• Parasites, Hosts and Diseases
• /
• 제60권6호
• /
• pp.393-400
• /
• 2022

Human infection with simian malaria Plasmodium knowlesi is a cause for concern in Southeast Asian countries, especially in Malaysia. A previous study on Peninsular Malaysia P. knowlesi rhoptry associated protein-1 (PkRAP1) gene has discovered the existence of dimorphism. In this study, genetic analysis of PkRAP1 in a larger number of P. knowlesi samples from Malaysian Borneo was conducted. The PkRAP1 of these P. knowlesi isolates was PCR-amplified and sequenced. The newly obtained PkRAP1 gene sequences (n=34) were combined with those from the previous study (n=26) and analysed for polymorphism and natural selection. Sequence analysis revealed a higher genetic diversity of PkRAP1 compared to the previous study. Exon II of the gene had higher diversity (π=0.0172) than exon I (π=0.0128). The diversity of the total coding region (π=0.0167) was much higher than those of RAP1 orthologues such as PfRAP-1 (π=0.0041) and PvRAP1 (π=0.00088). Z-test results indicated that the gene was under purifying selection. Phylogenetic tree and haplotype network showed distinct clustering of Peninsular Malaysia and Malaysian Borneo PkRAP1 haplotypes. This geographical-based clustering of PkRAP1 haplotypes provides further evidence of the dimorphism of the gene and possible existence of 2 distinct P. knowlesi lineages in Malaysia.

• Journal of Ginseng Research
• /
• 제35권4호
• /
• pp.399-412
• /
• 2011

Little is known about the genetics or genomics of Panax ginseng. In this study, we developed 70 expressed sequence tagderived polymorphic simple sequence repeat markers by trials of 140 primer pairs. All of the 70 markers showed reproducible polymorphism among four Panax species and 19 of them were polymorphic in six P. ginseng cultivars. These markers segregated 1:2:1 manner of Mendelian inheritance in an $F_2$ population of a cross between two P. ginseng cultivars, 'Yunpoong' and 'Chunpoong', indicating that these are reproducible and inheritable mappable markers. A phylogenetic analysis using the genotype data showed three distinctive groups: a P. ginseng-P. japonicus clade, P. notoginseng and P. quinquefolius, with similarity coefficients of 0.70. P. japonicus was intermingled with P. ginseng cultivars, indicating that both species have similar genetic backgrounds. P. ginseng cultivars were subdivided into three minor groups: an independent cultivar 'Chunpoong', a subgroup with three accessions including two cultivars, 'Gumpoong' and 'Yunpoong' and one landrace 'Hwangsook' and another subgroup with two accessions including one cultivar, 'Gopoong' and one landrace 'Jakyung'. Each primer pair produced 1 to 4 bands, indicating that the ginseng genome has a highly replicated paleopolyploid genome structure.

• 식물병연구
• /
• 제19권2호
• /
• pp.77-83
• /
• 2013

Bean yellow mosaic virus (BYMV; genus Potyvirus, family Potyviridae) causes severe losses to various legume species and a number of non-legume species, particularly freesia plants. In a survey of virus diseases in Gyeonggi province, Korea, BYMV isolates were identified from many cultivated freesia species. Here, we determined the complete nucleotide sequences of a BYMV freesia isolate (BYMV-Fr; accession number FJ492961). BYMV-Fr genome consists of 9,545 nucleotides (nt) excluding the poly (A) tail and encodes 3,057 amino acid (aa), with an AUG start and UAG stop codon, containing one open reading frame typical of a potyvirus polyprotein. The polyprotein of BYMV-Fr was divided to ten proteins and the cleavage sites of each protein were determined. The coat protein (CP) and polyprotein of BYMV-Fr were compared at the aa level with those of the previously reported 4 BYMV isolates. BYMV-Fr shared 90.1 to 97.1 and 91.0 to 92.5% at the CP and polyprotein homology. Interestingly, BYMV-Fr showed identities of a lower level at the nt level of 5' noncoding region (61.4 to 67.6%) and at the aa level of P1 (71.4 to 72.8%), comparing with four BYMV isolates. Based on the aa sequence diversity of CP and polyprotein, phylogenetic analysis with the four BYMV isolates showed two distinct groups and BYMV-Fr and most BYMV isolates were most closely related to the clover yellow vein virus among 52 potyviruses. To our knowledge, this is the first report of the complete genome sequence of BYMV freesia strain.

• 식물분류학회지
• /
• 제39권1호
• /
• pp.48-54
• /
• 2009

우리나라 특산식물이며 희귀식물인 만리화(물푸레나무과) 집단의 유전적 다양성을 조사하기 위하여 5 집단 84개체에 대한 ISSR (Inter-Simple Sequence Repeats) 표지자 분석을 실시하였다. 14개의 ISSR 프라이머에서 총 93개의 증폭산물을 관찰할 수 있었으며, 유전적 다양성을 나타내는 P (Percentage of polymorphic loci)값과 S.I. (Shannon's information Index)가 다른 관목류에 비해 비교적 낮게 나타났다. 집단별 유전적 다양성은 석병산집단 (P = 64.5%, S.I. = 0.281)과 설악산B집단(P = 62.4%, S.I. = 0.292)이 높았으며, 석개재집단(P = 37.6%, S.I. = 0.178)이 가장 낮았다. 전체 유전변이 중 30.6%가 집단간에 기인하는 것으로 나타났고, 나머지 69.4%는 집단내 개체간의 차이에서 기인하였다. 이러한 결과는 분포역이 매우 제한되어 있으며 불연속적으로 출연하는 희귀종이라는 점으로 미루어 볼 때 지역간의 유전자 교류가 원활하지 못해 나타난 결과라고 추정해 볼 수 있다. 유전적 거리를 이용하여 UPGMA 방법에 의한 유집분석을 실시한 결과, 집단의 지리적 격리정도와 유전적 연관성은 비교적 일치하는 경향이었다. 본 연구 결과, 만리화의 유전자원보존을 위해서는 자생지 보호와 더불어 동적인 현지외 보존(dynamic ex situ conservation)과 같은 보다 적극적인 대책이 요구되며, 더 높은 유전적 다양성을 확보하기 위해서는 소수의 집단에서 다수 개체를 선발하기보다는 집단당 소수 개체를 다수의 집단에서 선발하는 집단 위주의 보존이 더욱 효과적일 것으로 판단된다.

• Journal of Communications and Networks
• /
• 제5권4호
• /
• pp.374-385
• /
• 2003

The growing interest towards ultra-wideband (UWB) communications stems from its unique features such as baseband operation, ample multipath diversity, and the potential of enhanced user capacity. But since UWB has to overlay existing narrowband systems, multiple access has to be achieved in the presence of narrowband interference (NBI). However, existing baseband spreading codes for UWB multiple access are not flexible in handling NBI. In this paper, we introduce two novel spreading codes that not only enable baseband UWB multiple access, but also facilitate flexible NBI cancellation. We construct our codes using a single carrier or multiple carriers (SC or MC), which can be implemented with standard discrete-cosine transform (DCT) circuits. With our SC/MC codes, NBI can be avoided by simply nulling undesired digital carriers. Being digital, these SC/MC codes give rise to multiband UWB systems, without invoking analog carriers. In addition, our SC/MC codes enable full multipath diversity, and maximum coding gains. Equally attractive is their capability to reduce the number of interfering users, with simple matched filter operations. Comprehensive simulations are also carried out to corroborate our analysis.

• ETRI Journal
• /
• 제34권2호
• /
• pp.272-275
• /
• 2012

This letter studies the problem of exploiting multichannel diversity in a spectrum sharing system, where the secondary user (SU) sequentially explores channel state information on the licensed channels with time consumption. To maximize the expected achievable throughput for the SU, we formulate this problem as an optimal stopping problem, whose objective is to choose the right channel to stop exploration based on the observed signal-to-noise ratio sequence. Moreover, we propose a myopic but optimal rule, called one-stage look-ahead rule, to solve the stopping problem.

• 한국환경과학회지
• /
• 제28권10호
• /
• pp.899-905
• /
• 2019

Recently, an innovative method for wastewater treatment and nutrient removal was developed by combining the sequence batch reactor and membrane bioreactor to overcome pollution caused by shipboard sewage. This system is a modified form of the activated sludge process and involves repeated cycles of mixing and aeration. In the present study, the bacterial diversity and dominant microbial community in this wastewater treatment system were studied using the MACROGEN next generation sequencing technique. A high diversity of bacteria was observed in anaerobic and aerobic bioreactors, with approximately 486 species. Microbial diversity and the presence of beneficial species are crucial for an effective biological shipboard wastewater treatment system. The Arcobacter genus was dominant in the anaerobic tank, which mainly contained Arcobacter lanthieri (8.24%), followed by Acinetobacter jahnsonii (5.81%). However, the dominant bacterial species in the aerobic bioreactor were Terrimonas lutea (7.24%) and Rubrivivax gelatinosus (4.95%).

• Journal of Species Research
• /
• 제13권1호
• /
• pp.61-66
• /
• 2024

During an investigation of unrecorded prokaryotic species in Korea, six unrecorded bacterial strains were isolated from soil samples collected from Uljin-gun. Based on a similarity search using the 16S rRNA gene sequence of the isolated strains and the construction of the neighbor-joining phylogenetic tree, five strains were identified to the genus Pseudomonas of the family Pseudomonadaceae, while one strain was identified as a species belonging to the genus Paenibacillus of the family Paenibacillaceae. The details of these unreported species, including gram staining reaction, colony and cell morphology, basic biochemical characteristics, strain ID, and isolation source, are described in the description of the strains.

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 2001년도 한국생물과학협회 학술발표대회
• /
• pp.129.1-129
• /
• 2001

No Abstract, See Full Text

• 한국약용작물학회:학술대회논문집
• /
• 한국약용작물학회 2012년도 심포지엄 및 춘계학술발표회
• /
• pp.329-330
• /
• 2012