• 농촌계획
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• 제27권2호
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• pp.49-58
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• 2021

Rural and agricultural landscapes are important forms of land use in maintaining biodiversity. In addition humans are provided with various public functions from ecosystems and agricultural ecosystems. But the creation of a facility horticultural complex can be a space that can undermine the public interest function of the agricultural ecosystem. Therefore, this study aims to quantify the function of ecosystem services that land use changes affect biodiversity in Korea's rice paddy fields. The area subject to the study was selected as the largest agricultural complex in Korea due to rice paddy fields and land use changes, and field agriculture was also carried out simultaneously. The survey was conducted only in the fields of vegetation, insects, amphibians, and birds, four areas of biodiversity that are believed to have a high impact on changes in land use in agricultural landscapes. The valuation of ecosystem services in four areas of biodiversity derived from this study was evaluated as non-market value. As a result of quantitative evaluation, about 25 species of vegetation were reduced due to changes in land use. The diversity of about 40 species of aquatic insects that inhabit rice paddies among insects has disappeared due to the creation of a horticultural complex. Birds and amphibian reptiles were also found to have decreased diversity and populations. This research is expected to be used in various ways to develop policies to enhance ecosystem service functions.

• Molecules and Cells
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• 제45권11호
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• pp.846-854
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• 2022

Neurons make long-distance connections via their axons, and the accuracy and stability of these connections are crucial for brain function. Research using various animal models showed that the molecular and cellular mechanisms underlying the assembly and maintenance of neuronal circuitry are highly conserved in vertebrates. Therefore, to gain a deeper understanding of brain development and maintenance, an efficient vertebrate model is required, where the axons of a defined neuronal cell type can be genetically manipulated and selectively visualized in vivo. Placental mammals pose an experimental challenge, as time-consuming breeding of genetically modified animals is required due to their in utero development. Xenopus laevis, the most commonly used amphibian model, offers comparative advantages, since their embryos ex utero during which embryological manipulations can be performed. However, the tetraploidy of the X. laevis genome makes them not ideal for genetic studies. Here, we use Xenopus tropicalis, a diploid amphibian species, to visualize axonal pathfinding and degeneration of a single central nervous system neuronal cell type, the retinal ganglion cell (RGC). First, we show that RGC axons follow the developmental trajectory previously described in X. laevis with a slightly different timeline. Second, we demonstrate that co-electroporation of DNA and/or oligonucleotides enables the visualization of gene function-altered RGC axons in an intact brain. Finally, using this method, we show that the axon-autonomous, Sarm1-dependent axon destruction program operates in X. tropicalis. Taken together, the present study demonstrates that the visual system of X. tropicalis is a highly efficient model to identify new molecular mechanisms underlying axon guidance and survival.

• 한국동물학회지
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• 제7권1호
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• pp.33-38
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• 1964

한국산 도롱뇽 (Hynobius leechi BOULENGER) 발생배의 질소화합물의 대사를 연구하고져 발생단계에 따른 단백질구성(아미노) 산의 촉진(아미노) 산의 정성적 분석과 질소 배설물(ammonia, urea, uric acid, creatine and/or creatinine, total nitrogen)의 정량분석을 미수정란, 란할배, 포배, 양배, 신경배 및 부화직전의 배에 대하여 행하였다. 1. 발생단계에 따른 발생배내 단백질구성 (아미노산)은 전 단계를 통하여 일양하게 18종씩 검출되어TRh 유리 (아미노산) 은 17 내지 23 종 검출되었으며, 전체적으로 유리(아미노산) 분포상에 큰 변화가 없었다. 2. 발생단계에 따른 질소배설물 분석의 결과는 다음과같다. Ammonia 와 urea 의 배내 함량은 미수정란에서부터 양배까지 점차 감소하여 양배 이후 부화직전배까지 급격히 증가한다. Uric acid의 함량은 전 단계를 통해 미소하였으며 creating and/or creatininie 은 본 실험에서는 검출되지 않았다. 3. 발생단계에 따른 발생배내 ammonia 함량에 대한 sodium azide의 영향은 농도에 따라 이원적인 특이성을 가지고 있었다.

• 한국동물학회지
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• 제22권1호
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• pp.26-38
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• 1979

In recent years some very substantial advances have been made in our understanding of oogenesis as a result of studies on a relatively few, very diverse species of animals. In this lecture I will (1) outline normal oogenesis using an advanced insect, Drosophila melanogaster, as an example, (2) show how oogenesis can be dissected genetically by studying the ovarian pathologies of flies homozygous for various recessive, female sterile genes, and (3) discuss how estimates can be made of the fraction of the Drosophila genome devoted to oogenesis. Then I will describe studies on mutations that block vitello-genesis in Drosophila and indicate what they tell us about inter actions between the ovary, the fat body and the endocrine system. I will next discuss the evolutionary mechanisms that have been adopted in higher insects and amphibians to produce the prodigious quantities of ribosomes stored in oocytes. I will end with an account of the results of recent stuides on amphibian lampbrush chromosomes which show how messenger RNAs are transcribed during oogenesis.

• Journal of Species Research
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• 제1권1호
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• pp.87-99
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• 2012

Before the construction of Hantangang dam, we surveyed vertebrate fauna along the Hantangang River and collected samples. We collected 248 specimens (1,394 individuals) of 41 fish species from 10 families in four orders, including 17 endemic species and 5 endangered species. In our herpetofauna survey, we collected 47 amphibian samples of 10 species from 5 families in 2 orders, and 19 reptile samples of 5 species from 2 families in 1 order. We observed 25 species of bird (6 orders, 14 families) inclulding collection of 51 bird specimens (10 species from 5 families in 1 order). We collected 91 mammals of 6 species, and identified 7 species from field sign and direct observation from a total of 10 families in 5 orders. This collection and list comprise the final vertebrate faunal survey of the Hantangang region, and will provide basic scientific information for future research on conservation and restoration of the region.

• Ecology and Resilient Infrastructure
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• 제5권1호
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• pp.54-58
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• 2018

Diet composition of amphibians usually reflects the distribution of potential prey within habitats, as well as their diet preference. We identified the diet items of Japanese tree frog (Hyla japonica) using a stomach flushing method in a rice paddy for the establishment of bio-monitoring systems of landscape changes. During the reproductive period, 71% of calling males had empty stomachs. All prey items in the stomachs belonged to the phylum Arthropoda, from eight orders of Insecta and one order of Arachnida. Among insect prey, the most common items in the stomachs were adults of beetles, flies and bugs, and larvae of butterflies and moths. There was a significant positive correlation between the body mass of Japanese tree frogs and the volume of prey items. Our results can provide a basic framework to guide the monitoring systems using prey identification of Japanese tree frogs.

• 한국동물학회지
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• 제8권2호
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• pp.47-50
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• 1965

양서류 오종 Bombina orientalis , Cacopoides borealis , Bufo bufo asiaticus, Rana nigromaculata nigromaculata, Rana rugosa 의 혈청단백질을 Paper electrophoresis 의 방법으로 분석비교하였다. 그 결과 Bombina orientalis 의 혈청단백질은 인간의 것과 마찬가지로 5개의 protein fraction으로 나누어지고 그중 fraction III 단백지링 가장 많은 함량을 구성하며 peak 가 가장 높다. Cacopoides borealis 와 Bufo bufo asiaticus 의 혈청단백질은 4개의 protein fraction 으로 나누어지는데 Cacopoides boreealis 에서는 fraction IV protein이 Bufo bufo asiaticus 에서는 fraction I protein 이 가장 많은 함량을 구성하고 있다. Rana nigromaculata nigromacuata 와 Rana rugosa 는 graph 상에 나타난 peak로 보면 상호유사하나 protein fraction 수는 차이가 있다. 그리고 albumin은 전 함량 per centage의 약 반을 차지하고 있다. 즉 종간의 거리가 멀수록 protein fraction 의 차이가 percentage 함량에 있어서 명백하여짐을 암시하여준다.

• Animal cells and systems
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• 제8권2호
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• pp.81-87
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• 2004

Male red-spotted newts, Notophthalmus viridescens, use chemical cues to locate and select potential mates. To investigate whether large and small males respond differentially to chemical cues from conspecifics, we conducted a series of two-choice Y-maze tests with odorant stimuli from two large females (LF/LF), one large versus one small female (LF/SF), and one large female placed with four males versus one small female (LF+4M/SF). We found that males responded more rapidly in a LF/LF choice situation than in those involving LF/SF or LF+4M/SF. In addition, small males chose more quickly than did large males. These results suggest that both body size and odorant context affect the speed of odorant responses. By responding differentially to conspecific chemical cues, small males may arrive earlier at a courting area, increasing their chances of successfully guarding and mating with a female.

• 한국동물학회지
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• 제36권1호
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• pp.84-96
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• 1993

한국산 도롱뇽(Hynobius leechii) 유생의 다리 발생 과정을 관찰하고 잠재적 돌연변이 유발물질인 제-methyl-N'-nitro-N-nitrosoguanidine(MNNG)과 잠재적 기형 유발물질인 retinol palmitate가 다리 발생에 미치는 영향을 알아보았다. 정상적인 개체에서 됫다리의 발생 단계는 외부와 내부의 형태적 특징을 기준으로 하여 7단계로 나누어 볼 수 있었으며 전연골세포의 밀집에 따른 골격형성은 다리 발생아의 근위부에서 시작하여 원위부로 진행됨을 확인할 수 있었다. 도롱뇽 유생을 MNNG(10 rpm)나 retinol palmitate(37.5 lpm)로 처리한 경우, 공통적으로 다리 원위부의 골격 형성이 억제되었으며, 특히 이러한 골격 형성 억제 현상은 처리시기가 이를수록 보다 심하게 나타났다. 이러한 결과는 발생을 저해하는 물질에 대한 미분화 상태의 세포들의 반응성이 발생과정 중 특정 단계에 국한됨을 시사하는 것으로 해석된다.

• Animal cells and systems
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• 제6권4호
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• pp.301-304
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• 2002

In our previous study, we have shown that Fgf-8 is expressed in the basal layer of the apical epithelial cap (AEC) and in the underlying thin layer of mesenchymal tissue of the regenerating limbs of Mexican axolotl, Amby-stoma mexicanum. Our present RT-PCR data also demonstrate that Fgf-8 transcript is localized both in the mesenchymal and epidermal tissues. To understand the effect of retinoic acid (RA) on the expression of Fgf-8 in the regenerating axolotl limbs, RA was injected intraperitoneally at the dediffer-entiation stage of limb regeneration. The RA treatment caused 8 change in the Fgf-8 expression profile of the regenerating limbs. In RA-treated limbs, duration of Fgf-8 expression was prolonged and a high level of expression was maintained during dedifferentiation and blastema formation stages. These results suggest that Fgf-8 is an important molecule in the process of pattern duplication of regenerating salamander limbs evoked by RA treatment.