• Journal of Mushroom
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• v.2 no.3
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• pp.115-126
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• 2004

Somatic hybrids of inter-compatible and inter-incompatible strains were obtained by protoplast fusion. The fusion products between compatible strains, Pleurotus ostreatus and P. florida, formed heterokaryons, while fusants between incompatible strains such as P. cornucopiae + P. florida, P. ostreatus + Ganoderma applanatum, P. florida + Ganoderma lucidum, and P. ostreatus + Flammulina velutipes formed synkaryons that retained genes from both parents. The heterokaryons showed the same level of basidioma development. In contrast, the synkaryons showed unique characteristics including clamp connection formation at mitosis, either partner basidioma development, and abnormal segregation and recombination compared with inter-compatible strains. Synkaryons can be classified into homokaryoyic and heterokaryotic type. A comparison of somatic hybrids with compatible and incompatible strains was made using random amplified polymorphic DNA (RAPD) analysis. The heterokaryons between compatible species showed the same level of variability and contained both parental RAPD bands. In contrast, most of the synkaryons between incompatible species showed similarity to those of either parental bands and non-parental RAPD bands. Synkaryons can be classified into microgenome insertion type and macrogenome insertion type. A tetrapolar mating system was found among monospore isolates in somatic hybrids and wild type P. ostreatus. Homokaryons from each somatic hybrid combination were paired with tester homokaryons of the initial wild type of P. ostreatus. The changed mating types were identified in progenies. The pattern of mating type switching in somatic hybrids depends on compatibility of fusion partner. There are several factors related to the mechanism of clamp connection formation and fruiting body development of synkaryons. Of these,the major factor may be associated with self-fertility and mating type switching such as homokaryotic fruiting of wild type P. ostreatus. This review will discuss these aspects.

• Journal of Mushroom
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• v.15 no.3
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• pp.129-133
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• 2017

Oyster mushroom is a type of mushroom that is commonly cultivated and consumed in Korea. P. ostreatus 'Suhan' is a preferred cultivar for many mushroom farmers because it has a dark pileus and thick stipe. However, as it is very sensitive to environmental conditions, farmers consistently demand an alternative cultivar. To develop a new cultivar, the parental strains KMCC01680 ('Suhan') and KMCC00478 ('Gosol') were selected from various collected P. ostreatus strains by cultivating genetic resources. P. ostreatus 'Heuksol' was developed by the method of Mon-Mon crossing between monokaryotic strains derived from 'Suhan' and 'Gosol'. Thirty strains of 174 crossed strains were initially selected by cultivation experiments. After bulk cultivation tests, 'Heuksol' was selected. The nuclear DNA profile of 'Heuksol' was similar to those of the parental strains, 'Suhan' and 'Gosol', when RAPD (random amplified polymorphic DNA) primers and UPF (Universal PCR Fingerprinting) 2, 3, and 4 were used. The optimum temperature for mycelial growth was $30^{\circ}C$ for 'Heuksol', but medium-high temperatures were also appropriate, especially $13-20^{\circ}C$. The fruiting body production per bottle (1,100 mL) was approximately 140.8 g. When compared to the control strain 'Suhan', the thickness of the stipe of 'Heuksol' was greater than that of 'Suhan' (13.5 mm vs 9.4 mm). The pileus diameter of 'Heuksol' was similar to that of 'Suhan' and the pileus thickness of 'Heuksol' and 'Suhan' was 19.7 mm and 21.8 mm, respectively. 'Heuksol' had more a productive stipe number than 'Suhan' and the pileus of 'Heuksol' was dark gray, even at high temperatures. Therefore, it was suggested that this new cultivar, 'Heuksol', could provide an alternative to 'Suhan' and contribute to the profit of oyster mushroom farms.

• Journal of Korean Society of Forest Science
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• v.58 no.1
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• pp.1-7
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• 1982

Megagametophyte and embryo tissue of Pinus densiflora were subjected to study the inheritance of glutamate-oxalate transaminase(GOT) and leucine aminopeptidase(LAP), and linkage relationship among isozyme loci coding both enzymes by starch gel zone-electrophoresis. Four zones of activity were observed for GOT. No variation was found in the fastest migrating zone (GOT-A). Electrophoretic phenotypes of the other two zones (GOT-B and GOT-C) showed 1:1 segregation ration, suggesting that each zone is controlled by a single locus. Foru and three alleles were identified at both loci respectively. The isozyme pattern of the fourth zone(GOT-D), migrated cathodally, coincided precisely with that of GOT-C. Whether the two zones are controlled by the same locus or by two tightly linked loci remained unknown. In all three variant GOT zones, heterozygoes embryos produced triple band patterns, indicating that GOT isozyme in Pinus densiflora is a dimer. Two zones of activity stained for LAP were found. The segregation of the two zones (LAP-A and LAP-B) suggested that tow loci control each of both isozymes. Two and three alleles were identified at both loci. GOT-B and LAP-B were found to be tightly linked, showing an average recombination frequency of 12.5 percent. Slight deviation from independent assortment was observed between GOT-B and GOT-C, with recombination frequency of 41 percent.

• Journal of Animal Science and Technology
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• v.53 no.1
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• pp.29-34
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• 2011

Using the materials collected from nine farms in a three-way cross system to produce commercial pigs produced from F1 sows (Landrace $\times$ Large White) $\times$ Duroc, the power of individual discrimination and parentage of the 13 microsatellite (MS) marker set that has been suggested for individual/brand identification (traceability) was empirically tested. Initially, genotypes of the parental population ($F_1$ sows and Duroc), and commercial pigs were determined and the genotype frequency and polymorphic index were estimated using the Cervus 2.0 program. The probability of identity among genotypes of random individuals, that random half sibs and that of full sib individuals, based on the genotypes from 91 $F_1$ sows and Duroc were expected to be $4.94{\times}10^{-34}$, $8.16{\times}10^{-23}$ and $2.01{\times}10^{-08}$, respectively, using the API-CALC version 1.0 program. When commercial pigs were included, the estimates increased to $3.74{\times}10^{-35}$, $5.48{\times}10^{-25}$ and $2.96{\times}10^{-11}$, respectively. For the empirical verification of the estimated powers of individual discrimination and parentage, the parentage test was performed for 452 commercial pigs using PAPA version 2.0, and individuals with the same genotype were investigated using the Cervus version 2.0 program. Parents for all commercial pigs were successfully estimated and no identical individual was identified in the pedigree. Although the individual discriminating power was not fully verified because of the lack of individuals corresponding with the theoretical power, the 100% efficiency of parentage test was clearly confirmed. Therefore, we believe that the 13 MS marker set in conjunction with management record/information for the pig production kept in a farm/brand should be useful in the pork traceability in a brand unit.

• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.163-169
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• 2008

A total of 17 polymorphic microsatellite markers on chromosome 1 were used for allelic association tests with phenotypic traits in Korean native chicken. Chi-square tests were performed to compare the frequencies of individual alleles between the high and the low trait groups. The frequency of allele 123 of MCW0160 showed a significant difference between the high and the low groups in the trait of egg weight (EW). Three markers, namely ADL0234, UMA1.125 and ADL0101, were found to show significant differences in allelic distribution for the trait of the first lay day (FLD). UMA1.117, ADL0020, UMA 1.019, LMA1 and ADL0238 were found to show significant differences in allelic distribution for the trait of body weight (BW). ADL0101 and ADL0238 were found to show significant differences in allelic distribution for the trait of number of egg production(EP). In this study, we identified the QTL for economic traits at around 94 (MCW0160), 151 (ADL0234), 170 (UMA1.125), 225 (UMA1.117), 285 (ADL0020), 387 (UMA1.019), 418 (LMA1), 500 (ADL0101) and 520 (ADL0238) cM on chromosome 1 in Korean native chicken. The results provided a useful guideline for identification of positional candidate gene and marker-assisted selection for economic traits in Korean native chicken.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.772-781
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• 2013

The objective of this study was to develop simple sequence repeat (SSR) markers from expressed sequence tags (EST) of lettuce (Lactuca sativa) and identify 9 germplasms from 3 wild species of lettuce and 61 commercial cultivars using the developed EST-SSR markers. A total of 81,330 lettuce ESTs from NCBI databases were used to search for SSR and 4,229 SSR loci were identified. The highest proportion (59.12%, 2500) was represented by trinucleotide, followed by dinucleotide (29.70%, 1256) and hexanucleotide (6.62%, 280) among SSR repeat motifs. Totally 474 EST-SSR primers were developed from EST and a random set of 267 primers was used to assess the genetic diversity among 9 germplasms and 61 cultivars. Out of 267 primers, 47 EST-SSR markers showed polymorphism between 7 cultivars. Twenty-six EST-SSR markers among 47 EST-SSR markers showed high polymorphism, reproducibility, and band clearance. The relationship between 26 markers genotypes and 70 accessions was analyzed. Totally 127 polymorphic amplified fragments were obtained by 26 EST-SSR markers and two to nine SSR alleles were detected for each locus with an average of 4.88 alleles per locus. Average polymorphism information content was 0.542, ranging from 0.269 to 0.768. Genetic distance of clusters ranged from 0.05 to 0.94 between 70 accessions and dendrogram at a similarity of 0.34 gave 7 main clusters. Analysis of genetic diversity revealed by these 26 EST-SSR markers showed that the 9 germplasms and 61 commercial cultivars were discriminated by marker genotypes. These newly developed EST-SSR markers will be useful for cultivar identification and distinctness, uniformity and stability test of lettuce.

• Journal of Mushroom
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• v.9 no.2
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• pp.59-62
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• 2011

To develop a new cultivar of King oyster mushroom(Pleurotus eryngii), G09-21 as parental strain was selected by the method of Di-mon crossing between monokaryotic strains derived from ASI 2824(Keunneutari No.2) and dikaryotic strain ASI 2887(Aeryni 3). The Pe21-51($G09-21-10{\times}2844-11$) was shown the best cultural characteristics, selected to be a new cultivar and named as 'Song-A'. The 'Song-A' was formed incompatibility line distinctly in the confrontation growth of parental strains Keunneutari No.2, Aeryni 3 and ASI 2844. The optimum temperature for mycelial growth, fruiting body development and pH arrange were $25{\sim}30^{\circ}C$, $14{\sim}16^{\circ}C$ and pH5~8, respectively. Fruiting body production per bottle was about $94.7{\pm}29.5$ g which is almost 106% quantity compared to that of other cultuvar Keunneutari No.2. And also the stip is thick and long but the number of available stipe is few. Analysis of the genetic characteristics of the new cultivar 'Song-A' showed a different DNA profile as that of the control strains, Keunneutari No.2, Aeryni 3 and ASI 2844, when RAPD(Random Amplified Polymorphic DNA) primers URP4 and 7 were used. This new cultivar 'Song-A' of Pleurotus eryngii is characterized by a small number of primordia formation and the stip is thick and long. Therefore, we expect that this new strain will save of labor and cost by without culling work.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.342-347
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• 2004

A bacterial strain YC4963 with antifungal activity against Colletotrichum orbiculare, a causal organism of cucumber anthracnose was isolated from the rhizosphere soil of Siegesbeckia pubescens Makino in Korea. Based on physiological and biochemical characteristics and 16S ribosomal DNA sequence analysis, the bac­terial strain was identified as Pseudomonas aurantiaca. The bacteria also inhibited mycelial growth of several plant fungal pathogens such as Botrytis cinerea, Fusarium oxysporum and Rhizoctonia solani on PDA and 0.1 TSA media. The antifungal activity was found from the culture filtrate of this isolate and the active compound was quantitatively bound to XAD adsorption resin. The antibiotic compound was purified and identified as phenazine-l-carboxylic acid on the basis of combined spectral and chemical analyses data. This is the first report on the production of phenazine-l-carboxylic acid by Pseudomonas aurantiaca.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.828-835
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• 2010

Conventional methods for identification of apple cultivars are based on the evaluation of sets of morphological characteristics, however, closely related cultivars often cannot be distinguished by morphological traits. This study was conducted to develop DNA markers for discrimination of the apple cultivars bred in Korea. Thirty random primers generated eighty-three random amplified polymorphic DNA (RAPD) markers from thirty-one Korean bred and introduced apple cultivars. Fifty-two RAPD fragments were cloned and sequenced for conversion into sequence characterized amplified region (SCAR) markers. Among them only seventeen SCAR markers resulted in the amplification of single major bands the same size as the RAPD fragment cloned. Several combinations of six (AN11_433, AN08_566, A408_592, AK17_653, AO04_711, AO04_779 or AW15_368, AN11_433, A408_592, AK17_653, AO04_711, AO04_779, or AL1_427, AN11_433, AN08_566, A408_592, AK17_653, AO04_779) to seven (AL1_427, AN11_433, AN08_566, A408_592, AK17_653, AM16_708, AO04_779 or A330_424, AN11_433, AG14_502, AN08_566, A408_592, AK17_653, AO04_779 or A330_424, AN11_433, AK14_564, A408_592, AK17_653, AM16_708, AT14_789) SCAR markers provided enough polymorphism to identify sixteen Korean apple cultivars among thirty-one tested cultivars. Therefore, application of the seventeen SCAR markers was sufficient to identify the thirty-one tested apple cultivars. These markers could be utilized as a reliable tool for cultivar discrimination of Korean apples.

• Tuberculosis and Respiratory Diseases
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• v.55 no.6
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• pp.597-611
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• 2003

Background : Loss of the short arm of chromosome 16 is a frequent event in various cancers, which suggests the presence of tumor suppressor gene(s) there. To map precise tumor suppressor loci on the chromosome arm for further positional cloning efforts, we tested 23 primary small cell lung cancers. Method : The DNAs extracted from paraffin embedded tissue blocks with primary tumor and corresponding control tissue were investigated. Twenty polymorphic microsatellite markers located in the short arm of chromosome 16 were used in the microsatellite analysis. Results : We found that six (26.1%) of 23 tumors exhibited LOH in at least one of tested microsatellite markers. Two (8.7%) of 6 tumors exhibiting LOH lost a larger area in chromosome 16p. LOH was observed in five common deleted regions at 16p. Among those areas, LOH between D16S668 and D16S749 was most frequent (21.1%). LOH was also observed at four other regions, between D16S3024 and D16S748, D16S405, D16S420, and D16S753. Six of 23 tumors exhibited shifted bands in at least one of the tested microsatellite markers. Shifted bands occurred in 3.3% (15 of 460) of the loci tested. Conclusion : Our data demonstrated that at least five tumor suppressor loci might exist in the short arm of chromosome 16 and that they may play an important role in small cell lung cancer tumorigenesis.