• The Journal of the Korean Society for Microbiology
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• v.21 no.2
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• pp.171-179
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• 1986

The HLA class II region encodes a series of polymorphic glycoproteins that form cell surface heterodimers each consisting of one $\alpha$ and one $\beta$ chain. Thess class II molecules are encoded by genes clustered within three loci. DP, DQ, and DR are functfonally implicated as regulatory signals in intercellular communication during the immune resposes. The phenotypic hallmark of the HLA complex is a high degree of structural and functional polymorphism. Detailed analysis. of such polymorphisms should aid in understanding the molecular basis for associations between HLA and diseases. We have used techniques of restriction enzyme fragment analysis by Southern blotting to investigate polymorphisms associated with DQ $\beta$ class II genes on haplotypes expressing the HLA-DR4 and -DQw3 specificities. The endonucleases Hind III and Bam HI were used to identify a specific DQ $\beta$ genomic polymorphism that precisely corrresponds with the reactivity of a monoclonal antibody A-10-83, previously shown to define a serologic split of DQw3. This study identifies two allelic DQ va. riants. DQw3.1 and DQw3.2. We used these specific genotypic markers to investigate the genomic basis of the association of DR4 with insulin-dependent diabetes mellitus(IDDM) and seropositive juvenile rheumatoid arthritis(JRA). The DR4 positive IDDM demonstrate the predominant expression of DQw3.2 and the very rare expression of DQw3.l. However, in haplotype matched siblings from two IDDM families, all of the DR4 positive siblings display a IDDM-associated DQw3.2 allele. Thus, both affected and healthy individuals can carry the same haplotypes and genomic markers, demonstrating that thess specific allelic variants are genetic elements that indicate a increased risk of IDDM but are not in fact disease specific. We contrasted this result with a similar analysis of patients with another DR4-associated disease, JRA. In contrast to the preponderance of the DQw3.2 allele in IDDM, the JRA patients expressed either the DQw3.1 or the DQw3.2 allele and sometimes both, without apparent association with disease expession. The different genomic markers reported here within HLA-DQ region potentially an analysis of HLA-associated function and disease susceptibility.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.4
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• pp.334-340
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• 2001

Two different types of molecular markers, simple sequence repeat (SSR) and single nucleotide polymorphism (SNP), were used to measure genetic diversity among five Korean, eight Thai, and three wild soybeans. For SSR analysis, a total of 20 markers were surveyed to detect polymorphisms. For SNP analysis, four primers were designed from consensus sequence regions on disease resistance protein homolog genes, and used to amplify the genomic region. The PCR products were sequenced. A number of polymorphic SSR and SNP bands were scored on all genotypes and their genetic similarity was measured. Clustering analysis was performed independently on both types of markers. Clustering based on SSR markers separated the genotypes into three main groups originated from Korea, Thailand, and wild soybeans. On the other hand, two main groups were classified using SNP analysis. It seemed that SSR was more informative than SNP in this study. This may be due to the fact that SNP was surveyed on the smaller genomic region than SSR. Grouping based on the combined data of both markers revealed similar results to that of SNP rather than that of SSR. This might be due to the fact that more loci from SNP were considered to measure genetic relatedness than those from the SSR.

• Journal of Life Science
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• v.20 no.6
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• pp.819-824
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• 2010

Genus Phyllostachys is a long-lived woody species primarily distributed throughout South East Asia. Many species of this genus has been regarded as medically and ecologically important in the world. We evaluated representative samples of the four taxa with RAPD to estimate genetic relationships within the genus Phyllostachys. The percentages of polymorphic loci were 8.9-33.3% at the species level. P. bambusoides was found to show lower genetic diversity (H=0.018) than other species. Total genetic diversity ($H_T$) was 0.315, genetic diversity within populations ($H_S$) was 0.043, the proportion of total genetic diversity partitioned among populations ($G_{ST}$) was 0.659 and the gene flow (Nm) was 0.0263. As some Korean populations were isolated and patchily distributed, they exhibited low levels of genetic diversity. The four taxa of the genus Phyllostachys analyzed were distinctly related to a monophyletic. P. nigra var. henonis. Stapf was found to be more closely related to P. pubescens than to P. nigra. P. bambusoides was quite distinct from the remaining species.

• Korean Journal of Medicinal Crop Science
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• v.10 no.1
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• pp.5-11
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• 2002

The study of genetic diversity was carried out in Atractylodes japonica $K_{OIDZ}$. Although this species has been regarded as medically important one, there is no report on population structure in Korea. Starch gel electrophoresis was used to investigate the allozyme variation and genetic structure of eight Korean populations of this species. Of the 15 genetic loci surveyed, nine (60.0%) was polymorphic in at least one population. Genetic diversity was high at the species level $(H_{es}=0.144)$, whereas, that of the population level was relatively low $(H_{ep}=0.128)$. Nearly 87% of the total genetic diversity in A. japonica was apportioned within populations. The sexual reproduction, high fecundity, and perennials are proposed as possible factors contributing to high genetic diversity. The indirect estimated of gene flow based on Gst was 1.69.

• Korean Journal of Medicinal Crop Science
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• v.18 no.2
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• pp.86-92
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• 2010

The polymorphism and the genetic relationships among 32 genetic resources of genus Nelumbo from Korea, Japan, China, USA, India, Thailand and Gabong were thoroughly investigated and extensively examined using ISSR markers. Out of 103 loci detected overall, 94 were identified to be polymorphic with a rate of 91.2%. The genetic similarity matrix revealed a wide range of variability among the 32 accessions, spanning from 0.227 to 0.833. The study findings indicate that the Nelumbo accessions have a high genetic diversity, and accordingly carry a germplasm qualifying as good genetic resources for cross breeding. According to the clustering analysis, different subspecies, N. nucifera and N. lutea, were divided into independent groups and all of the N. nucifera accessions could be classified into five categories. Compared to RAPD analysis, ISSR method showed a clearer picture of polymorphism among the accessions and exhibited a definite distinction even among the subspecies. In this respect, ISSR analysis is considered to be more effective in differentiating the accessions and subspecies of the genus Nelumbo than RAPD test.

• Mycobiology
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• v.47 no.2
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• pp.200-206
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• 2019

Allelic differences in A and B mating-type loci are a prerequisite for the progression of mating in the genus Pleurotus eryngii; thus, the crossing is hampered by this biological barrier in inbreeding. Molecular markers linked to mating types of P. eryngii KNR2312 were investigated with randomly amplified polymorphic DNA to enhance crossing efficiency. An A4-linked sequence was identified and used to find the adjacent genomic region with the entire motif of the A locus from a contig sequenced by PacBio. The sequence-characterized amplified region marker $7-2_{299}$ distinguished A4 mating-type monokaryons from KNR2312 and other strains. A BLAST search of flanked sequences revealed that the A4 locus had a general feature consisting of the putative HD1 and HD2 genes. Both putative HD transcription factors contain a homeodomain sequence and a nuclear localization sequence; however, valid dimerization motifs were found only in the HD1 protein. The ACAAT motif, which was reported to have relevance to sex determination, was found in the intergenic region. The SCAR marker could be applicable in the classification of mating types in the P. eryngii breeding program, and the A4 locus could be the basis for a multi-allele detection marker.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.4
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• pp.191-198
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• 2022

Natural habitats of the Korean long-tailed goral (Naemorhedus caudatus) have been fragmented by anthropogenic activities in South Korea in the last decades. Here, the individual identity, genetic variation, and population differentiation of the endangered species were examined via the multiple-tube approach using a non-invasive genotyping method. The average number of alleles was 3.16 alleles/locus for the total population. The Yanggu population (1.66) showed relatively lower average number of alleles than the Inje population (3.67). Of the total 19 alleles, only seven (36.8%) alleles were shared by the two populations. Using five polymorphic out of six loci, four and six different goral individuals from the captive Yanggu (n=24) and the wild Inje (n=28) population were identified, respectively. The allele distribution was not identical between the two populations (Fisher's exact test: P<0.01). A considerably low migration rate was detected between the two populations (no. of migrants after correction for size=0.294). Additionally, the F statistics results indicated significant population differentiation between them, however, quite low (F_ST=0.327, P<0.01). The posterior probabilities indicated that the two populations originated from a single panmictic population (P=0.959) and the assignment test results designated all individuals to both populations with nearly equal likelihood. These could be resulted from moderate population differentiation between the populations. No significant evidence supported recent population bottleneck in the total Korean goral population. This study could provide us with useful population genetic information for conservation and management of the endangered species.

• Animal Bioscience
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• v.35 no.9
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• pp.1314-1326
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• 2022

Objective: Alongside the rise of animal-protection awareness in Taiwan, the public has been paying more attention to dog genetic deficiencies due to inbreeding in the pet market. The goal of this study was to isolate novel microsatellite markers for monitoring the genetic structure of domestic dog populations in Taiwan. Methods: A total of 113 DNA samples from three dog breeds-beagles (BEs), bichons (BIs), and schnauzers (SCs)-were used in subsequent polymorphic tests applying the 14 novel microsatellite markers that were isolated in this study. Results: The results showed that the high level of genetic diversity observed in these novel microsatellite markers provided strong discriminatory power. The estimated probability of identity (P_(ID)) and the probability of identity among sibs (P_(ID)sib) for the 14 novel microsatellite markers were 1.7×10^-12 and 1.6×10^-5, respectively. Furthermore, the power of exclusion for the 14 novel microsatellite markers was 99.98%. The neighbor-joining trees constructed among the three breeds indicated that the 14 sets of novel microsatellite markers were sufficient to correctly cluster the BEs, BIs, and SCs. The principal coordinate analysis plot showed that the dogs could be accurately separated by these 14 loci based on different breeds; moreover, the Beagles from different sources were also distinguished. The first, the second, and the third principal coordinates could be used to explain 44.15%, 26.35%, and 19.97% of the genetic variation. Conclusion: The results of this study could enable powerful monitoring of the genetic structure of domestic dog populations in Taiwan.

• Animal Bioscience
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• v.36 no.10
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• pp.1508-1516
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• 2023

Objective: To carry out a comprehensive production planning of the existing Rongchang pig population from both environmental and genetic aspects, and to establish a closed population with stable genetic diversity and strict pathogen control, it is necessary to fully understand the genetic background of the population. Methods: We genotyped 54 specific pathogen free (SPF) Rongchang pigs using the Zhongxin-1 Porcine Breeding Array PLUS, calculated their genetic diversity parameters and constructed their families. In addition, we also counted the runs of homozygosity (ROH) of each individual and calculated the value of inbreeding coefficient based on ROH for each individual. Results: Firstly, the results of genetic diversity analysis showed that the effective population size (N_e) of this population was 3.2, proportion of polymorphic markers (P_N) was 0.515, desired heterozygosity (H_e) and observed heterozygosity (H_o) were 0.315 and 0.335. H_o was higher than H_e, indicating that the heterozygosity of all the selected loci was high. Secondly, combining the results of genomic relatedness analysis and cluster analysis, it was found that the existing Rongchang pig population could be divided into four families. Finally, we also counted the ROH of each individual and calculated the inbreeding coefficient value accordingly, whose mean value was 0.09. Conclusion: Due to the limitation of population size and other factors, the genetic diversity of this Rongchang pig population is low. The results of this study can provide basic data to support the development of Rongchang pig breeding program, the establishment of SPF Rongchang pig closed herd and its experimental utilization.

• Plant Breeding and Biotechnology
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• v.7 no.3
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• pp.186-199
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• 2019

We selected 68 Chinese maize inbred lines to understand the genetic diversity, population structure, and marker-trait associations for eight agronomic traits and 50 simple sequence repeats (SSRs) markers. In this study, effective traits, such as days of anthesis (DA), days of silking (DS), ear height (EH), plant to ear height ratio (ER), plant height (PH), and leaf width (LW) were divided into PC1 and PC2 by PCA analysis for maize inbred lines. Genetic diversity analysis revealed a total of 506 alleles at 50 SSR loci. The mean number of alleles per locus was 10.12. The averages of genetic diversity (GD) and polymorphic information content (PIC) values were 0.771 and 0.743, respectively. Based on a membership probability threshold of 0.80, the population structure revealed that the total inbred lines were divided into three major groups with one admixed group. A marker-trait association using Q + K MLM showed that nine SSR markers (bnlg1017, umc2041, umc2400, bnlg105, umc1229, umc1250, umc1066, umc2092, and umc1426) were related with seven agronomic traits. Among these SSR markers, eight SSR markers were associated with only one agronomic trait (DA, DS, ER, LL, LW, PH, and ST), whereas one SSR marker (umc1229) was associated with two agronomic traits (DA and ST). These results will help in optimizing the choice of inbred lines for cross combinations, as well as in selecting markers for further maize breeding programs.