• Bulletin of the Korean Chemical Society
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• 제28권6호
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• pp.1063-1066
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• 2007

• International Journal of Industrial Entomology and Biomaterials
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• 제31권2호
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• pp.62-69
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• 2015

The Asian cavity-nesting honeybee, Apis cerana (Hymenoptera: Apidae), has been extensively studied for its biogeography and genetic diversity, but the molecules utilized in past studies were mainly ~90 bp long mitochondrial non-coding sequences, located between $tRNA^{Leu}$ and COII. Thus, additional molecular markers may enrich our understanding of the biogeography and genetic diversity of this valuable bee species. In this study, we reviewed the public genome database to find introns of cDNA sequences, with the assumption that these introns may have less evolutionary constraints. The six introns selected were subjected to preliminary tests. Thereafter, two introns, titled White gene and MRJP9 gene, were selected. Sequencing of 552 clones from 184 individual bees showed a total of 222 and 141 sequence types in the White gene and MRJP9 gene introns, respectively. The sequence divergence ranged from 0.6% to 7.9% and from 0.26% to 17.6% in the White gene and the MRJP9 introns, respectively, indicating higher sequence divergence in both introns. Analysis of population genetic diversity for 16 populations originating from Korea, China, Vietnam, and Thailand shows that nucleotide diversity (π) ranges from 0.003117 to 0.025837 and from 0.016541 to 0.052468 in the White gene and MRJP9 introns, respectively. The highest π was found in a Vietnamese population for both intron sequences, whereas the nine Korean populations showed moderate to low sequence divergence. Considering the variability and diversity, these intron sequences can be useful as non-mitochondrial DNA-based molecular markers for future studies of population genetics.

• International Journal of Industrial Entomology and Biomaterials
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• 제24권1호
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• pp.41-47
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• 2012

The Scarites aterrimus (Coleoptera: Carabidae) dwells exclusively on coastal sandy dunes. Previously, we investigated the nation-wide magnitude and nature of genetic diversity of the species using mitochondrial COI gene and found moderate to low magnitude of sequence diversity, the presence of closely related haplotypes, and relatively high gene flow estimate. Based on these observations we concluded that the species had no historical barriers that bolster genetic subdivision and possible population decline. In this study, we additionally sequenced mitochondrial COII gene from 23 individuals collected from 9 Korean localities to confirm previous findings. Sequencing of 688 bp COII gene provided 5 haplotypes ranging in sequence divergence from 0.145% to 0.291% (1 ~ 2 bp), further confirming low sequence divergence of the species. Gene flow estimates and genetic diversity estimates also support the previous findings that there had been no historical barriers that bolster genetic subdivision.

• Animal Systematics, Evolution and Diversity
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• 제27권1호
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• pp.1-17
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• 2011

Thais Roding, 1798, commonly known as rock-shell, is among the most frequently found gastropod genera worldwide on intertidal rocky shores including those of Japan, China, Taiwan and Korea. This group contains important species in many marine environmental studies but species-level taxonomy of the group is quite complicated due to the morphological variations in shell characters. This study examined the genetic variations and relationships among three Korean Thais species based on the partial nucleotide sequences of mitochondrial cox1 gene fragments. Phylogenetic trees from different analytic methods (maximum parsimony, neighbor-joining, and maximum likelihood) showed that T. bronni and T. luteostoma are closely related, indicating the most recent common ancestry. The low sequence divergence found between T. luteostoma and T. bronni, ranging from 1.53% to 3.19%, also corroborates this idea. Further molecular survey using different molecular marker is required to fully understand a detailed picture of the origin for their low level of interspecific sequence divergence. Sequence comparisons among conspecific individuals revealed extensive sequence variations within the three species with maximum values of 2.43% in T. clavigera and 1.37% in both T. bronni and T. luteostoma. In addition, there is an unexpectedly high level of mitochondrial genotypic diversity within each of the three Korean Thais species. The high genetic diversity revealed in Korean Thais species is likely to reflect genetic diversity introduced from potential source populations with diverse geographic origins, such as Taiwan, Hong Kong, and a variety of different coastal regions in South China and Japan. Additional sequence analysis with comprehensive taxon sampling from unstudied potential source populations will be also needed to address the origin and key factors for the high level of genetic diversity discovered within the three Korean Thais species studied.

• The Korean Journal of Ecology
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• 제19권3호
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• pp.223-230
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• 1996

Five measurements of species diversity (richness index, diversity index, evenness index, dominance index and species sequences-importance curve) and their relationships with sltitude, tree age and community type were studied in $T\v{o}gyusan$ National Park, Korea. Altitude and tree age were the major variables explaining the differences of species diversity in the whole forest. Species richness index, diversity index and evenness index of Quercus mongolica and Pinus densiflora communities were lower than those of Carpinus laxiflora, Q. serrata, Fraxinus mandshurica, Q. mongolica - P. densiflora communities than that in the other communities. The species sequence-importance curve of the forest communities in $T\v{o}gyusan$ coincided with the ideal curve calculated by the lognormal-distribution theory.

• Parasites, Hosts and Diseases
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• 제56권2호
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• pp.175-181
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• 2018

The giant roundworm Ascaris infects pigs and people worldwide and causes serious diseases. The taxonomic relationship between Ascaris suum and Ascaris lumbricoides is still unclear. The purpose of the present study was to investigate the genetic diversity and population genetic structure of 258 Ascaris specimens from humans and pigs from 6 sympatric regions in Ascaris-endemic regions of China using existing simple sequence repeat data. The microsatellite markers showed a high level of allelic richness and genetic diversity in the samples. Each of the populations demonstrated excess homozygosity (Ho0). According to a genetic differentiation index (Fst=0.0593), there was a high-level of gene flow in the Ascaris populations. A hierarchical analysis on molecular variance revealed remarkably high levels of variation within the populations. Moreover, a population structure analysis indicated that Ascaris populations fell into 3 main genetic clusters, interpreted as A. suum, A. lumbricoides, and a hybrid of the species. We speculated that humans can be infected with A. lumbricoides, A. suum, and the hybrid, but pigs were mainly infected with A. suum. This study provided new information on the genetic diversity and population structure of Ascaris from human and pigs in China, which can be used for designing Ascaris control strategies. It can also be beneficial to understand the introgression of host affiliation.

• 생명과학회지
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• 제19권9호
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• pp.1183-1189
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• 2009

조팝나무는 목본이며 약용으로 매우 중요하며 우리나라 산림청 지정 보호수종이다. 이 속내 7집단에서 85개체에 대해 ISSR (inter simple sequence repeats) 마커로 이들 집단에 대한 유전적 변이와 집단구조를 조사하였다. 65개의 다형성 좌위와 78개 ISSR 유전자형을 얻었다. 덕유산 집단과 능동산 집단에는 1개체 이상 공유하는 유전자형이 포함되어 있었다. 전체 유전적 다양도는 종수준과 집단수준에서 각각 0.293과 0.183이였다. 집단의 분화($G_{ST}$)는 0.373으로 나타났다. 따라서 전체 변이의 37.3%는 집단 간에 있었다. ISSR 마커로 한국 내 조팝나무 집단의 분화는 잘 분리되어 ISSR로 조팝나무 집단 연구에 유익하며 유전적 다양도와 집단구조의 통찰은 종보전에 대한 기초 정보로 활용할 수 있을 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.955-961
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• 2009

The aim of this study was to determine the specific polymorphic sites in cattle breeds and inter- and interbreed genetic variation among breeds and to develop a databank of Turkish native cattle mtDNA using sequence analysis. The entire D-loop region was analyzed based on DNA sequences in Turkish Grey, East Anatolian Red, South Anatolian Red, and Anatolian Black native breeds. In total, 68 nucleotide differences were observed at 26 different sites. The variable positions consisted of 22 transitions, two transversions, and two insertions, but no deletions. Haplotype number, haplotype diversity, nucleotide diversity, and mean number of pairwise difference values were found to be 17, 0.993, 0.00478, and 4.275, respectively. In addition, a phylogeny was developed by comparison among cattle populations for which the entire D-loop sequence was available. A high level of genetic variation was observed within and among the native cattle breeds.

• 한국통신학회논문지
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• 제27권6B호
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• pp.569-578
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• 2002

This paper proposes a new multicarrier code division multiple access (CDMA) system. The proposed multicarrier CDMA system provides the advantages that the transmission bandwidth is more efficiently utilized by using divided spreading sequence, time and frequency diversity is achieved in frequency selective nultipath (acting channel, and inter-carrier interference (ICI) can be minimized by using specific data and code pattern. In this system, transmitted data bits are serial-to-parallel converted to some parallel branches. On each branch each bit is direct-sequence spread-spectrum modulated by divided spreading sequences and transmitted using orthogonal carriers. The receiver providers a Rake for each carrier, and the outputs of Rakes are combined to get time and frequency diversity. This multicarrier CDMA system allows additional flexibility in the choice of system parameters. Upon varying system parameters, bit error rate (BER) performance is examined for the proposed multicarrier CDMA system. Simulation results show that the proposed multicarrier CDMA scheme can achieve better performance than the other types of conventional multicarrier CDMA systems.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.13-24
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• 2012

The genetic diversity of plant growth-promoting rhizobacterial (PGPR) fluorescent pseudomonads associated with the sugarcane (Saccharum officinarum L.) rhizosphere was analyzed. Selected isolates were screened for plant growthpromoting properties including production of indole acetic acid, phosphate solubilization, denitrification ability, and production of antifungal metabolites. Furthermore, 16S rDNA sequence analysis was performed to identify and differentiate these isolates. Based on 16S rDNA sequence similarity, the isolates were designated as Pseudomonas plecoglossicida, P. fluorescens, P. libaniensis, and P. aeruginosa. Differentiation of isolates belonging to the same group was achieved through different genomic DNA fingerprinting techniques, including randomly amplified polymorphic DNA (RAPD), amplified ribosomal DNA restriction analysis (ARDRA), repetitive extragenic palindromic (REP), enterobacterial repetitive intergenic consensus (ERIC), and bacterial repetitive BOX elements (BOX) analyses. The genetic diversity observed among the isolates and rep-PCR-generated fingerprinting patterns revealed that PGPR fluorescent pseudomonads are associated with the rhizosphere of sugarcane and that P. plecoglossicida is a dominant species. The knowledge obtained herein regarding the genetic and functional diversity of fluorescent pseudomonads associated with the sugarcane rhizosphere is useful for understanding their ecological role and potential utilization in sustainable agriculture.