• ALGAE
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• v.32 no.2
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• pp.155-160
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• 2017

Red rot disease has caused a major decline in Pyropia (Nori) crop production in Korea, Japan, and China. To date, only Pythium porphyrae (Pythiales, Oomycetes) has been reported as the pathogen causing red rot disease in Pyropia yezoensis (Rhodophyta, Bangiales). Recently, Pythium chondricola was isolated from the infected blades of Py. yezoensis during molecular analyses using the mitochondrial cox1 region. In this study, we evaluated the pathogenicity of P. chondricola as an algal pathogen of Py. yezoensis. Moreover, a new cox2 marker was developed with high specificity for Pythium species. Subsequent to re-inoculation, P. chondricola successfully infected Py. yezoensis blades, with the infected regions containing symptoms of red rot disease. A novel cox2 marker successfully isolated the cox2 region of Pythium species from the infected blades of Py. yezoensis collected from Pyropia aquaculture farms. cox2 sequences showed 100% identity with that of P. chondricola (KJ595354) and 98% similarity with that of P. porphyrae (KJ595377). The results of the pathogenicity test and molecular analysis confirm that P. chondricola is a new algal pathogen causing red rot disease in Pyropia species. Moreover, it could also suggest the presence of cryptic biodiversity among Korean Pythium species.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1510-1517
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• 2008

Expresssed sequence tag (EST) analysis was developed from three cDNA libraries constructed from cells of the digestive tract, gonad, and liver of sea squirt. Randomly selected cDNA clones were partially sequenced to generate a total of 922 ESTs, in which 687 unique ESTs were identified respectively. Results of BLASTX search showed that 612 ESTs (89%) have homology to genes of known function whereas 75 ESTs (11%) were unidentified or novel. Based on the major function of their encoded proteins, the identified clones were classified into ten broad categories. We also identified several kinds of immune-related genes as identifying novel genes. Sequence analysis of ESTs revealed the presence of microsatellite-containing genes that may be valuable for further gene mapping studies. The accumulation of a large number of identified cDNA clones is invaluable for the study of sea squirt genetics and developmental biology. Further studies using cDNA microarrays are needed to identify the differentially expressed transcripts after disease infection.

• The Korean Journal of Malacology
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• v.30 no.3
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• pp.197-210
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• 2014

Single nucleotide polymorphisms (SNPs) are widely acknowledged as the marker of choice for many genetic and genomic applications because they show co-dominant inheritance, are highly abundant across genomes and are suitable for high-throughput genotyping. Here we evaluated the applicability of SNP markers developed from Crassostrea gigas and C. virginica expressed sequence tags (ESTs) in closely related Crassostrea and Ostrea species. A total of 213 putative interspecific level SNPs were identified from re-sequencing data in six amplicons, yielding on average of one interspecific level SNP per seven bp. High polymorphism levels were observed and the high success rate of transferability show that genic EST-derived SNP markers provide an efficient method for rapid marker development and SNP discovery in closely related oyster species. The six EST-SNP markers identified here will provide useful molecular tools for addressing questions in molecular ecology and evolution studies including for stock analysis (pedigree monitoring) in related oyster taxa.

• Molecules and Cells
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• v.24 no.1
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• pp.60-68
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• 2007

Microsatellites, also called simple sequence repeats (SSR), are very useful molecular genetic markers commonly used in crop breeding, species identification and linkage analysis. In the present study, we constructed a microsatellite-enriched genomic library of Panax ginseng, and identified 251 novel microsatellite sequences. Tri-nt repeat units were the most abundant (46.6%), followed by di-nt repeats (35.5%). The $(AG)_n$ motif was most common (23.1%), followed by the $(AAC)_n$ motif (22.3%). From the genotyping of 94 microsatellites using marker-specific primer sets, we identified 11 intraspecific polymorphic markers as well as 14 possible interspecific polymorphic markers differing between P. ginseng and P. quinquefolius. The exact allele structures of the polymorphic markers were determined and the alleles were named. This study represents the first report of the bulk isolation of microsatellites by screening a microsatellite-enriched genomic library in P. ginseng. The microsatellite markers could be useful for linkage analysis, genetic breeding and authentication of Panax species.

• Parasites, Hosts and Diseases
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• v.61 no.1
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• pp.78-83
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• 2023

The use of an effective antimalarial drug is the cornerstone of malaria control. However, the development and spread of resistant Plasmodium falciparum strains have placed the global eradication of malaria in serious jeopardy. Molecular marker analysis constitutes the hallmark of the monitoring of Plasmodium drug-resistance. This study included 96 P. falciparum PCR-positive samples from southern Somalia. The P. falciparum chloroquine resistance transporter gene had high frequencies of K76T, A220S, Q271E, N326S, and R371I point mutations. The N86Y and Y184F mutant alleles of the P. falciparum multidrug resistance 1 gene were present in 84.7 and 62.4% of the isolates, respectively. No mutation was found in the P. falciparum Kelch-13 gene. This study revealed that chloroquine resistance markers are present at high frequencies, while the parasite remains sensitive to artemisinin (ART). The continuous monitoring of ART-resistant markers and in vitro susceptibility testing are strongly recommended to track resistant strains in real time.

• Journal of Life Science
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• v.25 no.7
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• pp.839-848
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• 2015

A molecular marker is a molecule contained within a sample taken from an organism or other matter. The development of molecular techniques for genetic analysis has led to a great contribution to our knowledge of plant genetics and our understanding of the structure and behavior of various genomes in plants. Recently, functional molecular markers have been developed to detect the presence of major genes from the analysis of pedigreed data in absence of molecular information. DNA markers have developed into many systems based on different polymorphism-detecting techniques or methods such as RFLP, AFLP, RAPD, SSR, SNP, etc. A new class of very useful DNA markers called genic molecular markers utilizing the ever-increasing archives of gene sequence information being accumulated under the EST sequencing projects on a large number of plant species. Functional markers are derived from polymorphic sequences, and are more likely to be involved in phenotypic trait variation. Based on this conceptual framework, the marker systems discussed below are all (gene)-targeted markers, which have the potential to become functional. These markers being part of the cDNA/EST-sequences, are expected to represent the functional component of the genome i.e., gene(s), in contrast to all other random DNA based markers that are developed/generated from the anonymous genomic DNA sequences/domains irrespective of their genic content/information. Especially I sited Poczai et al’ reviews, advances in plant gene-targeted and functional markers. Their reviews may be some useful information to study molecular markers in plants.

• Journal of Life Science
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• v.20 no.3
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• pp.381-387
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• 2010

To find offspring of Jeju Black cattle (JBC) produced by embryo transfer (ET) and artificial insemination (AI), a molecular genetic study was carried out in candidate cattle populations collected from cattle farms in Jeju Island, Korea. The genetic marker set was composed of 11 ISAG microsatellite (MS) markers, 11 SAES MS markers selected by our preliminary analysis for population diversity of JBC and two major coat color related genes: MC1R and ASIP. The results showed a combined non-exclusion probability for first parent (NE-P1) that was higher than that recommended by ISAG (above 0.9995), and a combined non-exclusion probability for sib identity of $5.3{\times}10^{-10}$. Parentage analysis showed that the cases identified the candidate's father only (77.0%), mother only (54.0%), and both parents (40.5%) in the candidate offspring population. The ET and AI calves were identified as 14.7% in the in vitro fertilized eggs provided and 32.4% in total population, respectively. However, the result from ISAG marker analysis showed 3 identical allele-combinations in 7 calves, and that from ISAG/SAES MS marker combination also showed 1 identical allele-combination in 2 calves. Data from MS and coat-color gene analyses provided information for complete identification of all animals tested. Because the present JBC population was mostly bred using small nuclear founders through bioengineering techniques such as AI and ET, the genetic diversity levels obtained from MS analysis in the JBC population were relatively lower than those of other cattle populations, including Hanwoo. The results suggested that the more efficient marker combinations, including coat color related genotypes, should be studied and used for constructing a system for identification and molecular breeding of JBC as well.

• Animal cells and systems
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• v.2 no.1
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• pp.81-86
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• 1998

Recent identification and characterization of plant homeobox genes suggest that they play important roles in morphogenetic events. OSH1, one of the rice homeobox genes, is thought to be related to organ development since the changes of OSH1 gene expression cause morphological abnormalities of leaves by the ectopic expression and is expressed during early embryogenesis. In this experiment, the expression pattern of OSH1 was analyzedinmutants by in situ hybridization, and OSH1's potential as a molecular marker was explored. Region-specific expression of OSH1 during early embryogenesis shows that OSH1 could be used as a molecular marker for characterizing embryo mutants. Although several organless and shootless mutants showed normal expression of OSM1, some mutants exhibited abnormal expression patterns. In a minute organless cle1-1 embryo whose epidermis resembled morphologically the epithelium of scutellum, OSH1 expression was limited to a small basal region. This expression pattern suggests the gross deletion of the basal part. In a radicleless mutant, odm115, OSH1 expression was detected in a basal region instead of subcentral region of the ventral side. Together with other characteristics (short embryo and normal adventitious roots), odm115 was estimated to be derived from the deletion of basal region. Among five shootless mutants, three showed normal expression of OSH1. In the shl2 embryo, no expression of OSH1 was observed. In the shl1 embryo, however, OSH1 expression was extended to a dorsal side, indicating that SHL2 might be related to dorsoventral patterning. The above results of in situ hybrydization clearly indicate that OSH1 can be utilized as a marker for characterizing gene functions of embryo mutants.

• Journal of Plant Biotechnology
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• v.43 no.4
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• pp.457-465
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• 2016

Microsatellites are one of the most suitable markers for identification of variety, as they have the capability to discriminate between narrow genetic variations. The polymorphism level between 120 microsatellite primer pairs and 148 soybean varieties was investigated through the fluorescence based automatic detection system. A set of 16 primer pairs showed highly reproducible polymorphism in these varieties. A total of 204 alleles were detected using the 16 microsatellite markers. The number of alleles per locus ranged from 6 to 28, with an average of 12.75 alleles per locus. The average polymorphism information content (PIC) was 0.86, ranging from 0.75 to 0.95. The unweighted pair group method using the arithmetic averages (UPGMA) cluster analysis for 148 varieties were divided into five distinctive groups, reflecting the varietal types and pedigree information. All the varieties were perfectly discriminated by marker genotypes. These markers may be useful to complement a morphological assessment of candidate varieties in the DUS (distinctness, uniformity and stability) test, intervening of seed disputes relating to variety authentication, and testing of genetic purity in soybean varieties.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.4117-4123
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• 2016

Background: Methylation of promoter 2 of the SHP1 gene is epithelial cell specific, with reported potential as a lymph node metastatic marker. Objective: To demonstrate SHP1-P2 methylation-specific quantitative PCR effectiveness in detecting colorectal cancer (CRC) DNA in lymph nodes. Materials and Methods: SHP1-P2 methylation levels were measured in lymph nodes of CRC patients and compared with pathological findings and patient prognosis. Results: Lymph nodes of CRC metastatic patients without microscopically detectable cancer cells had higher SHP1-P2 methylation levels than lymph nodes of controls (p<0.001). In addition, a higher SHP1-P2 methylation level was associated with a shorter duration until adverse disease events, metastasis, recurrence and death (r2 = 0.236 and p value = 0.048). Studying two cohorts of 74 CRC patients without microscopic lymph node metastases showed that only the cohort containing samples with high SHP1-P2 methylation levels had a significant hazard ratio of 3.8 (95%CI = 1.02 to 14.2). Conclusions: SHP1-P2 methylation PCR can detect CRC DNA in lymph nodes even if cancer cells are not visible under a microscope, confirming applicability as a potential universal lymph node metastatic marker.