• Korean Journal of Plant Taxonomy
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• v.42 no.4
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• pp.267-274
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• 2012

To understand morphological and genetic differentiation between Euphorbia esula and E. maackii we examined 12 morphological characters and 11 isozyme loci from 14 populations of two species. Species of E. esula complex (A = 1.63, P = 44.83, $H_e$ = 0.198) in Korea maintain nearly as high as the genetic diversity reported in East Asian E. jolkinii and E. fauriei while lower than those of E. ebracteolata and E. pekinensis in Korea. Although the ranges of most morphological character variation of the two species overlap, E. esula and E. maackii were well recognized by the combination of the morphological traits, and the result of UPGMA phenogram supports the two distinct species inhibited in Korea. However, isozyme data do not support the recognition of E. esula and E. maackii. The discordance between morphological and allozyme data should be explained by the recent divergence or gene flow via introgressive hybridization between two species.

• Journal of Life Science
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• v.14 no.4
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• pp.593-607
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• 2004

The nucleotide sequence for a nuclear-encoded small subunit rDNA (SSU rDNA) was determined for 43 species of the class Dinophyceae, including harmful algae Cochlodinium polykrikoides and Gyrodinium aureolum. These sequences and data analyses were performed by parsimony, distances and maximum likelihood methods in PHYLIP (Phylogenetic Inference Package) version 3.573c. The species Noctiluca scintillans, Gonyaulax spinifern and Crypthecodinium cohnii occupied a basal position within the Dino- phyceae in our analyses. The genera Alexandrium and Symbiodinium were monophyletic (supported by a bootstrap value of >70%), whereas the genera Gymnedinium and Gyrodinium formed polyphyletic nodes, for which bootstrap support was strong (>70%) in the neighbor-joining and maximum likelihood methods except for the PHYLIP parsimony analysis (=59%). The sequence divergence between G. aureolum and G. dorsum/ G. galathenum was the largest at 7.4% (45 bp), whereas G. aureolum and G. mikimotoi showed an extremely low value of genetic divergence of 0.9% (5 bp). The genetic divergence between C. polykrikoides and G. aureolum was a low value of 5.2% (31 bp). In the phylogenetic analysis, the placement of G. aureolum and C. polykrikoides was closer to the genus Gymnodinium than to the genus Gyrodinium, which was supported by a moderate bootstrap value.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.63-68
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• 2003

We investigated the sequence divergence of the geographic samples of the queen bumble bee (Bombus ardens) in Korea. A portion of mitochondrial COI gene sequences (423 bp) was analyzed for 44 individuals collected from seven localities. Sequence analysis resulted in four COI haplotypes with the maximum nucleotide divergence of only 0.5% (two bp). One haplotype (BA1) was dominant in all localities surveyed (86.4%). The finding of low sequence divergence and dominance of one haplotype appear to reflect, although limited, the life history of the B. ardens queens subjected to active dispersal and seasonal fluctuation in queen number.

• Animal Systematics, Evolution and Diversity
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• v.37 no.3
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• pp.225-228
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• 2021

Eleven Gonioctena species have been recorded in the Korean Peninsula. Most species in the genus have very similar coloration and morphology. The male genitalia is generally used as the only reliable diagnostic character differentiating closely related species, but it is still difficult to identify females to species accurately. Here, we determined the COI barcodes of two Gonioctena species described from Korea and give morphological descriptions. The interspecific genetic divergence (Kimura 2-parameter) among the Gonioctena ranged from 0.073 to 0.138 and averaged 0.108. The pairwise genetic distance between the two Korean species(0.102) is similar to the average interspecific divergence. We predict that these analyses will help to resolve taxonomic issues and find cryptic species.

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.65.1-65
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• 1996

No Abstract, See Full Text

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.2
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• pp.107-112
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• 2007

The mole crickets, Gryllotalpa, are insect pest distributed in the world. In Korea, G. orientalis was reported to occur, but previous ecological studies suggested the presence of two ecological types. To test this hypothesis, we sequenced a portion of mitochondrial (mt) genome from 48 G. orientali individuals collected over five Korean localities: Busan, Suwon, Okchon, Wonju, and Gangneung. From the sequence analysis, only two haplotypes were obtained, but the sequence divergence between the two haplotypes was 11 %, suggesting the presence of two distinct genetic groups in Korea. Although the population of Busan, Okchon, Wonju, and Gangneung was identified as a single haplotype, but that of Suwon was occupied by both hapotypes. Considering sequence divergence of other insect species occurring in Korea, the divergence estimate found between the two haplotypes seems to be too large to be considered as identical species. This result may suggest that the two differentiated haplotypes found in this study may reflect the previously reported two ecological types found in Suwon, Korea. To further understand the genetic divergence of the two phylogenetic groups, analysis of more variable regions of G. orientalis genome is required.

• Animal cells and systems
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• v.3 no.3
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• pp.303-309
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• 1999

Inter- and intraspecific genetic relationships between Rana amurensis from Korea and Russia and other brown frogs were investigated by nucleotide sequence of a 504 base pair (bp) fragment of the mitochondrial cytochrome b gene. Nucleotide sequence similarities among Korean populations of R. amurensis ranged from 99.6% to 97.6% and 98.8% within Russian populations. The nucleotide sequence similarity between Korean and Russian R. amurensis ranged from 86.9% to 85.5%. Based on Kimura-2-parameter distance, the sequence divergence between R. amurensis from Korea and Russia was 16.18% and 18.04% among other related brown frogs. interspecific sequence divergences among R. amurensis and other related brown frogs diverged by 20.3%. Using an estimate of 2-4% mitochondrial DNA sequence divergence per million years, Korean and Russian R. amurensis diverged about 8 to 4 million years ago (Mya) and other brown frogs diverged about 9 to 5 Mya from ancestral frogs and distributed from North Asia to Sakhalin in a short time. In the neighbor-joining and UPGMA tree R. amurensis was clustered into two groups with Korean and Russian populations and the other brown frogs were grouped separately with diverged trichotomous clusters (R. dybowskii and R. pirica, R. okinavana and R. tsushimensis, and R. japonica and R. longicrus).

• International Journal of Industrial Entomology and Biomaterials
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• v.31 no.2
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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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• v.23 no.1
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• pp.155-166
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• 2011

The leaf beetle, $Chrysolina$ $aurichalcea$ (Coleoptera: Chysomelidae), is a pest damaging plants of Compositae. In order to understand the genetic diversity and geographic variation we sequenced a portion of mitochondrial COI gene (658 bp) and complete nuclear internal transcribed spacer 2 (ITS2) of the species collected from seven Korean localities. A total of 17 haplotypes (CACOI01~CACOI17), with the maximum sequence divergence of 3.04% (20 bp) were obtained from COI gene sequence, whereas 16 sequence types (ITS2CA01~ITS2CA16), with the maximum sequence divergence of 2.013% (9 bp) were obtained from ITS2, indicating substantially larger sequence divergence in COI gene sequence. Phylogenetically, the COI gene provided two haplotype groups with a high nodal support (${\geq}87%$), whereas ITS2 provided only one sequence type group with a high nodal support (${\geq}92%$). The result of COI gene sequence may suggest the presence of historical biogeographic barriers that bolstered genetic subdivision in the species. Different grouping pattern between COI gene and ITS2 sequences were interpreted in terms of recent dispersal, reflected in the ITS2 sequence. Finding of unique haplotypes and sequence types only from Beakryeng-Islet population was interpreted as an intact remnant of ancient polymorphism. As more samples are analyzed using further hyper-variable marker, further fruitful inference on the geographic contour of the species might be available.

• Communications for Statistical Applications and Methods
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• v.27 no.3
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• pp.385-395
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• 2020

We present a new maximum likelihood approach to estimate demographic history using genomic data sampled from two populations. A demographic model such as an isolation-with-migration (IM) model explains the genetic divergence of two populations split away from their common ancestral population. The standard probability model for an IM model contains a latent variable called genealogy that represents gene-specific evolutionary paths and links the genetic data to the IM model. Under an IM model, a genealogy consists of two kinds of evolutionary paths of genetic data: vertical inheritance paths (coalescent events) through generations and horizontal paths (migration events) between populations. The computational complexity of the IM model inference is one of the major limitations to analyze genomic data. We propose a fast maximum likelihood approach to estimate IM models from genomic data. The first step analyzes genomic data and maximizes the likelihood of a coalescent tree that contains vertical paths of genealogy. The second step analyzes the estimated coalescent trees and finds the parameter values of an IM model, which maximizes the distribution of the coalescent trees after taking account of possible migration events. We evaluate the performance of the new method by analyses of simulated data and genomic data from two subspecies of common chimpanzees in Africa.