• Parasites, Hosts and Diseases
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• 제23권2호
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• pp.305-312
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• 1985

Ixodes persulcatus 진드기의 표면구조 관찰을 위하여 교미중에 있는 자웅 성충 표본을 주사전자현미경으로 사진을 촬영하여 영상을 분석하였으며 아울러 생태와 질병과의 관련성에 대하여 문헌고찰을 하였던 바, 다음과 같은 결과를 얻었다. 1. 자웅표본간에 성별에 따른 외형상의 차이가 명백하였으며 자충은 웅충에 비하여 대형의 모습을 나타냈다. 2. 생식구는 깊게 잘 발달되어 있으며, 항문구는 항문주변의 전방으로 명확하고 특징적인 구조를 나타냈다. 3. 제4촉지는 단축되어 있는 형태를 나타내며, 제3촉지의 복방상부에 얹혀져 있었다. 치열에 대한 치식은 일반적으로 3/3을 나타냈다. 4. 웅충에 있어서의 악체부의 배면후방바닥은 반듯한 직선장을 나타냈다. 5. 각종 전염병과 철새와의 관련성에 있어서 동 진드기유는 매개체로서 작용하며 역학상 중요성이 있는 것으로 고찰되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제12권1호
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• pp.15-21
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• 1999

The aim of the present study was to determine the effect of paternal sex chromosome on early development of buffalo embryos fertilized and cultured in vitro. Embryos were produced in vitro from abattoir derived buffalo oocytes. The cleaved embryos were cocultured with buffalo oviductal epithelial cells and evaluated on day 7 under the phase contrast microscope to classify development. The embryos which reached the morula/blastocyst stage were fast developing, the embryos which were at 16-32 cell stage were medium developing and the embryos below 16 cell stage were slow developing. The embryos which showed some fragmentation in the blastomeres or degenerated blastomeres, were degenerating. Sex of emberyos (n=159) was determined using PCR for amplification of a male specific BRY. 1 (301 bp) and a buffalo specific satellite DNA (216 bp) fragments. The results thus obtained show that 1) X and Y chromosome bearing sperms fertilize oocytes to give almost equal numbers of cleaved XX and XY embryos, 2) male embryos develop faster than female embryos to reach advanced stage and 3) degeneration of buffalo embryos is not linked with the paternal sex chromosome. We suggest that faster development of males is due to differential processing of X and Y chromosome within the zygote for its activation and / or differential expression of genes on paternal sex chromosome sex chromosome during development of buffalo embryos fertilized and cultured in vitro which may be attributed to a combination of genetic and environmental factors.

• 한국어류학회지
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• 제1권1_2호
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• pp.64-72
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• 1989

한국산(韓國産) 퉁가리속(屬) 어류(魚類) 3 종(種)의 7 집단(集團)에 대해서 염색체(染色體)를 분석하였다. 염색체 수와 핵형(核型)은 종(種) 간(間)에 그 차이가 뚜렷하여 Liobagrus andersoni는 2n=28(AN=56)이었고, 9쌍의 metacentric 염색체와 5쌍의 submetacentric 염색체로 구성되어 있었으며, L. mediadiposalis는 2n=42(AN=84)로, 14쌍의 metacentric 염색체와 7쌍의 submetacentric 염색체로 나타났다. L. obesus의 경우는 염색체 수가 2n=20(AN=40)이고 모두 metacentric염색체로 구성되어 있어 이제까지 보고된 메기목(目) 어류 중 가장 적은 2n값을 보였다. 성적이형현상(性的二型現象)이나 집단간의 염색체 다형현상(多型現象)은 볼 수 없었다. 이상의 결과로 미루어 Robertsonian rearrangement를 위시한 pericentric inversion과 같은 염색체 재배열(再排列)이 종분화(種分化)의 중요한 요인이 되었음을 암시(暗示)하는 것으로 생각되었다.

• Journal of Microbiology and Biotechnology
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• 제18권9호
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• pp.1522-1528
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• 2008

The morphogenetic behavior of a tropical marine Yarrowia lipolytica strain on hydrophobic substrates was studied. Media containing coconut oil or palm kernel oil (rich in lauric and myristic acids) prepared in distilled water or seawater at a neutral pH supported 95% of the cells to undergo a transition from the yeast form to the mycelium form. With potassium laurate, 51 % of the cells were in the mycelium form, whereas with myristate, 32% were in the mycelium form. However, combinations of these two fatty acids in proportions that are present in coconut oil or palm kernel oil enhanced the mycelium formation to 65%. The culture also produced extracellular lipases during the morphogenetic change. The yeast cells were found to attach to the large droplets of the hydrophobic substrates during the transition, while the mycelia were associated with the aqueous phase. The alkane-grown yeast partitioned more efficiently in the hydrophobic phases when compared with the coconut oil-grown mycelia. A fatty acid analysis of the mycelial form revealed the presence of lauric acid in addition to the long-chain saturated and unsaturated fatty acids observed in the yeast form. The mycelia underwent a rapid transition to the yeast form with n-dodecane, a medium-chain aliphatic hydrocarbon. Thus, the fungus displayed a differential behavior towards the two types of saturated hydrophobic substrates.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1482-1484
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• 2008

Spherical silver nanoparticles (nano-Ag) were synthesized and their antifungal effects on fungal pathogens of the skin were investigated. Nano-Ag showed potent activity against clinical isolates and ATCC strains of Trichophyton mentagrophytes and Candida species ($IC_{80}$, 1-7${\mu}g/ml$). The activity of nano-Ag was comparable to that of amphotericin B, but superior to that of fluconazole (amphotericin B $IC_{80}$, 1-5${\mu}g/ml$; fluconazole $IC_{80}$, 10-30${\mu}g/ml$). Additionally, we investigated their effects on the dimorphism of Candida albicans. The results showed nano-Ag exerted activity on the mycelia. Thus, the present study indicates nano-Ag may have considerable antifungal activity, deserving further investigation for clinical applications.

• Journal of Microbiology and Biotechnology
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• 제17권11호
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• pp.1797-1804
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• 2007

Lycopene, an acyclic carotenoid found in tomatoes (Lycopersicon esculentum) and a number off fruits, has shown various biological properties, but its antifungal effects remain poorly understood. The current study investigated the antifungal activity of lycopene and its mode of action. Lycopene showed potent antifungal effects toward pathogenic fungi, tested in an energy-independent manner, with low hemolytic effects against human erythrocytes. To confirm the antifungal effects of lycopene, its effects on the dimorphism of Candida albicans induced by fetal bovine serum (FBS), which plays a key role in the pathogenesis of a host invasion, were investigated. The results showed that lycopene exerted potent antifungal activity on the serum-induced mycelia of C. albicans. To understand the antifungal mode of action of lycopene, the action of lycopene against fungal cell membranes was examined by FACScan analysis and glucose and trehalose-release test. The results indicated that lycopene caused significant membrane damage and inhibited the normal budding process, resulting from the destruction of membrane integrity. The present study indicates that lycopene has considerable antifungal activity, deserving further investigation for clinical applications.

• 한국어류학회지
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• 제28권3호
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• pp.175-178
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• 2016

전라북도 남원시 식정동에서 채집한 한국 고유종인 섬진자가사리를 암, 수 각각 9마리와 8마리의 핵형 분석을 실시하였다. 섬진자가사리의 염색체 수는 2n=42로 조사되었고, 핵형은 28 metacentric과 14 submetacentric으로 이루어져 있었으며 FN은 80이었다. 이번 결과에서 배수체와 암수 간의 성적이형은 발견되지 않았다. 섬진자가사리는 근연종들과 염색체 수는 같았으나, 핵형에서는 차이를 보였다.

• 대한치과교정학회지
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• 제20권2호
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• pp.391-407
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• 1990

This study was performed to establish the cephalometric standards and to observe the nature of anatomic fit in the internal structural relationship of the craniofaciodental complex of the normal Korean by means of Moyers' method. Lateral cephalograms of 143 males and 144 females with normal occlusion and acceptable profile from 6 to 25 years of age, which were consisted of 5 groups that were 6 year-, 9 year-, 12 year-, 15 year- and adult-group were obtained. Data were gathered by traced digitizing the cephalograms and were statistically analyzed. The findings can be summerized as follows. 1. Norms of Korean males, females and both sexes in each group were established. 2. There was little significant sexual dimorphism in the form of craniofacial skeleton of all age groups. 3. The height and length of craniofacial skeleton was alike in each sexes in the 6 year-, 9 year- and 12 year-group, whereas it was larger in male than in female in the 15 year- and adult-group. 4. There were no significant sexual differences in the internal structural relationship of the craniofacial skeleton in all age groups.

• 환경생물
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• 제38권3호
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• pp.350-354
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• 2020

Many parrots are considered endangered species due to threats from human activities. Gender determination is of great importance for biological studies and the conservation of endangered parrots. However, like other birds, gender determination in parrots is hindered due to the lack of external dimorphism between males and females. A molecular approach using the chromo-helicase-DNA binding protein 1 (CHD1) gene is commonly used for sexing birds. This study aimed to determine the gender of parrots from Korean zoos based on amplification and visualization of the partial CHD1 gene. The samples of 13 parrot species were collected from three different zoos in Korea and the extracted DNA templates were amplified using CHD1 gene primers. The gender of 27 samples of 13 species was determined by visualizing the PCR products on an agarose gel. While male parrots were indicated by a single band, female parrots were indicated by double bands. The findings provide additional information, which might be helpful for the management and care of parrots in Korean zoos.

• Animal cells and systems
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• 제14권4호
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• pp.351-360
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• 2010

A new species of the Cletopsyllidae belonging to the genus Isocletopsyllus Huys and Lee, 1999 is described from the materials collected from subtidal sandy bottoms at Jeju Island and Ulleung Island, Korea. So far, only two species of the genus Isocletopsyllus, viz. I. tertius (Por, 1964) from Israel and I. quartus (Soyer, 1966) from Banyuls-sur-Mer (France) are recorded, both from the Mediterranean Ocean. The new species can be clearly distinguished from its congeners by the combination of the following characters: (1) female antennule with a large process on the outer margin of first segment, (2) caudal rami with a bulbous proximal inner expansion, and shorter than those of other species (about four times long as wide in the new species), (3) second segment of P1 exopod with a short rod-like inner seta, (4) sexual dimorphism presented in the second endopodal segment of male P2, not in exopod of P4, and (6) female P5 with a very long exopod with very short second outer seta. A table comparing the modifications of swimming legs in the family Cletopsyllidae Huys and Lee, 1999 is presented. This is the first record of this family from Korea.