• Korean Journal of Plant Taxonomy
• /
• v.40 no.1
• /
• pp.1-15
• /
• 2010

Recognizing a basal group in a taxon is one of the most important factors involved in understanding the evolutionary history of that group of life. Many botanists have suggested a sister to all other angiosperms to understand the origin and rapid diversification of angiosperms based on morphological and fossil evidence. Recent technical advances in molecular biology and the accumulation of molecular phylogenetic data have provided evidence of the extant basal-most angiosperm which is a sister to all other angiosperms. Although it is still arguable, most plant taxonomists agree that Amborella trichopoda Baill., a species (monotypic genus and monotypic family) distributed in New Caledonia, is a sister to all other extant angiosperms based on evidence from the following molecular approaches: 1) classical phylogenetic analyses based on multiple genes (or DNA regions), 2) analyses of a tree network of duplicated gene families, and 3) gene-structural evidence. As an alternative hypothesis with relatively minor evidence, some researchers have also suggested that Amborella and Nymphaeaceae form a clade that is a sister to all other angiosperms. Debate regarding the basal-most angiosperms is still ongoing and is currently one of the hot issues in plant evolutionary biology. We expect that sequencing of the whole genome of Amborella as an evolutionary model plant and subsequent studies based on this genome sequence will provide information regarding the origin and rapid diversification of angiosperms, which is Darwin's so called abominable mystery.

• Korean Journal of Ichthyology
• /
• v.19 no.4
• /
• pp.274-285
• /
• 2007

The subfamily Chrominae of damselfishes (Teleostei: Pomacentridae) includes the genus Chromis and Dascyllus. They are found throughout the tropical oceans and form a major component of coral reef communities. There are 5 species of the Chrominae currently recognized in Korea. This study was conducted to infer phylogenetic position of two Korean Chromis species and one Dascyllus species within general category of their each genus in worldwide level. This study also includes one species of Japanese Dascyllus. In the phylogenetic analysis, the Japanese D. aruanus grouped with D. aruanus previously reported from French Polynesia. Korean Chromis fumea grouped with Australian C. nitida and the p-distance value between the two species is relatively very low (0.047). Korean C. notatus grouped together with C. flavomaculata (New Caledonia). In the sequence analysis of some Korean and Japanese damselfishes, there was no sequence variation between D. melanurus (Jeju, Korea) and D. melanurus (Indo-Pacific), but the sequences of the two populations were different in only one nucleotide sites from that of D. melanurus in Indonesian Archipelago. The sequences of Dascyllus aruanus (Japan) were different in two nucleotide sites from it in French Polynesia. There were high difference between the sequences of two Korean species, Chromis fumea and Korean C. notatus. The variations among mitochondrial cytochrome b sequences indicate that the gene sequence could be used as DNA barcode for identification of local populations of D. aruaus and D. melanurus as well as species level.

• The Korean Journal of Mycology
• /
• v.42 no.3
• /
• pp.239-242
• /
• 2014

In this study, endophytic fungi were isolated from leaves of four species of woody plants, Acer tagmentosum, Larix kaempferi, Abies holophylla, and Pinus koraiensis, on Mt. Hambaek, Gangwondo, Korea. The endophytic fungi were identified using morphological and sequences analysis of ITS regions. The fungal endophytes were identified as Talaromyces radicus, Myceliophthora verrucosa, Cryptosporiopsis diversispora, and Sphaerulina berberidis, which are the first record in Korea. The morphological and molecular phylogenetic characteristics of each strain were described.

• Journal of Plant Biotechnology
• /
• v.43 no.2
• /
• pp.164-173
• /
• 2016

To investigate the genetic basis of phenotypic differences, sequence variations were analyzed in 8 inbred watermelon lines by re-sequencing. The number of sequence variations differed depending on the chromosome. Only 12.9% of SNPs were found within genes, whereas the rest were detected in promoter or intergenic regions. SNP density analysis showed that there was a highly variable region at the end of chromosome 6, which is similar to previously published findings. However, this region with high SNP density did not show much variation between the lines. In contrast, highly conserved regions with a size of 6.5-10 Mb were found in chromosomes 10 and 11. Pathway analysis suggested that the DIMBOA (a natural antibiotic)-glucoside degradation pathway was significantly different between the lines, indicating that the eight lines may have different levels of pathogen resistance. Among the carbohydrate-related genes, the alpha-galactosidase gene was the most variable among the lines. Information from this study will be helpful in understanding the watermelon breeding process at the molecular level.

• Journal of Life Science
• /
• v.22 no.3
• /
• pp.293-297
• /
• 2012

The movement of vesicles from the neuronal cell body to specific destinations requires molecular motors. The squid giant axon represents a powerful model for studies of the axonal transport mechanism because the axoplasm can readily be separated from the sheath by simple extrusion. In a previous study, vesicular movements in the axoplasm of the squid giant axon were inhibited by the kinesin antibody. In the present study, we cloned and sequenced the cDNAs for squid brain KIFs. Amplification of the conserved nucleotide sequences of the motor domain by polymerase chain reaction (PCR) using first-strand cDNAs of the squid optic lobe identified six new KIF proteins. Motif analysis of the motor domains revealed that the squid KIFs are homologous to the consensus sequences of the mouse KIFs. The phylogenetic tree generated by using the maximum parsimony (MP) method, the neighbor-joining (NJ) method, the minimum evolution (ME) method, and the maximum likelihood (ML) method showed that squid KIFs are closest to mouse KIFs. These data prove the phylogenetic relationships between squid KIFs and mouse ones.

• The Korean Journal of Mycology
• /
• v.23 no.4 s.75
• /
• pp.310-317
• /
• 1995

The evolutionary relationships for 43 species in the taxa of the basidiomycetous yeast and related yeast-like fungi have been studied from the 43 18S rRNA partial sequences. Fibulobasidium inconspicuum showed a relatively close relationship to Filobasidiella neoformans. It is obvious that Tremella foliacea and Ustilogo rabenhorstiana form a independently different cluster from basidiomycetous yeast and seem to be phylogenetically distant from basidiomycetous yeast and each other. The basidiomycetous yeasts are believed more closely associated with Tremella foliacea than with Ustilago rabenhorstiana. The phenotypic criteria such as carotenoid pigments, teliospores, ballistospores seems not to be phylogenetically useful indicators.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.5 no.2
• /
• pp.157-168
• /
• 2000

Sea urchin S. intermedius occurring in the Korean east coast is a cold water species that belongs to the family Strongylocentrotidae of Echinoidea. Although it is known that there are nine species in the family, species identification criteria, phylogenetic relationships, time and process of evolution of the family members have not been uncovered clearly. In the present study, I tried to find some clues to such problems for S. intermedius by means of DNA sequences. For this, cytochrome c oxidase subunit I (COI), one of the mitochondrial genes that evolve fast and follow maternal inheritance was analyzed. DNA was extracted from the female gonad of S. intermedius, a segment of COI gene amplified by polymerase chain reaction (PCR), and finally a total of 1077 base pair sequence of COI obtained by cloning and sequencing the PCR product. The sequence was compared with homologous genes of other sea urchins and echinoderm species. Phylogenetic trees of the COI gene segment revealed that S. intenedius is a sister species of S. purpuratus which lives along the east coast of the Paciflc. With reference to the fossil records of sea urchins and genetic distances in the molecular phylogenies, it is estimated that the two species were separated about 0.89 million years ago when the earth temperature fluctuated significantly. The current disjunct distribution patterns of the two species and the climate change of the earth at the time of separation suggest that speciation might have occurred by vicariance. The COI gene sequence obtained here now can be used as a molecular character which discerns S. intermedius from the other sea urchin species of Strongylocentrotidae.

• Korean Journal of Plant Taxonomy
• /
• v.34 no.4
• /
• pp.335-358
• /
• 2004

To investigate molecular phylogenetic relationships and to test hypothesis of hybrid origin of Ranunculus cantoniensis (Ranunculaceae), the sequences of nrDNA and chloroplast DNA were analyzed for 8 taxa and 25 accessions including 5 accessions of outgroup. In the phylogenetic trees by analyses of maximum parsimony and maximum likelihood for ITS nrDNA sequences and combined data of psbA-trnH, rps16 and trnL sequences of cpDNA, R. cantoniensis was most closely related to R. chinensis, and then to R. taciroi and R. silerifolius. The molecular phylogenetic relationships were not congruent with the previous report that R. cantoniensis was most closely related to R. silerifolius. In the sequence analysis of ITS and psbA-trnH, rps16, trnL for R. cantoniensis and the related taxa, R. cantoniensis showed polymorphism. It supported that the polymorphism also was reported in chromosome number and karyotype of R. cantoniensis. Ranunculus cantoniensis shared the marker gene of R. chinensis and R. silerifolius in ITS, and one of R. silerifolius in cpDNA. These results supported the hypothesis that R. cantoniensis was caused by hybridization between R. chinensis and R. silerifolius based on chromosome number and karyotype, and also estimated that R. silerifolius might be of maternal origin and R. chinensis be paternal.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.56 no.4
• /
• pp.322-328
• /
• 2011

AFLP markers were employed to detect genetic diversity and genetic relationship among 26 accessions of foxtail millet collected from Korea. Analysis of 26 accessions of foxtail millet with nine AFLP primer set combinations detected a total of 170 bands, of which 145 (85.3%) showed polymorphic at the species level. The phenotypic diversity (Hs) calculated for the nine primer combinations ranged from 1.84 to 6.8, with an average of 3.85. The average phenotypic diversity values were 3.39 and 2.99 for accessions collected from Gangwon province (Group 1), and accessions collected from the other areas including Gyeonggi province (Group 2), respectively. In the cluster analysis of 26 accessions, two major groups were recognized at 73% genetic similarity. Group I includes 13 accessions, which were collected in Gangwon province, and 1 accession, which was collected in Gyeonggi province, with genetic similarity of 76.8%. Group II includes two accessions, which were collected in Gangwon province, and 10 accessions, which were collected in the other areas with genetic similarity of 78.9%. The presenting data on the assessment of genetic diversity and genetic relationships among Korean accessions of foxtail millet will be helpful for efficient collection or conservation strategy of foxtail millet germplasm in Korea.

• Korean Journal of Ecology and Environment
• /
• v.46 no.2
• /
• pp.301-309
• /
• 2013

Between May and August 2012, a massive cyanobacterial bloom with Anabaena has been occurred throughout the North Han River. Sampling was conducted at one station on each lake, L. Uham, L. Cheongpyung, and L. Paldang, where occurred a dense bloom, in 13 July. According to the microscopic examination, the blooms was dominated by one specific filamentous cyanobacterium Anabaena and other phytoplankton. Morphologically, previous literature proven that this Anabaena species is A. crassa (Lemmermann) Komark.-Legn. & Cronberg. However, identification of species in a mixed population is complicated due to limited morphological differences. Therefore, with live sample including trichome, akinete and heterocyst, the sequences of 16S rRNA gene of Anabaena isolates were cloned and analyzed, and three 16S rRNA gene sequences of 1188~1520 bp in length were obtained. It was shown from the homologous analysis results that the obtained 16S rRNA sequences were highly homologous to the relevant sequences of A. crassa in GenBank. The 16S rRNA sequences of 63 species were retrieved from GenBank, and the phylogenetic tree was constructed by using these sequences.