• Korean journal of applied entomology
• /
• v.56 no.4
• /
• pp.377-385
• /
• 2017

Estimates of evolutionary sequence divergence and inference of a phylogenetic tree for eight delphacid planthopper species were based on the full-length nucleotide sequence of the internal transcribed spacer 2 (ITS2) region. Size of the ITS2 DNA sequence varied from 550 bp in Sogatella furcifera to 699 bp in Nilaparvata muiri. Nucleotide sequence distance ($d{\pm}S.E.$) was lowest between N. muiri and N. bakeri ($0.001{\pm}0.001$), and highest between Ecdelphax cervina and Stenocranus matsumurai ($0.579{\pm}0.021$). Sequence distance between N. lugens and other planthoppers ranged from $0.056{\pm}0.008$ (N. muiri) to $0.548{\pm}0.021$ (S. matsumurai). In the neighbor-joining phylogenetic tree, all planthoppers were clustered separately into a species group, except N. muiri and N. bakeri. The ITS2 nucleotide sequence of N. lugens was used to design four loop-mediated isothermal amplification (LAMP) primer sets (BPH-38, BPH-38-1, BPH-207, and BPH-92) for N. lugens species-specific detection. After the LAMP reaction of three rice planthoppers, N. lugens, S. furcifera, and Laodelphax striatellus, with the four LAMP primer sets for 60 min at $65^{\circ}C$, LAMP products were observed in the genomic DNA of N. lugens only. In the BPH-92 LAMP primer set, the fluorescence relative to that of the negative control differed according to the amount of DNA (0.1 ng, 10 ng, and 100 ng) and incubation duration (20 min, 30 min, 40 min, and 60 min). At $65^{\circ}C$ incubation, the difference was clearly observed after 40 min with 10 ng and100 ng, but with a 60-min incubation period, the minimum DNA needed was 0.1 ng. However, there was little difference in fluorescence among all DNA amounts tested with 20 or 30 min incubations.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.1 no.1
• /
• pp.9-17
• /
• 2000

Genetic variation in the domestic silkworm strains (Bombyx mori) and phylogenetic relationships between domestic silkworms and wild silkworms (B. mandarina) were investigated by using a portion of mitochondrial CGI gene sequences. Ten geographic strains of B. mori we sequenced were identical in the 410 bp-section of mitochondrial COI gene. This sequence was also identical to the homologous sequence of the four Gen-Bank-registered strains, but one strain of B. mori differed a single nucleotide (0.2%) from others. MtDNA homogeneity in the B. mori strains appears to be resulted from fixation into the mast frequent mtDNA type during the course of breeding for new strains, in which an extensive indoor rearing and removal of unwanted individuals were accompanied. In the comparisons between domestic and wild silkworms, some wild silkworms were closely related to domestic silkworms (0.2%-1.2% of divergence), but the others were not (2.7%-3.7% of sequence divergence). This result was also reflected in the phylogenetic analyses, showing two independent phylogenetic groups: one including all B. mandarina sequences and the other including both B. mandarina and B. mori sequences. Thus, domestic silkworms may have been derived from the ancestor of B. mandarina, which belongs to this group, alto-ough more extensive study will provide better understanding on this issue.

• Animal Systematics, Evolution and Diversity
• /
• v.11 no.4
• /
• pp.409-416
• /
• 1995

Forty samples of common rats (Rattus norvegicus caraco) from Cheongu, Korea, were used for the analyses of mitochondrial DNA (mtDNA) fragment patterns resulted from the digestion with eight restriction enzymes. A total of 36 fragments were recognized and six mtDNA clones were revealed . The nucleotide-sequence divergences (p) among six mtDNA clones ranged from 0.35% to 2.73%. moreover, the six clones were grouped into three major subgroups ; the first, second , and third subgroup were composed of 29 samples of three clones, ten samples of two clones, and one sample of one clone, respectively. The second and third subgroups were different in their mtDNa genotype of Pvu II from the first subgroup, and the third subgroup differed in the genotype of Dra I from other two subgroups. Futhermore, the maximum divergence among common rats from Korea in this study is greater than that among common rats from the United States and Japan by Brown and Simpson (1981). Further analyses with additional sample from other localities in Korea appeared to be necessary in order to clarify the taxnomic status of the distinct mtDNA subgroups.

• Journal of Plant Biotechnology
• /
• v.38 no.3
• /
• pp.234-240
• /
• 2011

The genus Paeonia belongs to the family Paeoniaceae having significant medicinal and ornamental importance. The present investigation was undertaken with an aim to understand phylogenetic relationships of three Paeonia species (P. lactiflora, P. obovata, and P. suffruticosa) that are widely distributed in China, Korea, and Japan, using nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) sequence and to compare the phylogeny results with investigations reported earlier using existed sequences of the same species. The size variation obtained among sequenced nrDNA ITS region was narrow and ranged from 722 to 726 bp. The highest interspecific genetic distance (GD) was found between P. lactiflora and P. suffruticosa or P. obovata. The phylogram obtained using our nrDNA ITS sequences showed non-congruence with previous hypothesis of the phylogeny between section Paeonia and section Moutan of genus Paeonia. This result was supported by the phylogenetic relations showed in the phylogram constructed with existed sequences in NCBI. The present study suggested that P. obovata belonging to section Paeonia was phylogenetically closer to P. suffruticosa representing section Moutan of genus Paeonia than P. lactiflora belonging to section Paeonia. The main reason of the paraphyly of section Paeonia is thought to be nucleotide additivity directly caused by origin hybridization. This study provides more sequence sources of genus Paeonia, and will help for further studies in intraspecies population, and their phylogentic analysis and molecular evolution.

• Korean Journal of Plant Taxonomy
• /
• v.53 no.3
• /
• pp.237-241
• /
• 2023

The genus Scrophularia L. (Scrophulariaceae) comprises 200-270 species worldwide and is a taxonomically challenging lineage, displaying morphological diversity and hybridization. S. kakudensis is morphologically similar to the closely related taxa S. kakudensis var. microphylla, S. pilosa, and S. cephalantha. Therefore, the purpose of this study was to sequence the chloroplast (cp) genome of S. kakudensis using next-generation sequencing and compare it to those of related taxa. The complete cp genome sequence of Scrophularia kakudensis was found to be 152,355 bp long, consisting of a pair of inverted repeats of 25,485 bp that separate a large single-copy (LSC) of 83,479 bp from small single-copy regions of 17,909 bp. The cp genome contained 78 protein-coding genes, 30 tRNAs, and four rRNAs. A phylogenetic analysis based on 78 protein-coding genes from six Scrophularia species showed S. kakudensis and S. cephalantha formed with 100% bootstrap values. We compared the complete cp genomes of S. kakudensis and S. cephalantha and identified seven sequence divergence regions: matK/rps16, rps16/trnQ, trnS/trnG, rpoB/trnC, trnS/trnG, rpl32/trnL, and ndhD/psaC. These regions may be useful for determining the phylogenetic relationships among S. kakudensis-related species.

• The Plant Pathology Journal
• /
• v.25 no.2
• /
• pp.142-150
• /
• 2009

The complete genome sequences of RNA3 and RNA4 of the 13 different Rice stripe virus (RSV) isolates were determined and characterized in this study to address the possible causes of the recent re-emergence of RSV that affected many rice fields in Korea. The genome size of each RNA segment varied among isolates and significant differences were observed in the intergenic region. There was up to 4% average divergence in the RNA4 nucleotide sequence among 13 Korean isolates and only 1.4% in the RNA3. Phylogenetic relationships among different Korean isolates revealed that there were at least 2 types of RNA3 and 4 distinct types of RNA4 genomes present in Korea. However, Korean isolates with one type of RNA3 predominate over the other while the occurrences of the RSV Korean isolates with the 4 types of RNA4 genome were not correlated to specific geographical areas. Results further indicate that RNA4 had diverged more than RNA3 and these differences in accumulation of mutations in the individual RNA segments indicate that genetic reassortment were likely to contribute to the genetic divergence in the 13 Korean isolates. All of the Korean-RNA3 sequences except for one isolate grouped with Chinese isolates (JY and Z). In contrast, the RNA 4 sequences segregated together with either Chinese (JY and Z) and Japanese (M and T) isolates but genetic relationships of Korean isolates- RNAs 3 and 4 segments to Chinese-Y isolate were low. Altogether, these results suggest that the occurrence of mixtures of RNAs 3 and 4 genotypes in the natural population of RSV may have contributed to the sudden outbreak in Korea.

• The Korean Journal of Zoology
• /
• v.36 no.1
• /
• pp.14-20
• /
• 1993

한국산 도룡농, Hvnobius leechii의 7개 집단에서 mitochondrial DNA(mtDNA)의 변이가 조사되었다. MtDNA의 크기에서의 차이는 관찰되지 않았으나 제한효소 인식 부위에서의 차이가 조사되었다. MtDNA의 절편 양상은 각 집단에서 동일하게 나타났다. 제한 효소로 처리하여 얻어진 절편의 비교에서 종내 변이는 염기 치환에 의하여 발생한 것임이 분석되어졌다. 특히 하동과 제주 집단은 몇개의 제한 효소 인식 위치에서 나머지 5개 집단과 뚜렷한 차이를 보였다. 염기치환율(p값)은 공통 절편 비율(p값)을 토대로 하여 얻어졌으며 그 값은 0.004에서 0.064의 범위 내의 값으로 측정되었다. 하동과 제주 집단을 제외한 5개 집단의 비교에서는 비교적 낮은 침의 염기 치환율을 보였으나 제주와 나머지 집단들과의 비교에서는 염기치환율이 높게 측정되었다. 염기 치환율과 관련지어 염기 분화 연대를 측정한 결과 도룡뇽 7개 집단은 3개의 group으로 나뉘어 졌으며 이들은 약 188만년전에 분화된 것으로 사료되어 진다.

• Molecules and Cells
• /
• v.26 no.3
• /
• pp.228-235
• /
• 2008

Thiol-dependent redox systems are involved in regulation of diverse biological processes, such as response to stress, signal transduction, and protein folding. The thiol-based redox control is provided by mechanistically similar, but structurally distinct families of enzymes known as thiol oxidoreductases. Many such enzymes have been characterized, but identities and functions of the entire sets of thiol oxidoreductases in organisms are not known. Extreme sequence and structural divergence makes identification of these proteins difficult. Thiol oxidoreductases contain a redox-active cysteine residue, or its functional analog selenocysteine, in their active sites. Here, we describe computational methods for in silico prediction of thiol oxidoreductases in nucleotide and protein sequence databases and identification of their redox-active cysteines. We discuss different functional categories of cysteine residues, describe methods for discrimination between catalytic and noncatalytic and between redox and non-redox cysteine residues and highlight unique properties of the redox-active cysteines based on evolutionary conservation, secondary and three-dimensional structures, and sporadic replacement of cysteines with catalytically superior selenocysteine residues.

• Parasites, Hosts and Diseases
• /
• v.47 no.4
• /
• pp.369-375
• /
• 2009

Diphyllobothrium nihonkaiense was first described by Yamane in 1986 but the taxonomical features have been obscure due to lack of critical morphologic criteria in its larval and adult stages. In Korea, this tapeworm had long been known as Diphyllobothrium latum. In this study, we observed 62 specimens collected from Korean residents and analyzed them by morphological features and nucleotide sequences of mitochondrial cox1 gene as well as the ITS1 region. Adult tapeworms were examined after carmine or trichrome stain. Longitudinal sections of the gravid proglottids showed an obtuse angle of about 150 degree between the cirrus sac and seminal vesicle. This angle is known as a major differential point compared with that of D. latum. Nucleotide sequence differences between D. latum and the specimens from Koreans represented 17.3% in mitochondrial DNA cox1 gene. Sequence divergence of ITS1 among 4 Korean isolates was 0.3% and similarity was 99.7% with D. nihonkaiense and D. klebanovskii. All of the Korean specimens analyzed in this study were identified as being D. nihonkaiense (n = 62). We propose its Korean name as "Dong-hae-gin-chon-chung" which means 'long tapeworm of the East Sea' for this newly analyzed diphyllobothriid tapeworm in Korea.

• Animal Systematics, Evolution and Diversity
• /
• v.9 no.2
• /
• pp.171-179
• /
• 1993

Thirty nine samples of striped field mice (Apodemus agrarius coreae Thomas) from eight localities in the Korean peninsula were used for the analyses of mitochondria1 DNA (mtDNA) fragment patterns resulted from the digestion with eight restriction enzymes. A total of 31 fragments were recognized and seven mtDNA clones were revealed: one clone consisted of 32 among 39 samples from eight localities (1 of 1 from Sogcho, 4 of 5 from Mt. Chiak, 3 of 3 from Mt. Weolak, 2 of 2 from Mt. Sogri, 2 of 2 from Mt. Deokyoo, 3 of 4 from Mt. Jiri, 2 of 4 from Haenam, and 15 of 18 from Cheongju). The nucleotide-sequence divergences (p) among seven mtDNA clones ranged from 0.2% to 2.3% and distinct subgroups were not resulted from the grouping of these clones. It is confirmed that striped field mcie from the Korean peninsula is a single subspecies of Apodemus agrarius (A. agrarius coreae) because they were not divided into separate subgroups in their mtDNA genotypes.