• ALGAE
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• v.29 no.1
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• pp.15-25
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• 2014

The number of species of non-native and invasive marine algae is growing, with concomitant public concern about native ecosystems and coastlines. Gelidium vagum, recently introduced from northeast Asia to Europe and North America, commonly occurs from the intertidal to subtidal zones in Korea, China, and Japan. To investigate the level of genetic diversity of native populations, we analyzed mitochondrial cox1 and cob from 108 specimens of G. vagum from Korea, China, eastern Russia, including from the Netherlands and USA. The haplotype network of individual and cox1 + cob datasets revealed no genetic structure in local populations, suggesting genetic flow between Korean populations. Our results corroborate a typical pattern of genetic diversity for introduced species, with low levels in introduced populations and high levels in native populations. All haplotypes were shared between the Netherlands and USA, but not between Korea and the Netherlands / USA except cox1. Additional sampling will identify donor populations in native northeast Asian waters. This is the first report of the utility of the mitochondrial coding cob sequences in red algae.

• Journal of Plant Biology
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• v.37 no.2
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• pp.141-149
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• 1994

Levels of genetic diversity, population genetic structure, and gene flow in Hosta yingeri, a herbaceous perennial endemic to Taehuksan, Sohuksan, and Hong Islands, were investigated. Starch gel electrophoresis was conducted on leaves for 101 plants collected from three populations. Although the distribution of thespecies is restricted in the islands, it maintains high levels of genetic variatin; 64% of polymorphic loci in at least one population (Ps), the mean number of alleles per locus (Ap) of 1.92, and the mean effective number of alleles per locus (Aep) of 1.52. Overall, mean genetic diversity (Hep=0.250) was substantially higher than mean estimate for species with very similarlife history traits (0.102). Large populaton size, the persistence of multiple generations within populations, high fecundity, predominantly outcrossing breeding system, large size of pollinator visitation areas may be explanatory factors contributing the higher level of genetic diversity maintained within populations. Analysis of fixation indices showed an overall slight excess of heterozygotes (mean FIS=-0.066) relative to Hardy-Weinberg expectations, which may in part be due to the near self-incompatible breeding system in the species. Significant differences in allele frequencies among populaitns were found for 14 out of 16 polymorphic loci (P<0.05). Slightly more than 80% of the total variation in the species was common to all populations (GST=0.198). As expected, indirect estimate of the number of migrants per generation (Nm=0.45, calculated from mean GST) and nine private alleles found in the three populations indicate that gene movement among three isolated island populations was low.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1047-1052
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• 2004

The genomes of Chinese native chicken populations were screened using microsatellites as molecular markers. A total of, 528 individuals comprisede12 Chinese native chicken populations were typed for 7 microsatellite markers covering 5 linkage groups and genetic variations and genetic distances were also determined. In the 7 microsatellite loci, the number of alleles ranged from 2 to 7 per locus and the mean number of alleles was 4.6 per locus. By using fuzzy cluster, 12 Chinese native chicken populations were divided into three clusters. The first cluster comprised Taihe Silkies, Henan Game Chicken, Langshan Chicken, Dagu Chicken, Xiaoshan Chicken, Beijing Fatty Chicken and Luyuan Chicken. The second cluster included Chahua Chicken, Tibetan Chicken, Xianju Chicken and Baier Chicken. Gushi Chicken formed a separate cluster and demonstrated a long distance when comparing with other chicken populations.

• Fisheries and Aquatic Sciences
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• v.11 no.1
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• pp.36-40
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• 2008

We analyzed the nucleotide sequences of about 500 bp of the mitochondrial NADH dehydrogenase subunit 3 (ND3) gene to estimate the genetic variation of Korean masu salmon (Oncorhynchus masou) populations. DNA samples were collected from 104 river-only specimens and 52 anadromous specimens from three hatcheries and one river. There are no records of artificial release into the river. We amplified the ND3 gene by polymerase chain reaction, targeting areas that included parts of the cytochrome oxidase III gene and the NADH dehydrogenase subunit 4L gene, and defined 14 haplotypes based on 12 variable nucleotide sites in the examined region. Among the haplotypes, ten were specific to river-only specimens within hatchery populations. Haplotype diversity of river-only populations in hatcheries was higher than that of anadromous and wild populations. Pairwise population $F_{ST}$ estimates and neighbor-joining tree analyses inferred that anadromous and river-only populations were distinct. These results suggest that sequence polymorphism in the ND3 region may be a useful marker for analyzing the genetic variation and population structure of masu salmon.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.6
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• pp.776-783
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• 2008

In this study, we investigated the genetic diversity and phylogenetic relationship of six duck populations by employing the genetic polymorphisms of 20 microsatellites. The parameters used in this study included number of alleles, average effective numbers of alleles (E) and average rates of heterozygosity of each population. The results showed that all the microsatellite loci were highly polymorphic except that the locus AJ515896 in Muscovy duck was 0. The average PIC (0.762), average h (0.7843) and average E (5.261) of the six duck populations were all high, indicating that the gene polymorphisms and genetic diversity were high. The test of Hardy-Weinberg equilibrium showed that the six populations in this study were all in Hardy-Weinberg disequilibrium. The F-statistic analysis results showed the range of FST was from 0.0205 (AJ515895) to 0.2558 (AJ515896). The mean FST was 0.0936. Phylogenetic study revealed that Peking duck (Z1 and Z4), Shaoxing duck, Cherry Valley duck and Aobaixing duck were clustered in one group, while the Muscovy duck was clustered in one group alone. The phylogenetic relationships among different populations were in accordance with their breeding history and distribution. Our data suggested that the 20 microsatellite loci were effective markers for analysis of genetic relationships among duck populations.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.157-165
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• 2002

Genetic variations of seven egg white protein loci in 1,112 samples from eight Asian countries (Yunnan province of China, Mongolia, Nepal, Vietnam, Laos, Thailand, Myanmar, Indonesia) and 360 samples from two improved breeds (Isa Brown, Boris Brown) were investigated by using starch gel and polyacrylamide gel electrophoresis. Five egg white protein loci (Ov, $G_3$, $G_2$, $G_1$ and $Tf_{EW}$) were found to be polymorphic in Asian native chicken populations. The proportion of polymorphic loci ($P_{poly}$) and average heterozygosity ($\bar{H}$) of Asian native populations varied from 0.143 to 0.714 and 0.014 to 0.225, respectively, and were higher than those of improved breeds. The subdivision index ($G_{ST}$) value among 18 native chicken populations in Asia is lower (0.0827) than among improved chicken populations (0.1693). This value means that the degree of subdivision among Asian native populations is lower than among improved breeds and gene constitutions among populations in Asia are similar.

• Korean Journal Plant Pathology
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• v.13 no.2
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• pp.100-104
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• 1997

Influence of the moisture content in soils was examined on population variations of soil microbes, including Cylindrocarpon destructans causing root rot of ginseng, in vivo and under the field condition. Fungal populations decreased in soils treated with various moisture contents in vivo as days after the treatment in creased, but there was not a significant difference in the population among other treatments except 135% moisture content (flooding) at 15 weeks after the treatment. In flooded soils populations of total fungi and C. destructans were reduced to 1/10 and 1/50 of initial populations, respectively. There was, however, a little difference in the population of total bacteria or Actinomycetes between before and at 15 weeks after flooding. On the other hand, population variations of bacteria and Actinomycetes were much greater than those of fungi at different intervals after the moisture treatment. Variations of microbial populations in flooded soils under the field condition were similar to those in vivo. Especially, populations of Fusarium and pectolytic bacteria in flooded soils were reduced to 1/100 of populations in nonflooded soils at 170 days after treatment.

• Development and Reproduction
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• v.16 no.1
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• pp.47-51
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• 2012

Genomic DNAs (gDNAs) were isolated from the hard clam ($Meretrix$ $lusoria$, Roding, 1798) populations of Gunsan located in the Yellow Sea of the Korean peninsula. Genetic distances among different individuals of the LSCP (light shell color population) population of the hard clam (lane 1-11), GSCP (grey shell color population) population of the hard clam (lane 12-22) and DSCP (dark shell color population) population of the hard clam (lane 23-33), respectively, were generated using Systat version 10 according to the bandsharing values and similarity matrix. The dendrogram, generated by seven reliable oligonucleotides primers, indicates 3 genetic clusters. LSCP population could be evidently discriminated with the other two populations among three populations. The longest genetic distance (0.801) was found to exist between individuals in the two populations, between individuals' no. 33 of the DSCP population and no. 06 of the LSCP population. The higher fragment sizes (>2,000 bp) are much more observed in the GSCP population. Three hard clam populations can be clearly distinguished, especially, by their morphological characters and PCR-based approach.

• Fisheries and Aquatic Sciences
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• v.12 no.1
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• pp.44-48
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• 2009

Nucleotide sequences of about 500 bp from the 5' end of mitochondrial (mt) DNA Cytochrome Oxidase I (COI) were analyzed to estimate the genetic variation between wild and cultured populations of the ascidian Halocynthia roretzi from two sites along the coast of Korea. A total of 25 haplotypes were defined by 21 variable nucleotide sites in the examined COI region. Genetic diversity (haplotype diversity and nucleotide divergence) of wild populations was higher than that of the cultured population. These data suggest that reduced genetic variation in the cultured population may have results from bottleneck effect caused by the use of a limited number of parental stock and pooling of gametes for fertilization. Pairwise population $F_{ST}$ estimates inferred that wild and cultured populations were genetically distinct. The combined results suggest that sequence polymorphism in the COI region would be preferable for estimating the genetic diversity of ascidian populations.

• Korean Journal of Health Education and Promotion
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• v.2 no.1
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• pp.97-114
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• 2000

Minority populations in the United States have a higher prevalence of non-insulin-dependent diabetes mellitus (NIDDM) and more persons die of the disease than white persons. This study was to review and compare risk factors and prevalence rates of NIDDM in African Americans, Hispanic s, Korean Americans and Native Americans in the United States. The risk factors of NIDDM, including family history of diabetes, obesity, physical inactivity, diet and age, were reviewed in the minority populations. Risk factors such as obesity, physical inactivity and family history of diabetes occurred to a greater extent in some minority populations than in the white population. Diabetes should be treated as a public health problem for minority populations. Due to the increase of older populations and the increased prevalence of obesity and sedentariness, NIDDM in minorities is nearing epidemic proportions. Good diet and regular exercise can reduce the incidence of NIDDM but an understanding of the cultural aspects of diabetes is imperative in order to provide adequate community health education programs because those programs involve diet and behavior changes, characteristics that are often culturally determined. In summary, it is important to plan a community health education program targeted on NIDDM in a culturally adapted manner that will be received with both comprehension and acceptability. In particular, the program for high-risk populations should be stressed so to prevent diabetes. Preventive approaches to diabetes should be considered because they can be both therapeutic and cost effective.