• 대한의생명과학회지
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• 제6권3호
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• pp.165-170
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• 2000

Vacuolar (H$^{+}$)-ATPase (V-ATPase)는 multi-subunit로 구성된 단백질로서, proton pumping을 통해 세포내 산성화반응에 관여를 한다. 최근에 이 단백질이 synaptic vesicle에서도 발견된 것으로 보아 뇌 신경전달에 중요한 역할을 수행할 것으로 추정하고 있다. 우리는 흰쥐 뇌에서 분리한 mRNA를 주형으로 한 PCR 반응에서 16 kDa subunit의 V-ATPase cDHA를 클로닝할 수 있었고, 이의 염기서열 또한 결정하였다. 분리된 뇌 16 kDa V-ATPase의 coding sequence는 전체 468 bp로서 간에서 보고되었던 것과 동일한 크기였다. 단지 3' 말단의 염기 하나가 A에서 C로 바뀌어 있었는데 모두 alanine (GCA, GCC)을 지정하기 때문에 단백질의 일차구조에는 변화가 없는 것으로 확인되었다. 한편 rat brain cDNA library에서도 동일한 clone이 분리되었는데 역시 같은 부분에서 polymorphism이 발견되었고, RNA splicing 등 더 이상의 조직특이적 변화는 없었다. 본 연구는 16 kDa V-ATPase의 뇌에서의 기능과 신경말단에서의 neurotransmission 및 synaptic vesicle의 재순환 기전을 이해하는데 유용한 정보가 될 것이다.

• 식물조직배양학회지
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• 제24권3호
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• pp.167-173
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• 1997

The embryogenic callus (EC), from which somatic embryos could be induced, was compared with nonembryogenic callus(NE) to study the origin and features of totipotent cell in water dropwort (Oenanthe stolonifera DC). To induce and maintain of EC and the NE, meristematic stem and immature floret were inoculated in MS media supplemented with 1 mg/L 2,4-D, and with 2.5 mg/L NAA and 5mg/L BA, respectively, The EC was not induced from the NE even after subculturing in MS medium supplemented with 1 mg/L 2,4-D. Plantlets were not regenerated from the NE in hormone-free medium. In histochemical comparison of the EC with the NE by light microscopy, the EC had smaller cells in size, dense cytoplasm, and more starch granules of cells compared to the NE cells. The cell from the EC, as observed by transmission electron microscopy, had smaller vaculoes, well developed ribosomes, mitochondria, and endoplasmic reticulum, whereas the cells from the NE had larger vacuoles and underdeveloped organelles. In protein pattern from NE, EC and Somatic embryo (SE), as analyzed by SDS polyacrylamide gel electrophoresis, different proteins specific for tissue were observed: 17 and 28 KD for NE, 50, 52, 57, 66, 68 KD for EC and 20 KD for SE. DNA polymorphism was also observed between EC and NE as analyzed by RAPD (randomly amplified polymorphic DNA) method. The origin of totipotent stem cell and the relationship between irreversible genomic change arose in differentiation and the loss of totipotency in plant were discussed.

• 치위생과학회지
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• 제22권2호
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• pp.83-89
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• 2022

Background: Estrogen deficiency affects the structure and function of the salivary glands in women, leading to a decrease in salivary secretion and a change in the composition of saliva. Previous studies on changes in the salivary glands that cause estrogen deficiency have reported only partial results for the parotid and submandibular glands, and there are few comparative morphological studies of histological changes between the parotid and submandibular glands in ovariectomized rats (OVX) leading to estrogen deficiency. This study aimed to analyze the histopathological and histochemical changes in the parotid and submandibular salivary glands causing estrogen deficiency by using OVX, and to discuss the mechanism on these changes. Methods: The parotid and submandibular glands from sacrificed control and OVX groups were fixed with cold 4% paraformaldehyde in phosphate buffer (pH 7.2). The tissues were dehydrated using a series of graded ethyl alcohol and embedded in paraffin. For histopathological analysis, sections cut to a thickness of 6 to 7 ㎛ were stained with hematoxylin and eosin (H&E). For histochemical analysis, Periodic acid-Schiff (PAS), Alcian blue (AB, pH 2.5), and PAS+AB (pH 2.5 and pH 1) staining was performed. Results: Histopathological analysis of OVX tissue showed that the parotid and submandibular salivary glands were broadly and clearly separated and divided into lobes. In OVX, acinar and ductal cells with condensed polymorphic or pyknotic nucleus, which are presumed to be characteristic of apoptotic cells, and degenerated cells with lipid deposition in cytoplasmic granules and ruptured membranes were increased. Histochemical analysis of OVX, confirmed an increase in the number and acidification of acinar secretory granules. Conclusion: Histopathological and histochemical changes and the effects of estrogen deficiency are more evident in the submandibular salivary gland than in the parotid gland.

• 대한의생명과학회지
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• 제11권4호
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• pp.465-471
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• 2005

Ofloxacin has antimycobacterial activity that possibly contributes a pivotal role in the second-line drug regimens that are used for the treatment of multidrug-resistant tuberculosis. However, in some communities, the resistance rate of Mycobacterium tuberculosis to this agent is surging. Therefore, a rapid and accurate method that can be used to determine the resistance of M tuberculosis to the ofloxacin can be very useful for effective treatment of the patients. As an effort to develop such a method, this study was set up to reveal general types of mutations that are related to ofloxacin resistance of M tuberculosis. From previous studies, it has been well known that ofloxacin resistance is associated with mutations in a gene encoding the gyrase A subunit protein. In this study, we obtained 43 ofloxacin-resistant and 50 ofloxacin-susceptible M tuberculosis clinical isolates from Masan National TB Hospital, and sequences of DNA fragment of 320 bp, region of gyrA corresponding to the ofloxacin resistance-determining region were analyzed. In brief, the results showed that a total of seven mutation types were found at gyrA. Theses mutations were all clustered within nucleotides 2574 to 2586 of the gyrA gene (codons 88 to 94). Codon 94 was the most frequently substituted site. Twenty-four of the 43 isolates had mutations at this position resulting in a total of five different types of amino acid changes $(Asp{\to}Ala,\;Asp{\to}Gly,\;Asp{\to}His,\;Asp{\to}Tyr,\;and\;Asp{\to}Asn)$. Five isolates contained a mutation at codon 90 resulting $Ala{\to}Val$ change. Four isolates had mutations at codon 91 causing a $Ser{\to}Pro$ change at this site. Two isolates contained a mutation at codon 88 and each of them resulted in different types of amino acid changes $(Gly{\to}Cys,\;Gly{\to}Ala)$. On the other hand, polymorphic site at codon 95 was found in both ofloxacin-resistant and ofloxacin-susceptible isolates. From these results, we concluded that the rate of mutations present in gyrA among ofloxacin-resistant M. tuberculosis in Korea is similar to the general rates of mutations found throughout the world. Subsequently, an oligonucleotide probe was designed based on the results of sequence analysis and was used to develop a dot blot hybridization assay system to determine ofloxacin-resistance of M tuberculosis. To evaluate this probe, dot-blot hybridization was carried out using other 57 clinical isolates, and the results showed that the dot-blot hybridization assay is good for detecting sequence alterations atgyrA gene.

• 한국버섯학회지
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• 제14권2호
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• pp.64-69
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• 2016

큰느타리버섯 품종 육성을 위해 품질이 우수한 특성을 지니는 큰느타리버섯 KNR2598과 경도가 우수한 특성을 지니는 큰느타리버섯 KNR2610 모본으로부터 단핵균주를 분리 한 뒤 단포자간 교잡을 통해 고품질의 저온 저장성이 우수한 신품종 "단비5호"를 육성하였다. 신품종의 균사 생육 적정온도는 $25^{\circ}C$이며 자실체 발생 적정 온도는 $15{\sim}16^{\circ}C$ 이었다. 솎음 재배에서 발이소요일수를 포함한 수확소요일수는 대조품종인 큰느타리버섯 2호에 비해 0.5~1.7일 정도 빠른 특성을 보였다. 갓 색깔은 중간수준의 갈색이며 대 색깔은 흰색을 나타내었다. 갓모양은 우산형으로 850cc 플라스틱 병재배에서 한 개체의 평균무게는 $90.4{\pm}16.9g$이었다. "단비5호"와 대조품종간의 RAPD 분석결과 서로 다른 DNA 밴드양상을 보여 주었으며 대치배양을 통해 두품종간에 대치선을 확인 하였다. "단비5호"의 경우 $4^{\circ}C$에서의 저장성이 대조품종 대비 24.6~30.6일 이상 길게 유지되는 특성이 있어 수출적합형 품종으로 가치가 있을 것으로 기대된다.