• 한국응용곤충학회지
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• 제47권3호
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• pp.201-208
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• 2008

성페로몬 트랩을 이용하여 사과재배지를 중심으로 복숭아순나방(Grapholita molesta) 월동집단의 발생패턴을 조사하였다. 복숭아순나방의 발생은 남부지역에서 더 일찍 시작되었지만, 발생밀도는 비슷한 지역이라도 사과원에 따라 상이하게 나타났다. 월동집단의 성충은 사과원 내부에서 모니터링한 자료와 이웃하는 사과원 사이 지점에서 포획된 밀도 변화가 서로 유사하여 이들의 사과원 사이 이동이 가능한 것으로 추정되었다. 그러나 사과원 내부에서 서로 다른 지점에서 모니터링한 자료는 바람이 불어오는 가장자리 지점이나 이웃하는 사과원과 가까이 위치한 트랩에서 높은 포획 밀도를 보여, 이들의 이동이 사과원 안에서는 둔화될 수 있다고 추정된다. 월동세대가 나타나는 비교적 초기(4월 20-25일)에 서로 다른 사과원에 발생하는 월동세대의 유전적 거리를 분석하였다. PCR-RAPD법으로 분석한 결과, 이들 집단들 사이에 유전적 분화가 있음을 나타냈다. 더욱이 동일한 지역에서 전년도 가을 집단과 초봄의 월동집단 사이에 유전적 차이가 뚜렷하게 나타나서, 이러한 월동세대 집단간 차이는 겨울 기간동안의 지역간 상이하게 나타날 수 있는 도태압에 따른 유전적 병목현상에 기인된 것으로 제시된다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권2호
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• pp.212-218
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• 2020

Objective: Agu pigs are indigenous to the Okinawa prefecture, which is the southernmost region of Japan. Agu pigs were exposed to a genetic bottleneck during the 20th century, due to the introduction of European pig breeds. The objective of this study was to elucidate the genetic structure of Agu pigs and to determine their relationships with those of five European breeds, two Chinese breeds and Ryukyu wild boar using microsatellite markers. Methods: A total of 203 DNA samples from 8 pig breeds were used in this study. Genotyping was performed using 21 microsatellite markers distributed across 17 chromosomes. Results: Numbers of effective alleles in Agu pigs were fewer than in European breeds and Ryukyu wild boar. Among domestic pigs, Agu pigs had the lowest heterozygosity (0.423) and highest inbreeding coefficient (F_IS = 0.202), indicating a severe loss of heterozygosity in Agu pigs possibly due to inbreeding. Neighbor-joining tree analysis was performed based on Reynolds' genetic distances, which clustered Agu pigs with Duroc pigs. However, principal component analysis revealed a unique genetic position of the Agu pig, and the second principal component separated Agu pigs from all other breeds. Structure analysis with the optimal assumption of seven groups (K = 7) indicated that Agu pigs form an independent cluster from the other breeds. In addition, high and significant F_ST values (0.235 to 0.413) were identified between Agu pigs and the other breeds. Conclusion: This study revealed a substantial loss of genetic diversity among Agu pigs due to inbreeding. Our data also suggest that Agu pigs have a distinctive genetic structure, although gene flows from European breeds were observed.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.880-886
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• 2015

Bacterial heme was produced from a genetic-engineered Escherichia coli via the porphyrin pathway and it was useful as an iron resource for animal feed. The amount of the E. coli-synthesized heme, however, was only few milligrams in a culture broth and it was not enough for industrial applications. To analyze heme biosynthetic pathways, an engineered E. coli artificially overexpressing ALA synthase (hemA from Rhodobacter sphaeroides) and pantothenate kinase (coaA gene from self geneome) was constructed as a bacterial heme-producing strain, and both the transcription levels of pathway genes and the intermediates concentrations were determined from batch and continuous cultures. Transcription levels of the pathway genes were not significantly changed among the tested conditions. Intracellular intermediate concentrations indicated that aminolevulinic acid (ALA) and coenzyme A (CoA) were enhanced by the hemA-coaA co-expression. Intracellular coproporphyrinogen I and protoporphyrin IX accumulation suggested that the bottleneck steps in the heme biosynthetic pathway could be the spontaneous conversion of HMB to coproporphyrinogen I and the limited conversion of protoporphyrin IX to heme, respectively. A strategy to increase the conversion of ALA to heme is discussed based on the results.

• Animal Systematics, Evolution and Diversity
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• 제28권4호
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• pp.279-290
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• 2012

Plecoglossus altivelis (ayu) is an amphidromous fish widely distributed in Northeastern Asia from the East China Sea to the northern Japanese coastal waters, encompassing the Korean Peninsula within its range. The shore lines of northeastern region in Asia have severely fluctuated following glaciations in the Quaternary. In the present study, we investigate the population genetic structure and historical demographic change of P. altivelis at a population level in East Asia. Analysis of molecular variance (AMOVA) based on 244 mitochondrial control region DNA sequences clearly showed that as the sampling scope extended to a larger geographic area, genetic differentiation began to become significant, particularly among Northeastern populations. A series of hierarchical AMOVA could detect the genetic relationship of three closely located islands between Korea and Japan that might have been tightly connected by the regional Tsushima current. Neutrality and mismatch distribution analyses revealed a strong signature of a recent population expansion of P. altivelis in East Asia, estimated at 126 to 391 thousand years ago during the late Pleistocene. Therefore it suggests that the present population of P. altivelis traces back to its approximate demographic change long before the last glacial maximum. This contrasts our a priori expectation that the most recent glacial event might have the most crucial effect on the present day demography of marine organisms through bottleneck and subsequent increase of effective population size in this region.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권4호
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• pp.191-198
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• 2022

Natural habitats of the Korean long-tailed goral (Naemorhedus caudatus) have been fragmented by anthropogenic activities in South Korea in the last decades. Here, the individual identity, genetic variation, and population differentiation of the endangered species were examined via the multiple-tube approach using a non-invasive genotyping method. The average number of alleles was 3.16 alleles/locus for the total population. The Yanggu population (1.66) showed relatively lower average number of alleles than the Inje population (3.67). Of the total 19 alleles, only seven (36.8%) alleles were shared by the two populations. Using five polymorphic out of six loci, four and six different goral individuals from the captive Yanggu (n=24) and the wild Inje (n=28) population were identified, respectively. The allele distribution was not identical between the two populations (Fisher's exact test: P<0.01). A considerably low migration rate was detected between the two populations (no. of migrants after correction for size=0.294). Additionally, the F statistics results indicated significant population differentiation between them, however, quite low (F_ST=0.327, P<0.01). The posterior probabilities indicated that the two populations originated from a single panmictic population (P=0.959) and the assignment test results designated all individuals to both populations with nearly equal likelihood. These could be resulted from moderate population differentiation between the populations. No significant evidence supported recent population bottleneck in the total Korean goral population. This study could provide us with useful population genetic information for conservation and management of the endangered species.

• Asian-Australasian Journal of Animal Sciences
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• 제24권8호
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• pp.1048-1052
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• 2011

The Chinese Holstein cattle breed, an introduced breed in China, has been crossbred with native cattle breeds. We hypothesised that the Chinese Holstein local population in Beijing share haplotypes with native Asian cattle breeds, the result of a sudden population expansion in the recent past. We also hypothesised that crossbreeding and population expansion left traces that shaped the genetic makeup of the breed. Evaluation of this was performed by mitochondrial DNA (mtDNA) sequence analysis of Chinese Holstein cattle from Beijing (n = 41) and a comparison of them with the published mtDNA sequences (n = 293) of 14 Asian breeds with an emphasis on Chinese native cattle breeds. Three shared common haplotypes between Chinese Holstein cattle and native Asian cattle were found. Moreover, a high level of haplotype diversity in Chinese Holstein cattle (h = 0.9557) and low nucleotide diversity (${\pi}$ = 0.0052) was found, indicating a past population bottleneck followed by rapid population growth. These findings are supported by the significantly negative deviation of Tajima's D (-1.82085), the star-like pattern of dominant haplotypes and the pairwise mismatch distribution analysis, which showed a unimodal pattern.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권2호
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• pp.108-113
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• 2021

Detrimental effects of inbreeding have been studied by many researchers for a long time. However, only a few studies have shown the occurrence of inbreeding depression due to evolutionary changes as a purging process. In this study, two different populations (inbreeding and outbreeding) of Drosophila melanogaster were compared to assess inbreeding effects on artificial population bottlenecks. For inbreeding conditions, a couple of D. melanogaster (one virgin and one male) were selected from an inbred population and cultured in a vial. For outbreeding conditions, a couple of D. melanogaster were selected from different populations and cultured in a vial. There were significant differences in body lengths of adults, but not in other parameters such as the total number of adults, the rate of survival, and the rate of wing mutants. The mean body length of adults of outbreeding populations was longer than that of inbreeding populations in the first generation (G1; P = 0.004), but not in the second generation (G2; P = 0.066). Although the other three parameters (total number of adults, rate of survival, and rate of wing mutants) showed differences in their mean values between inbreeding and outbreeding populations, these differences were not statistically significant. This might be due to genetic purging. This study demonstrated one additional experimental case related to inbreeding depression in artificial bottlenecked populations. Further studies are necessary to confirm the clear interaction between inbreeding depression and genetic purging using more generations and replicates (or samples) of D. melanogaster.

• 산업경영시스템학회지
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• 제36권4호
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• pp.116-122
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• 2013

This study develops a dynamic scheduling model for parallel machine scheduling problem based on genetic algorithm (GA). GA combined with discrete event simulation to minimize the makespan and verifies the effectiveness of the developed model. This research consists of two stages. In the first stage, work sequence will be generated using GA, and the second stage developed work schedule applied to a real work area to verify that it could be executed in real work environment and remove the overlapping work, which causes bottleneck and long lead time. If not, go back to the first stage and develop another schedule until satisfied. Small size problem was experimented and suggested a reasonable schedule within limited resources. As a result of this research, work efficiency is increased, cycle time is decreased, and due date is satisfied within existed resources.

• 식물분류학회지
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• 제37권2호
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• pp.115-129
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• 2007

제주도에 자생하는 희귀식물종인 황근(아욱과) 3개 집단을 대상으로 ITS 염기서열 변이와 ISSR 변이를 분석하는 방법으로 유전적 다양성을 조사하였다. 집단 1(북제주군 하도리 집단)에 포함된 18개체의 ITS 염기서열을 분석한 결과 총 14개 지점(다형 뉴클레오티드까지 포함하면 17개 지점)에서 뉴클레오티드 변이가 관측되었으며, 각 개체들은 최소 1개에서 최대 13개 뉴클레오티드 지점에서 염기서열의 차이를 보였다. 그러나 집단 2(남제주군 오조리 집단) 17개체와 집단 3(남제주군 세화리 집단) 17개체의 ITS 염기서열은 모두 동일한 것으로 확인되었다. ISSR 변이분석 방법에 의해 생산된 자료를 분석한 결과 역시, 집단 1이 집단 2와 3에 비해 상대적으로 더 높은 유전적 다양성 지표들을 나타내었다. 이와 같은 결과는 집단 2와 3의 형성 과정에서 극심한 유전적부동이 존재했었으며, 이후 인접 집단으로부터 이들 집단으로의 유전자 유입이 매우 제한적이었던 반면, 집단 1은 오랫동안 개체군이 안정적으로 유지되어왔기 때문으로 해석되었다. 우리나라에 자생하는 황근을 보존하기 위해서는 유전적 다양성이 월등히 더 높은 하도리 집단을 우선적으로 보존하는 것이 매우 중요하며, 만일 현지외 보존이 필요할 경우 하도리 집단에 포함된 개체를 집중적으로 활용하는 것이 더 효율적일 것으로 판단된다.

• 한국어류학회지
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• 제31권4호
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• pp.187-194
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• 2019

학꽁치(Hyporhamphus sajori)의 유전적 다양성과 집단구조를 조사하기 위해 동북아시아에서 시료를 채집하여 mitochondrial DNA control region (mtDNA CR)을 분석하였다. 시료는 중국(Liaoning), 한국(통영), 일본(Wakasa Bay) 3곳에서 총 70개체를 채집했고, 일본 3곳(Wakasa Bay, Toyama Bay and Mikawa Bay)에서 분석된 47개체의 mtDNA CR 염기서열을 Genbank에서 다운로드했다. 분석결과 총 358 bp가 나타났고, 7개의 변이와 함께 haplotype이 7개 확인되었다. Haplotype diversity과 nucleotide diversity는 각각 0~0.295±0.156 및 0~0.0009±0.0011이고, main haplotype을 94%의 개체가 공유했다. 매우 낮은 haplotype diversity와 nucleotide diversity 그리고 starlike minimum spanning tree는 집단이 최근에 병목현상을 거친 후, 팽창되었음을 나타낸다. 집단 간에 Pairwise F_ST 값은 낮고 유의하지 않은 것으로 나타났고, 이것은 집단 간 gene flow가 있음을 시사한다. 학꽁치의 genetic homogenity는 부유조와 해류가 주요 원인으로 생각된다.