• Asian-Australasian Journal of Animal Sciences
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• 제16권3호
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• pp.315-319
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• 2003

Random amplified polymorphic DNA (RAPD) analysis was done with 19 oligonucleotide primers to study genetic similarities and divergence among different types of Deoni breed of cattle viz., Balankya, Wannera and Waghya. Six random primers produced low to high numbers of polymorphic bands between pooled DNA of different Deoni types. Of the 48 RAPD markers obtained 33 were common to all Deoni types, 3 were individual specific and 12 were polymorphic for different Deoni types. The mean average percentage difference values among Deoni types showed that Balankya and Wannera had less genetic divergence when compared to Waghya.

• Animal cells and systems
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• 제3권3호
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• pp.303-309
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• 1999

Inter- and intraspecific genetic relationships between Rana amurensis from Korea and Russia and other brown frogs were investigated by nucleotide sequence of a 504 base pair (bp) fragment of the mitochondrial cytochrome b gene. Nucleotide sequence similarities among Korean populations of R. amurensis ranged from 99.6% to 97.6% and 98.8% within Russian populations. The nucleotide sequence similarity between Korean and Russian R. amurensis ranged from 86.9% to 85.5%. Based on Kimura-2-parameter distance, the sequence divergence between R. amurensis from Korea and Russia was 16.18% and 18.04% among other related brown frogs. interspecific sequence divergences among R. amurensis and other related brown frogs diverged by 20.3%. Using an estimate of 2-4% mitochondrial DNA sequence divergence per million years, Korean and Russian R. amurensis diverged about 8 to 4 million years ago (Mya) and other brown frogs diverged about 9 to 5 Mya from ancestral frogs and distributed from North Asia to Sakhalin in a short time. In the neighbor-joining and UPGMA tree R. amurensis was clustered into two groups with Korean and Russian populations and the other brown frogs were grouped separately with diverged trichotomous clusters (R. dybowskii and R. pirica, R. okinavana and R. tsushimensis, and R. japonica and R. longicrus).

• 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.

• ALGAE
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• 제24권3호
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• pp.129-138
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• 2009

DNA-based discrimination of species is a powerful way for morphologically otherwise similar species, like centric diatoms. Here, the author sequenced long-range nuclear ribosomal DNAs, spanning from the 18S to the D5 region of the 28S rDNA, of Stephanodiscus, particularly including a Korean isolate. By comparisons, high DNA similarities were detected from the rDNAs of nine Stephanodiscus (>99.4% in 18S rDNA, >98.0% in 28S rDNA). Their genetic distances, however, were significantly different (Kruskal-Wallis test, p < 0.01) compared to two related genera, namely Cyclotella and Discostella. In addition, genetic distances of 18S rDNAs were significantly different (Student’s t-test, p = 0.000) against those of the 28S rDNAs according to individual genera (Cyclotella, Discostella, and Stephanodiscus). Phylogenetic analyses showed that Stephanodiscus and Discostella showed a sister taxon relationship, and their clade was separated from a cluster of Cyclotella (1.00 PP, 100% BP). This suggests that Stephanodiscus has highly conserved sequences of both 18S and 28S rDNA; however, Stephanodiscus is well-separated from other freshwater centric diatoms, such as Cyclotella and Discostella, at the generic level.

• 한국균학회지
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• 제30권1호
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• pp.23-30
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• 2002

본 연구의 목적은 느타리버섯과 큰느타리버섯의 균사체 계대배양에 따른 유전적 변이 양상을 조사하고, 각각의 이핵체와 단핵체를 RAPD 방법으로 계대배양 횟수에 따른 변이를 조사하는 것이다. 또한, 유전적 변이와 생장력과의 관계를 추적하기 위하여 계대배양 횟수 및 종에 따른 생장력을 조사하였다. 그 결과, 균사생장력은 대체적으로 3회와 4회째 계대배양 때의 생장속도가 가장 빨랐으며, 5회째 이상부터는 감소하였다. 느타리버섯 이핵체는 가장 빠른 생장속도를 보였으며, 느타리버섯 단핵체와 큰느타리버섯 이핵체, 단핵체는 거의 비슷한 속도로 생장하였다. 또한, 느타리버섯의 이핵체와 큰느타리버섯 이핵체 간의 생장속도는 동일한 조건에서 약4배의 차이기 났다. 유사성 조사에서는 느타리버섯 이핵체는 57.5%, 단핵체 85.7%, 큰느타리버섯 이핵체는 71.8%, 단핵체 72.2% 이상의 유사성을 나타내었다. 균주의 변이는 생장속도와 균주의 type과 관계가 있는 것으로 생각된다. 생장속도가 빠른 균주가 느린 균주보다 변이가 많이 나타난다는 것을 알 수 있었으며, 이핵균주보다는 단핵균주가 유전적으로 안전한 것으로 판단된다. 그러나, phylogenetic tree에서는 종, 균주 type, 균주 생장속도 및 계대배양 횟수와는 무관하게 branch가 분기되고, grouping 되었다. 결론적으로, 균사체의 많은 계대배양은 생장속도를 저하시키고, 유전적 변이를 야기시키는 요인으로 작용하며, 동일한 조건의 배양에서 이핵균주로 배양 보존하는 것보다는 단핵균주로 배양 보존하는 것이 종균제조와 육종에 유리한 것으로 사료된다.

• 생명과학회지
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• 제30권12호
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• pp.1063-1069
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• 2020

본 연구는 형태학적으로는 식별이 어려운 재래종인 붕어(Carassius auratus)와 일본 도입종인 떡붕어(C. cuvieri)의 분자 수준에서 유전적 차이와 계통 유연관계를 규명하기 위해 수행되었다. 이를 위해 충남 예당호에서 서식하고 있는 두 붕어종을 포획하여 DNA를 각각 분리한 CYTB 유전자 서열을 결정하여 비교 분석 하였으며, NCBI Genbank 데이터베이스에서 확보 가능한 중국, 일본, 러시아의 붕어속 담수어와도 유전적 차이와 계통 유연관계를 조사하였다. 붕어와 떡붕어가 계통분류학적인 위치에서 각각 차이나는 phylogroup을 형성하였다. 집단 내 염기서열 다양성은 떡붕어가 붕어보다 낮은 수준을 보였고 집단 간 유전적 차이는 중국 북부 붕어와 한국 붕어 간에 유의적 차이를 검출 할 수 없었는데, 이는 두 집단이 공통조상으로 비롯된 것으로 추측 해 볼 수 있다. 일본 떡붕어와 한국 떡붕어 간에 집단 간 유의적인 유전적 차이가 검출 되지 않았는데 이는 1970년대 일본 떡붕어가 국내 담수계에 인위적으로 도입되어 현재까지 서식하기 때문으로 사료된다. 이 두 경우를 제외하고는 중국, 한국, 일본에 서식하고 있는 붕어속 집단 간에 유의적 유전적 차이가 검출되었다. 본 연구의 결과는 붕어와 떡붕어가 형태학적으로는 유사하지만 유전적으로는 유의적 차이가 있는 별개의 담수어 자원으로서 구별되며, 유전적 다양성의 유지 및 보존을 위한 과학적 근거로서 활용 될 수 있을 것으로 생각된다.

• ALGAE
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• 제32권3호
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• pp.171-179
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• 2017

The strictly freshwater red algal order Batrachospermales has undergone numerous taxonomic rearrangements in the recent past to rectify the paraphyly of its largest genus Batrachospermum. These systematic investigations have led to the description of new genera and species as well as re-circumscription of some taxa. Specimens collected from two locations in the southeastern USA were initially identified as being allied to Batrachospermum sensu lato, but could not be assigned to any recognized species. Representative rbcL (plastid) and COI-5P (mitochondrion) sequences showed these specimens to be similar to each other and not closely matching the previously published sequence data for other Batrachospermum taxa. Comparison of sequence variation and morphology with a broader range of batrachospermalean taxa resulted in the proposal of a new monotypic genus Lympha mucosa gen. et sp. nov. to accommodate these specimens. Lympha mucosa is sister to members of a newly described genus Volatus, but the two genera are easily distinguished based on straight versus curved, twisted or spirally coiled carpogonial branch, respectively. This new taxon has morphological similarities to Batrachospermum sections Turfosa and Virescentia, but can be differentiated based on genetic divergence in rbcL and COI-5P as well as a combination of morphological characters: dense, compressed whorls, axial carposporophytes with a single type of gonimoblast filament; cortication of the main axis closely appressed; and short, straight carpogonial branch arising from the pericentral cell and carpogonia with unstalked, lanceolate trichogynes. This new taxon adds to the freshwater red algal diversity of the southeastern USA, a region already known for biodiversity and high endemism of the aquatic flora and fauna. It is also a relevant new addition to the taxonomic knowledge of the freshwater red algal Batrachospermales.