DNA sequences of 8 Pleurotus strains (P. ostreatus NFFA2, NFFA4501, NFFA4001, KFFA4001, KFCC11635, P florida, P. florida, P. sajor-cuju, P. pulmonarius, and P. spodoleucus) were idential, but P. cornucopiae differed from them in two bases out of 605 bases. However, p[hylogenetic analysis of the sequences by DNA-distance matrix and UPGMA methods showed that P. ostreatus NFFA2m1 and NFFA2m2, known as mutants of P. ostreatus NFFA2, belonged to anther group of Basidiomycotina, which is close to the genus Auricularia. The difference of the SSU rDNA sequences of P. cornucopiae from other Pleurotus species tested corresponds to the difference of mitochondrial plasmid type present in Pleurotus species as observed by Kim et al. (1993, Korean J. Microbiol. 31, 141-147).

• Journal of Microbiology
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• 제38권2호
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• pp.62-65
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• 2000

Partial sequence comparisons of mitochondrial small subunit rDNA (mt SSU rDNA) were used to examine taxonomic and evolutionary relationships among seven Penicillium species : two monoverticillate species, two biverticillate species, and three terverticillate species. Amplified fragments of mt SSU rDNA highly varied among seven species in size, suggesting the existence of multiple insertions or deletions in the region. A phylogengtic tree was constructed by exhaustive search of parsimony analysis. The phylogenetic tree distinguished two statistically supported monophyletic groups, one for two monoverticillate species and the other for three terverticillate species and ont biverticillate species, P. vulpinum. The phylogenetic relationship of P. waksmanii, the biverticillate species, was not clear.

• 생명과학회지
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• 제23권10호
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• pp.1260-1266
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• 2013

본 연구에서는 H. marmoreus 3-10균주와 H. marmoreus 1-1균주의 ribosomal DNA (rDNA) cluster의 분석이 수행되었다. Small subunit (SSU)와 intergenic spacer 2 (IGS 2)는 부분적으로 염기서열이 결정되었고, internal transcribed spacer 1 (ITS 1), 5.8S, internal transcribed spacer 2 (ITS 2), large subunit (LSU), intergenic spacer 1 (IGS 1), 5S는 완전하게 염기서열이 결정 되었다. 팽이버섯 H. marmoreus 3-10균주와 H. marmoreus 1-1균주의 rDNA cluster는 총 7,049 bp로 결정되었다. SSU은 1,796 bp, ITS1은 229 bp, 5.8S은 153 bp, ITS2는 223 bp, LSU은 3,348 bp, IGS1은 390 bp, IGS2은 900 bp로 염기서열이 분석되었다. 결정된 rDNA cluster의 총 7,049 bp 중에서 17 bp가 다름이 확인되었고, 각각 SSU (2 bp), ITS (3 bp), LSU (9 bp), IGS (3 bp)에서 차이를 확인하였다. ITS regions의 2차 구조 결과 5개의 stem-loop가 있음이 드러났다. 흥미롭게도, 이들 stem-loop 사이에서 stem-loop V에서 한 개의 상이한 염기가 다른 2차 구조를 나타냄을 확인하였다.