• ALGAE
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• v.26 no.1
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• pp.21-32
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• 2011

Studies of the red algal genus Bostrychia over the last 15 years have made it a model system for many evolutionary processes within red algal species. The combination of newly developed, or first employed methods, in red algal species studies has made Bostrychia a pioneer genus in intraspecific studies. Bostrychia was the first genus in which a mitochondrial marker was used for intraspecific red algal phylogeny, and the first for which a 3-genome phylogeny was undertaken. The genus was the first red alga used to genetically show maternal plastid and mitochondria inheritance, and also to show correlation between cryptic species (genetically divergent intraspecific lineages) and reproductive incompatibility. The chemotaxonomic use, and physiological function of osmolytes, has also been extensively studied in Bostrychia. Our continuous studies of Bostrychia also highlight important aspects in algal species studies. Our worldwide sampling, and resampling in certain areas, show that intensive sampling is needed to accurately assess the genetic diversity and therefore phylogeographic history of algal species, with increased sampling altering evolutionary hypotheses. Our studies have also shown that long-term morphological character stability (stasis) and character convergence can only be correctly assessed with wide geographic sampling of morphological species. While reproductive incompatibility of divergent lineages supports the biological species nature of these lineages, reproductive incompatibility is also seen between isolates with little genetic divergence. It seems that reproductive incompatibility may evolve quickly in red algae and the unique early stages of fertilization (e.g., gametes covered by walls, active movement of spermatium nuclei to the distant egg nucleus), also well investigated in Bostrychia,. may be key to our understanding of this process.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.645-652
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• 2007

The origin of domestic donkeys in China has been controversial. To clarify the origin of Chinese domestic donkeys, we investigated the partial mitochondrial D-loop sequences of 126 samples from 12 native breeds. The results revealed two mitochondrial origins, lineage Somali and lineage Nubian of African wild ass detected in Chinese domestic donkeys. Lineage Somali was predominant in Chinese domestic donkey breeds. The pattern of genetic variation in ass mtDNA D-loop sequences indicated that the two lineages Somali and Nubian from China had undergone population expansion events. In a combined analysis of lineages Somali and Nubian between previously published sequences from other countries/regions and sequences of Chinese domestic donkeys, the results indicated that the two lineages of Chinese domestic donkeys were from Africa and supported the African maternal origins of Chinese domestic donkeys. There was no obvious geographical structure in Chinese domestic donkey breeds, but the population showed abundant mtDNA diversity. The spread routes of Chinese domestic donkeys were also discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.471-476
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• 2007

Little is known about the origin and genetic diversity of swamp buffaloes in China. To obtain more knowledge on genetics of the water buffalo in China, the complete mitochondrial D-loop sequences of 30 samples from 6 native types were investigated. The results revealed 12 mitochondrial haplotypes with 50 polymorphic sites. Among these polymorphic sites, there were 49 transitions and 1 transversion. The average nucleotide diversity and haplotype diversity estimated from mtDNA D-loop region in 6 Chinese water buffalo types were 0.00684 and 0.798, respectively, showing rather abundant mitochondrial genetic diversity. The Neighbor-Joining (NJ) tree of mtDNA of Chinese water buffaloes was constructed according to the 12 haplotypes. The NJ tree indicated two lineages being designated lineage A and lineage B, in which lineage A was predominant, and lineage B was at low frequency. The new lineage B was first discovered and defined in 6 Chinese water buffalo types. These results showed that two different maternal lineages were involved in the origin of domestic swamp buffaloes in China and the lineage B was probably an introgression from Southeast Asian buffaloes.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.257-257
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• 2022

Late blight, caused by the hemibiotrophic oomycete pathogen Phytophthora infestans, has been the most important disease limiting potato production worldwide. P. infestans undergo major population shifts in agricultural systems via the successive emergence and migration of asexual lineages. The phenotypic and genotypic bases of these selective sweeps are largely unknown but management strategies need to adapt to reflect the changing pathogen population. Here, we used molecular markers to divide the 86 South Korea isolates into six clonal lineages: KR_1_A1, KR_2_A2, SIB-1, US-11, SIB-1 like, and KR-2 like. We documented the emergence of a new lineage, termed SIB-1 like, and KR-2 like, and their rapid replacement of other lineages to exceed 35% of the pathogen population across South Korea. Genome analyses of the Korean P. infestans populations revealed extensive genetic polymorphism, particularly in effector genes. Importantly, SIB-1 like isolates carry an intact Avr8 effector gene that triggers resistance in potato carrying the corresponding R immune receptor gene R8 cloned from Solarium demissum. These findings point toward a strategy for deploying genetic resistance to mitigate the impact of the SIB-1 like lineage and illustrate how pathogen population monitoring, combined with genome analysis, informs the management of devastating disease epidemics. Further study is being done on pathogenicity of the SIB-1 like isolates on cultivated potatoes and changes in expression patterns of disease effector genes within the SIB-1 like isolates

• Journal of Life Science
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• v.23 no.1
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• pp.24-30
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• 2013

The purpose of this study was to identify genetic polymorphisms of the mitochondrial cytochrome b (mtDNA cyt b) gene in Korean black (KB) cattle breed and to analyze the genetic relationship between the KB and other breeds. We determined the complete sequence of the mtDNA cyt b gene in 38 KB cattle. We also analyzed their genetic diversity, and phylogenetic analysis was performed by comparison with Korean cattle (KC, called Hanwoo) and breeds from China and Japan. A nucleotide substitution was detected in the KB cattle, and two haplotypes were defined. In the neighbor-joining (NJ) tree, the haplotypes of KB were located in Bos taurus lineage with those of KC, Japanese black (JB), Yanbian and Zaosheng breeds. However, the haplotypes of Chinese breeds, excluding Yanbian and Zaosheng, were separated into B. taurus and B. indicus lineages. In the NJ tree of breeds based on Dxy genetic distances, Chinese breeds mixed with B. taurus and B. indicus lineages were located between B. indicus and B. taurus lineages. KB was contained within B. taurus lineage and was determined to be genetically more closely related to two Chinese (Yanbian and Zaosheng) breeds than to KC and JB. The haplotype distribution and the results of the phylogenetic analysis suggest that KB and KC have genetic differences in their mtDNA cyt b gene sequences.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.155-161
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• 2011

In this study, mitochondrial DNA (mtDNA) sequence polymorphism was used to assess genetic diversity of nine Vietnamese local chicken breeds. In addition, two Chinese breeds kept in Vietnam were included in the analysis for comparison. A 455-bp fragment of the mtDNA D-loop region was sequenced in 222 chickens of these 11 breeds. As reference, a skeleton was constructed based on chicken mtDNA sequences taken from the Genbank. Haplotypes of the nine Vietnamese local and two Chinese breeds were aligned together with these sequences. The Vietnamese and Chinese breeds showed a high degree of variability. In total, 37 haplotypes were identified in the chicken breeds studied forming eight clades. Thereby, the majority of individuals of the two Chinese breeds grouped together in one clade which is assumed to have its roots in the Indian subcontinent. Although the Vietnamese chicken breeds were distributed across all eight clades, most of them clustered in three main clades. These results suggest that the Vietnamese domestic chickens have originated from multiple maternal lineages, presumably from Yunnan and adjacent areas in China, South and Southwest China and/or surrounding regions (i.e. Vietnam, Burma, Thailand, and India).

• Journal of Sericultural and Entomological Science
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• v.39 no.2
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• pp.119-133
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• 1997

Isozyme was used to characterize general protein patterns of genetic relationships among 303 silkworm stocks preserved in National Sericultural and Entomology Research Institute, RDA. Six isozymes (esterase, acid phosphatase, alkaline phosphatase, amylase, glucose-6-phosphate dehydrogenase and sucrase) from hemolymph, midgut, and digestive juice were employed to construct dendograms(UPGMA method) using a polycrylamide gel electrophoresis. A cluster analysis revealed four major group, which were divided into several subgroups within each group, contained assemglages of Japanese and Chinese races. Especially, genetic differentiation in the first and second group was greatest rather than within Japanese and Chinese races repectively and was concordant with the hypothesis of phyletic sorting of initial variability in China many years ago. Hypothesized recent introgression between groups was also plausible, but the eviednce suggested bidirectional gene flow between the Chinese and the Japnaese lineages. Interpreting the results in light of evidence from the current study, the genetic diversity and relationship showed in Korean silkworm race, Hansammyun reflected early and independent evolution from the Chinese ancestor, limited addition of new variability and phyletic sorting within Korean peninsula more than 4,000 years.

• Korean Journal of Veterinary Service
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• v.33 no.4
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• pp.353-359
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• 2010

Nucleotide sequences of mitochondrial DNA (mtDNA) of 19 leopard cats (Prionailurus bangalensis euptilura) obtained from Seoul grand park zoo in South Korea were determined for analysing genetic diversity. In the leopard cats, 3 haplotypes of the partial cytochrome b sequences (603 base-pairs, bp) were identified. Haplotypes obtained from those genes showed existences of at least 3 maternal lineages of leopard cats in Korea. Tamura-Nei nucleotide distance among 3 haplotypes were 0.00. Molecular phylogenetic tree showed the similar clustering of haplotypes for genes. Meanwhile, no individual variations within the leopard cats in S. Korea. Genetic surveillance system of leopard cats in S. Korea is warranted for maintaining biological conservation.

• ALGAE
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• v.34 no.3
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• pp.229-236
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• 2019

Despite the abundance of seaweeds from Ulleungdo Island, genetic diversity and distribution of edible brown algae from the island remain unstudied. We analyzed mitochondrial cox3 sequences from 86 specimens collected in the island and from the nearby Korean Peninsula. Our cox3 phylogeny for the first time confirmed the occurrence of fives species from Ulleungdo Island; Petalonia binghamiae, P. fascia, Planosiphon zosterifolius, and two cryptic species previously identified as Scytosiphon lomentaria. P. binghamiae was relatively homogeneous with three haplotypes. P. fascia comprised four haplotypes, which were grouped into two genetic lineages. S. lomentaria was heterogeneous with nine haplotypes and was divided into two cryptic species; one species clustered with taxa from cold waters while the other clustered with taxa from temperate and cold waters. Low genetic diversity in P. binghamiae while high genetic diversity in S. lomentaria from Ulleungdo Island are comparable to patterns observed from other species from the Korean peninsula. Ulleungdo Island, although small in size, is an ideal field laboratory to investigate genetic diversity and distributions of economic marine algae.

• Molecules and Cells
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• v.25 no.4
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• pp.523-530
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• 2008

In this study, the species composition and population genetic properties of the sea slater, Ligia, in South Korea were investigated using mitochondrial and nuclear gene sequences. Two groups of sea slaters, genetically isolated from each other, a Western Group (WG) and an Eastern Group (EG) were identified. These groups exhibited considerable genetic divergence from Ligia exotica, previously recorded as a species inhabiting this country. These results indicate that there may be two species of Ligia in South Korea, but there is a small probability that both groups are L. exotica. A comparison of their genetic properties indicates that WG has a higher effective population size than EG, and that EG may have experienced a recent expansion, implying that it has a shorter history in South Korea than WG. These findings suggest that the South Korean sea slater populations may have been established as a result of several colonization events that can be traced on a continental scale by phylogeographic studies of sea slaters.