• Journal of Microbiology
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• 제44권6호
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• pp.607-616
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• 2006

Molecular characterization of ten marine cyanobacterial isolates belonging to the order Oscillatoriales was carried out using the phycocyanin locus (cpcBA-IGS) and the 16S-23S internally transcribed spacer region. DNA sequences from the phycocyanin operon discriminated ten genotypes, which corresponded to seven morphotypes identified by traditional microscopic analysis. The cpcB coding region revealed 17% nucleotide variation, while cpcA exhibited 29% variation across the studied species. Phylogenetic analyses support the conclusion that the Phormidium and Leptolyngbya genera are not monophyletic. The nucleotide variations were heterogeneously distributed with no or minimal informative nucleotides. Our results suggest that the discriminatory power of the phycocyanin region varies across the cyanobacterial species and strains. The DNA sequence analysis of the 16S-23S internally transcribed spacer region also supports the polyphyletic nature of the studied oscillatorian cyanobacteria. This study demonstrated that morphologically very similar strains might differ genotypically. Thus, molecular approaches comprising different gene regions in combination with morphological criteria may provide better taxonomical resolution of the order Oscillatoriales.

• Journal of the korean society of oceanography
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• 제39권3호
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• pp.163-171
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• 2004

Sequences of the large subunit ribosomal (LSD) rDNA D1-D2 region of Alexandrium catenella(=A. sp. cf. catenella) and A. tamarense isolates, which were collected along the Korea coasts, were analyzed to understand their phylogenetic relationships and geographical distributions. All A. catenella and A. tamarense isolates belonged to the A. tamarense/catenella/fundyense complex and were grouped with the North American and temperate Asian ribotypes, respectively, regardless of the presence or absence of a ventral pore in the first apical plate. A consistent and peculiar characteristic that differentiated the Alexandrium isolates was amplification of a second PCR product with a lower molecular weight in addition to the predicted one; ten A. catenella isolates belonging to the temperate Asian ribotype yielded this additional PCR product. Sequence alignment revealed that the shorter PCR product resulted from an unusual large deletion of 87 bp in the LSD rDNA D1 domain. The North American and temperate Asian ribotypes were prevalent along the Korean coasts without geographical separation. Given the high genetic homogeneity among widely distributed Alexandrium populations, each ribotype appeared to be pandemic rather than to constitute a distinct regional population.

• 농업과학연구
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• 제41권4호
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• pp.405-413
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• 2014

The evolutionary history of cattle and buffalo has always been a topic of great interest to the evolutionary biologists. The phylogenetic studies of bovin species has been carried out at various levels, varying from the study of domestication and migration of populations to major cladogenesis. Along with the archeological studies there are studies from molecular biology and more recently from genomics. The phylogenetic perspective of the bovins and their evolutionary history, are reviewed in terms of what has been done, what needs to be done and potential challenges in doing it.

• Animal Systematics, Evolution and Diversity
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• 제19권2호
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• pp.297-304
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• 2003

Mitochondrial cytochrome b 유전자를 이용하여 한국에서 채집된 5종을 포함한 올빼미과(Strigidae)의 12속 31종의 계통분석을 하였다. Maximum likelihood 분석과, Kimura two-parameter와 p-distance를 이용하여 유전적 근연 관계를 측정하였다. 본 연구에 이용된 959개의 염기서열 가운데, 459개의 서열에서 변이를 확인하였고, 398개의 서열은 계통학적 정보를 가졌다. 올빼미과는 Clade I (Aegolius) , Clade II (Athene, Micrathene, Glaucidium, Surnia), 그리고 Clade III(Bubo, Nyctea, Pulsatrix, Strix, Otus, Ptilopsis, Ninox) 등 세 개의 그룹으로 나뉘어졌다. 또한 Otus속은 지리적으로 다른 두 개의 그룹으로 분리되는 것이 확인되었다.

• 한국수산과학회지
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• 제47권1호
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• pp.72-78
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• 2014

We investigated the molecular phylogeny and genetic differences among local populations of Korean Hemiculter fishes based on their mitochondrial cytochrome b gene sequences. Our results indicated that Hemiculter leucisculus populations in China were clearly divided into two groups. The first group (Group 1) included the populations of the Yangtze River and its surrounding areas (including the Qiantangjiang, Lingjiang, Jiulongjiang, and Minjiang rivers); the second group (Group 2) contained local populations from southern China (including the Nanliujiang, Zhujiang, Wanquanhe, Qianjiang, and Nandujiang rivers). The Korean Hemiculter eigenmanni differed in its cytochrome b gene sequence by 0.6-1.0% from the Chinese H. leucisculus (Group 1), which inhabited the Yangtze River and its surrounding areas, suggesting they were phylogenetically close and likely to be the same species. The Korean H. leucisculus differed from the Chinese H. leucisculus (both Groups 1 and 2) by 8.1-9.5%, indicating a very distant phylogenetic relationship; however, the Korean H. leucisculus differed from Hemiculter bleekeri by only 0.5-0.7%, showing intraspecific nucleotide differences. We conclude that the taxonomic relationship between the Korean H. leucisculus and H. bleekeri requires further investigation using type specimens.

• Journal of Microbiology and Biotechnology
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• 제24권10호
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• pp.1301-1307
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• 2014

White-rot fungi of the genus Bjerkandera are cosmopolitan and have shown potential for industrial application and bioremediation. When distinguishing morphological characters are no longer present (e.g., cultures or dried specimen fragments), characterizing true sequences of Bjerkandera is crucial for accurate identification and application of the species. To build a framework for molecular identification of Bjerkandera, we carefully identified specimens of B. adusta and B. fumosa from Korea based on morphological characters, followed by sequencing the internal transcribed spacer region and 28S nuclear ribosomal large subunit. The phylogenetic analysis of Korean Bjerkandera specimens showed clear genetic differentiation between the two species. Using this phylogeny as a framework, we examined the identification accuracy of sequences available in GenBank. Analyses revealed that many Bjerkandera sequences in the database are either misidentified or unidentified. This study provides robust reference sequences for sequence-based identification of Bjerkandera, and further demonstrates the presence and dangers of incorrect sequences in GenBank.

• The Plant Pathology Journal
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• 제36권4호
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• pp.364-377
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• 2020

Sugarcane is an important sugar crop contributes more than 80% of world sugar production. Mosaic, leaf fleck, and yellow leaf (YL) are the major viral diseases affecting sugarcane, amongst YL occurrence is widely reported in all the sugarcane growing countries. It is caused by Sugarcane yellow leaf virus (SCYLV) and detailed works were done on complete genome characterization, transmission, and management. However, in countries like Egypt, South Africa, Cuba, Mauritius and Hawaii, the disease was reported to the cause of sugarcane yellow leaf phytoplasma (SCYP) and/or SCYLV as single/combined infections. Hence, we have investigated in detail to identify the exact Candidatus phytoplasma taxon associated in Indian cultivars affected with YL. The sequencing results and the restriction fragment length polymorphism pattern of the PCR products using the universal phytoplasma primers confirmed presence of sugarcane grassy shoot (SCGS) phytoplasma (16SrXI group) in the YL-affected plants. Mixed infection of SCYLV and SCGS phytoplasma was estimated as 32.8% in YL affected plants. Evolutionary genetic relationship between SCYP and SCGS phytoplasma representatively taken from different countries showed that SCYP from South Africa and Cuba were diverged from others and had a highest similarity with SCGS phytoplasma. Although we wanted to identify SCYP from YL affected Indian sugarcane cultivars, the study clearly indicated a clear absence of SCYP in YL affected plants and we found SCYLV as the primary cause for the disease.

• Asian-Australasian Journal of Animal Sciences
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• 제5권1호
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• pp.173-181
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• 1992

Duck is an important domestic animal, especially in Asia. Eighty five percent of ducks in the world are kept in Asia, especially in the East and South Asia regions. The ancestor of domesticated ducks was mallard (Anas platylhynchos), which are still migrating between north and southern parts in Eurasia. Ducks have been domesticated in China for at least 3000 years ago. Phylogenetic studies on ducks, employing electrophoresis of blood proteins, indicate a marked difference of genetic constitution between duck breeds in southeast Asia and those in northeast Asia. Duck embryonic ovary is much more active in secretion of sex steroid hormones especially estradiol than the embryonic testes. Estradiol secreted by the embryonic left ovary has an important role in female sexual differentiation in ducks. In the female ducks, plasma LH, estradiol and testosterone levels increase and reach peaks shortly before the first egg, while progesterone level reach a peak shortly after the first egg. In laying ducks oviposition mostly occurs in the last 3 hr of darkness and first hr of light ranging 02:00-06:00 under 14 hr light (05:00-19:00) and 10 hr darkness photoperiodic condition. Measurements of plasma hormone levels reveal that onset of darkness is a major signal for LH release from the pituitary and the subsequent release of progesterone from ovary, and for induction of ovulation in the female duck.

• 한국동물학회지
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• 제34권1호
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• pp.110-122
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• 1991

기름종개과의 N. toni, L. costota, N. multifasciata 3종에 대한 형태분석, 핵형분석 및 전기영동법에 의한 유전자 분석을 실시 각 종의 지리적 변이 및 계통적 유연관계를 조사하였다. 형태 측정치에 대한 discriminant 분석결과 연 yoni 월악산집단, 1. costoto 거제도집단 그리고 환multifasc지물 산철집단이 같은 종내 타 집단들과 형태상 완전히 분리 되어졌다. 핵형분석에서 N. muftifosciota와 1. costoto는 2n: 50으로 염색체수는 조사된 전 집단이 변리없이 동일하였다. N to티 삼척과 진부집단은 2n: 50으로 동일하였으나 고성집단은 2n=50, In : 48인 염색체상이 한개체에서 동시에 발견되었고, 인형성부위의 위치 및 형태가 타 집단과 차이가 있었다. 전기영동을 실시하여 총 28개의 유전자를 검출, 분석하였다. 3종중 N. multifosciata 청도집단의 유전적 변이 (HDi 123, HG : .160)가 가장 높았고, N. toni 고성집단이 가장 적었다. ( HD= .017, HG= .015). N. yoni 고성집단과 강릉집단은 각 집단의 고유한 genetic marker를 다수 갖고 있으며 타집단들과 유전적 근연관계도 매우 먼 것으로 나타나 각기 독립된 별종으로 추정된다.

• Mycobiology
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• 제45권4호
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• pp.263-269
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• 2017

The genus Peronospora, an obligate biotrophic group belonging to Oomycota, causes serious damage to a variety of wild and ornamental plants, as well as cultivated crops, such as beet, rose, spinach, and tobacco. To investigate the diversity of Peronospora species parasitic to Stellaria and Pseudostellaria (Caryophyllaceae) plants in Korea, we performed a morphological analysis on dried herbarium specimens and molecular phylogenetic inferences based on internal transcribed spacer rDNA and cox2 mitochondrial DNA sequences. As a result, it was confirmed that there are four species of Peronospora parasitic to specific species of Stellaria and Pseudostellaria, all of which were hitherto unrecorded in Korea: P. alsinearum (ex Stellaria media), P. stellariae-aquaticae (ex Stellaria aquatica), P. stellariae-uliginosae (ex Stellaria alsine), and P. pseudostellariae (ex Pseudostellaria palibiniana). In addition, Peronospora specimens parasitic to Pseudostellaria davidii differed morphologically from P. pseudostellariae owing to the large and ellipsoidal conidia; this morphological discrepancy was also validated by the high genetic divergence between the two species. Peronospora casparyi sp. nov. is described and illustrated here.