• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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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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• v.3 no.3
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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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• v.25 no.2
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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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• v.24 no.3
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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.

• The Korean Journal of Mycology
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• v.30 no.1
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• pp.23-30
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• 2002

The genetic variations and the rate of mycelial growth in the dikaryon and the monokaryon stages of Pleurotus spp. were surveyed during their subcultures. The highest growth rate was observed on both the 3rd and the 4th subcultures. The remarkably rapid growth rate was detected in P. ostreatus dikaryon. Genetic similarities in the dikaryon and the monokaryon of P. ostreatus were more than 57.5% and 85.7%, respectively, and those of P. eryngii were more than 85.2% and 84.8%, respectively. The genetic similarities of monokaryotic P. ostreatus were higher than those of dikaryotic. The topology of phylogenetic trees showed that the divergence and the clustering patterns of branch did not correlated with the number of subcultures. This suggests that genetic variations occur very randomly on mycelial cultures. These results suggest that the monokaryotic mycelia is genetically more stable than the dikaryotic in subcultures, and that it is very useful to stock monokaryotic mycelia for making spawns and breeding of Pleurotus spp.

• Journal of Life Science
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• v.30 no.12
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• pp.1063-1069
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• 2020

Two crucian carp species (Carassius auratus and C. cuvieri) inhabit Lake Yedang in South Korea, and C. auratus is known to be native to Korea. Classification of these two freshwater fish species is often confused because of their morphological similarity. To distinguish the two species, we conducted phylogenetic and population genetic analyses of C. auratus and C. cuvieri based on their mitochondrial DNA sequences of the cytochrome b gene (CYTB). We also compared our partial CYTB sequence (<1,056 bp) with 10 Chinese, nine Japanese, and two Russian crucian carp fishes. The results of our phylogenetic analysis showed that C. auratus and C. cuvieri were clearly divided into two phylogroups. The nucleotide diversity (π) of C. auratus from Korea, China, and Japan showed a range of 0.146%~0.421%, while the range of π of C. cuvieri from Korea and Japan was lower than those of C. auratus (0.0%~0.054%). Moreover, the comparison of CYTB divergence among crucian carp fishes in China, Japan, and Korea indicated that Korean Carassius fishes were distantly related to those from China and Japan, with two exceptions: the pairwise Fst value between Korean C. auratus and northern Chinese C. auratus was not significantly different. In addition, no significant genetic divergence between Korean and Japanese C. cuvieri was detected. We conclude that, despite the morphological similarities, C. auratus and C. cuvieri should be considered as separate freshwater fish resources in conservation efforts for genetic diversity.

• ALGAE
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• v.32 no.3
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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.