• Korean Journal of Ichthyology
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• v.5 no.2
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• pp.226-234
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• 1993

Cobitis sinensis-longicorpus complex considered as hybrid origin between C. sinensis and C. longicorpus coccurred ommonly in the upper streams of the Nakdong River, Korea. Histological examinations of their gonad were accompanied with 272 individuals of C. sinensis-longicorpus complex collected. Most of fishes collected were females, however, only 6 individuals were found males. The ovarian tissues of females are completely fertile undergoing normal oogenensis. In the male gonads, testicular lobule structure with abnormal vacuolar tissues were observed. Spermatogonia and spermatocytes were also observed of their testis however spermatids or sperms were not shown in their developmental stages. From these facts, we infer that female population of C. sinensis-longicorpus complex may be unique reproductive hierarchy accomplishing their reproduction with participation of males of their closely related bisexual species.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.6
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• pp.789-793
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• 2008

The gayal (Bos frontalis) in China is a very rare semi-wild and semi-domestic bovine species. There still exist remarkable divergences on the gayal's origin and taxonomic status. In the present study, the cytochrome b (Cyt b) gene entire sequences (1,140 bp) of 11 gayals in Yunnan China were analyzed. Combined with other bovine Cyt b sequences cited in GenBank, the phylogenetic trees of genus Bos were reconstructed by neighbor-joining (NJ) and maximum parsimony (MP) methods with Bubalus bubalis as outgroup. Sequence analysis showed that, among 1,140 sites compared for 11 gayals, 95 variable sites (8.33% of all sites) and 6 different haplotypes were observed, showing abundant mitochondrial genetic diversity in gayals. Both NJ and MP trees demonstrated that gayals in this study were markedly divided into three embranchments: one embranchment clustering with Bos gaurus, another clustering with Bos taurus, and the third clustering with Bos indicus. The result of phylogenetic analysis suggested that the gayal might be the domesticated form of the gaur, and a great proportion of the gayal bloodline in China was invaded by other bovine species.

• Mycobiology
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• v.29 no.1
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• pp.1-6
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• 2001

Nine species of genus Ganoderma collected in Korea and abroad including Ganoderma lucidum complex and G. lucidum were compared by investigating growth characteristics. In the bottle culture, the mycelial growth periods of G. lucidum from Taiwan and North America was 26 to 30 days compared to that of Korean G. lucidum, which was 30 to 32 days. Cultivation period of Taiwan and North American isolates was 30 to 32 days which were 11 to 17 days shorter than those of Korean isolates. Biological efficiency of Taiwan and North American isolates were ranged from 3.3 to 5.5%, which were apparently lower than that of Korean isolates which ranged from 6.2 to 9.4%. Korean isolates had longer stipes($15{\sim}40$ mm) and more number of pileus($4{\sim}6$/bottle) than those of Taiwan and North American isolates. The G. lucidum isolates collected from Korea will be regarded as the independent species from the G. lucidum collected from Taiwan and North America since, the G. lucidum from Korea showed much different growth characteristics in various aspects compared to the G. lucidum from Taiwan and North America.

• Parasites, Hosts and Diseases
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• v.50 no.2
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• pp.137-141
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• 2012

From 2006 to 2010, hospitals in Hanoi treated 10 human patients for dirofilariasis. The worms were collected from parasitic places, and identification of the species was completed by morphology and molecular methods. Ten parasites were recovered either from the conjunctiva (n=9) or subcutaneous tissue (n=1). The parasites were 4.0-12.5 cm in length and 0.5-0.6 mm in width. Morphological observations suggested all parasites as Dirofilaria repens. Three of the 10 parasites (1 from subcutaneous tissue and 2 from eyes) were used for molecular confirmation of the species identification. A portion of the mitochondrial cox1 (461 bp) was amplified and sequenced. Nucleotide and amino acid homologies were 95% and 99-100%, respectively, when compared with D. repens (Italian origin, GenBank AJ271614; DQ358814). This is the first report of eye dirofilariasis and the second report of subcutaneous tissue dirofilariasis due to D. repens in Vietnam.

• Korean Journal of Ichthyology
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• v.28 no.1
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• pp.47-51
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• 2016

Three specimens of Abudefduf septemfasciatus were collected firstly from tidal pools on the southern and northern coasts of Jeju Island, Korea in August 2015. This species is characterized by black blotches on the upper origin of the pectoral fin, upper caudal peduncle and a dorsal fin between the second and fourth spines, predorsal scales beyond to above the middle of the eye, 12~13 soft dorsal and anal fin rays, and 20 lateral-line scales. This species is distinguishable from Abudefduf sordidus by soft dorsal and anal fin rays, location of caudal peduncle blotch, and location of the dorsal fin blotch. The newly proposed Korean name is "Il-gop-jul-ja-dom".

• Animal cells and systems
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• v.3 no.1
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• pp.1-7
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• 1999

Gonadotropin-releasing hormone (GnRH) was originally isolated as a hypothalamic peptide that regulates reproduction by stimulating the release of gonadotropins. Using comparative animal models has led to the discovery that GnRH has a more ancient evolutionary origin. Durinq evolution GnRH peptide underwent gene duplication and structural changes to give rise to multiple molecular forms of GnRHs. Mammalian GnRH initially considered to be the sole molecular form, is now grouped as a family of peptides along with GnRH variants determined from representatives in all classes of vertebrates. Vertebrate species including primates and humanshave more than one GnRH variant in individual brains; a unique GnRH form in the forebrain and chicken IIGnRH in the midbrain. Furthermore, several species of bony fish have three molecular variants of GnRH: salmon GnRH sea-bream GnRH and chicken II GnRH. Also, it has been shown that in addition to the olfactory placodes and the midbrain, there is a third embryonic source of GnRH neurons from the basal diencephalon in birds and fish, which might be true for other vertebrates. Therefore, comparative animal models like fish with discrete sites of expression of three molecular variants of GnRH in individual brains, could provide insight into novel functions of GnRH variants, conservation of gene regulation, and mechanisms governing reproduction in vertebrates.

• Journal of Plant Biotechnology
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• v.38 no.3
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• pp.234-240
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• 2011

The genus Paeonia belongs to the family Paeoniaceae having significant medicinal and ornamental importance. The present investigation was undertaken with an aim to understand phylogenetic relationships of three Paeonia species (P. lactiflora, P. obovata, and P. suffruticosa) that are widely distributed in China, Korea, and Japan, using nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) sequence and to compare the phylogeny results with investigations reported earlier using existed sequences of the same species. The size variation obtained among sequenced nrDNA ITS region was narrow and ranged from 722 to 726 bp. The highest interspecific genetic distance (GD) was found between P. lactiflora and P. suffruticosa or P. obovata. The phylogram obtained using our nrDNA ITS sequences showed non-congruence with previous hypothesis of the phylogeny between section Paeonia and section Moutan of genus Paeonia. This result was supported by the phylogenetic relations showed in the phylogram constructed with existed sequences in NCBI. The present study suggested that P. obovata belonging to section Paeonia was phylogenetically closer to P. suffruticosa representing section Moutan of genus Paeonia than P. lactiflora belonging to section Paeonia. The main reason of the paraphyly of section Paeonia is thought to be nucleotide additivity directly caused by origin hybridization. This study provides more sequence sources of genus Paeonia, and will help for further studies in intraspecies population, and their phylogentic analysis and molecular evolution.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.307-310
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• 2009

A specimen (862.3 mm standard length) of Pisodonophis cancrivorus (Richardson, 1848), family Ophichthidae, was first collected from the coast of Uljin-gun in Gyeongsangbuk-do, Korea in September 2008. This species is characterized by the following: fleshy protrusions of upper jaw in the front and rear of the posterior nostril, 3~5 irregular rows of granular teeth in bands on maxilla, mandible and vomer, and origin of dorsal fin above the middle of the pectoral fin. Based on the fleshy protrusions found on its upper jaw, a new Korean name "dol-gi-ba-da-baem" has been proposed for this species.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.12
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• pp.1688-1695
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• 2016

The maternally inherited mitochondrial DNA (mtDNA) D-loop region is widely used for exploring genetic relationships and for investigating the origin of various animal species. Currently, domestic ducks play an important role in animal protein supply. In this study, partial mtDNA D-loop sequences were obtained from 145 samples belonging to six South-East Asian duck populations and commercial duck population. All these populations were closely related to the mallard duck (Anas platyrhynchos), as indicated by their mean overall genetic distance. Sixteen nucleotide substitutions were identified in sequence analyses allowing the distinction of 28 haplotypes. Around 42.76% of the duck sequences were classified as Hap_02, which completely matched with Anas platyrhynchos duck species. The neighbor-joining phylogenetic tree also revealed that South-East Asian duck populations were closely related to Anas platyrhynchos. Network profiles were also traced using the 28 haplotypes. Overall, results showed that those duck populations D-loop haplotypes were shared between several duck breeds from Korea and Bangladesh sub continental regions. Therefore, these results confirmed that South-East Asian domestic duck populations have been domesticated from Anas platyrhynchos duck as the maternal origins.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.4
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• pp.371-381
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• 2004

Numerical simulation of $CO_2$ addition effects to fuel and oxidizer streams on flame structure has been conducted with detailed chemistry in H$_2$-O$_2$ diffusion flames of a counterflow configuration. An artificial species, which displaces added $CO_2$ in the fuel- and oxidizer-sides and has the same thermochemical, transport, and radiation properties to that of added $CO_2$, is introduced to extract pure chemical effects in flame structure. Chemical effects due to thermal dissociation of added $CO_2$ causes the reduction flame temperature in addition to some thermal effects. The reason why flame temperature due to chemical effects is larger in cases of $CO_2$ addition to oxidizer stream is well explained though a defined characteristic strain rate. The produced CO is responsible for the reaction, $CO_2$＋H=CO＋OH and takes its origin from chemical effects due to thermal dissociation. It is also found that the behavior of produced CO mole fraction is closely related to added $CO_2$ mole fraction, maximum H mole fraction and its position, and maximum flame temperature and its position.