• Journal of Aquaculture
• /
• v.18 no.3
• /
• pp.207-214
• /
• 2005

We report on the diagnosis, pathology, and taxonomy of Perkinsus sp. infection in Manila clams (Ruditapes philippinarum) from Korean waters. Amplimers were designed from internal portions of the non-transcribed spacer (NTS) of P. atlanticus for molecular diagnosis of Perkinsus infection. PCR-based identification methods and an in situ hybridization assay were developed for detection of Perkinsus sp. in live tissues as well as in histological preparations. Hybridization signals were observed around the nucleus of trophozoites. Positive results from PCR and in situ hybridization indicated that Korean Perkinsus sp. is genetically identical with P. atlanticus reported in Europe, which is currently synonymous with P. olseni reported from Australia. Microscopic morphological features of different lift stages of Perkinsus sp. appeared very similar to those of P. atlanticus. Severely infected clams often exhibited white nodules on their mantles and gills as a consequence of inflammation. In lightly to moderately infected clams, Perkinsus sp. was mainly found in gill tissues, whereas the protozoan parasites were found in digestive tracts, gonadal tissues, and foot tissues of heavily infected clams. It is likely that the gills are the portal of the infection and that P. olseni spreads to other tissues as the infection advances. In conclusion, by considering the taxonomic priority of P. olseni, Korean Perkinsus sp. is accepted as P. olseni. P. olseni appears to be common on tidal flats on the western and southern Korean coasts and is considered to be a pathogen capable of causing mass mortality of clams.

• Journal of Sericultural and Entomological Science
• /
• v.50 no.2
• /
• pp.122-125
• /
• 2012

This study was aimed for a development of a useful gene promoter which has a transcript expressional specificity in the early embryonic period of the silkworm, Bombyx mori. To select a useful gene expressed in the early embryonic stage, we constructed and analyzed a PCR-base subtraction cDNA library. In subtractive hybridization analysis, we confirmed four clones as differently expressed genes(BmNanos-like, BmNanos-P, BmNanos-O, BmVasa mRNAs). Northern hybridization and real time PCR results reveled that the BmNanos-like gene promoter is suitable for the silkworm transgenic vector system. Further defined studies on molecular functions and biological roles of their promoters will give us well-fined information and its application.

• Molecular & Cellular Toxicology
• /
• v.4 no.3
• /
• pp.246-252
• /
• 2008

Tumor tissue is usually contaminated by normal tissue components, which reduces the sensitivity of analysis for exploring genetic alterations. Although microdissection has been adopted to minimize the contamination of tumor DNA with normal cell components, there is a concern over the amount of microdissected DNA not enough to be applied to array-CGH reaction. To amplify the extracted DNA, several whole genome amplification (WGA) methods have been developed, but objective comparison of the array-CGH outputs using different types of WGA methods is still scarce. In this study, we compared the performance of non-amplified microdissected DNA and DNA amplified in 2 WGA methods such as degenerative oligonucleotide primed (DOP)-PCR, and multiple strand displacement amplification (MDA) using Phi 29 DNA polymerase. Genomic DNA was also used to make a comparison. We applied those 4 DNAs to whole genome BAC array to compare the false positive detection rate (FPDR) and sensitivity in detecting copy number alterations under the same hybridization condition. As a result microdissected DNA method showed the lowest FPDR and the highest sensitivity. Among WGA methods, DOP-PCR amplified DNA showed better sensitivity but similar FPDR to MDA-amplified method. These results demonstrate the advantage and applicability of microdissection for array-CGH analysis, and provide useful information for choosing amplification methods to study copy number alterations, especially based on precancerous and microscopically invaded lesions.

• Parasites, Hosts and Diseases
• /
• v.37 no.4
• /
• pp.257-263
• /
• 1999

Identification of the genes responsible for the recovery of virulence in brain-passaged Acanthamoeba culbertsoni was attempted via mRNA differential display polymerase chain reaction (mRNA DD-PCR) analysis. In order to identify the regulatory changes in transcription of the virulence related genes by the brain passages, mRNA DD-PCR was performed which enabled the display of differentially transcribed mRNAs after the brain passages. Through mRNA DD-PCR analysis. 96 brain-passaged amoeba specific amplicons were observed and were screened to identify the amplicons that failed to amplify in the non-brain-passaged amoeba mRNAs. Out of the 96 brain-passaged amoeba specific amplicons, 12 turned out to be amplified only from the brain-passaged amoeba mRNAs by DNA slot blot hybridization. The clone, A289C, amplified with an arbitrary primer of UBC ＃289 and the oligo dT$_{11}$-C primer, revealed the highest homology (49.8％) to the amino acid sequences of UPD-galactose lipid transferase of Erwinia amylovora, which is known to act as an important virulence factor. The deduced amino acid sequences of an insert DNA in clone A289C were also revealed to be similar to cpsD, which is the essential gene for the expression of type III capsule in group B streptococcus. Upregulated expression of clone A289C was verified by RNA slot blot hybridization. Similar hydrophobicity values were also observed between A289C (at residues 47-66) and the AmsG gene of E. amylovora (at residues 286-305: transmembrane domains). This result suggested that the insert of clone A289C might play the same function as galactosyl transferase controlled by the AmsG gene in E. amylovora.a.

• Journal of Plant Biotechnology
• /
• v.43 no.3
• /
• pp.341-346
• /
• 2016

The objectives of this study were to 1) evaluate the efficiency of the protocol of Agrobacterium-mediated transformation of cucumber to introduce phytoene synthase-2a carotene desaturase (PAC genes); 2) demonstrate the integration of PAC genes into the genome of putative transgenic cucumber based on growth on selection medium, PCR and Southern analysis; 3) evaluate the expression of PAC genes in transgenic cucumber based on the analysis of RT-PCR and Northern blot hybridization. Out of 5,945 cotyledonary-node explants inoculated with Agrobacterium, 65 (1.1%) explants produced 238 shoots. Integration of PAC genes into the genome of the cucumber was demonstrated based on the analysis of gDNA-PCR, 21 out of the 238 plants regenerated; while 6 plants proved positive for Southern blot hybridization. Transgene expression was demonstrated based on analysis of RT-PCR, 6 plants proved positive out of the 6 plants analyzed; while 4 plants out of 6 proved positive during Northern blot hybridization. This study successfully demonstrated the production of transgenic cucumber, integration, and expression of the PAC gene in cucumber.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.6
• /
• pp.491-496
• /
• 2000

A RAG25 gene regulating flowering time was introduced into Codonopsis lanceolata through high efficiencies (ca. 90%) of plant regeneration. The leaf explants were immersed in YEP media containing Agrobacterium tumefaciens (pGA 1209) harboring RAG25 gene, and cocultivated for 3 days. After cocultivation, they were cultured in shoot inducing media (SIM), N2B2 (NAA 2 mg/L, BA 2 mg/L and kanamycin 20 mg/L) and N2B4 (NAA 2 mg/L, BA 4 mg/L and kanamycin 20 mg/L), and the putative transformants were regenerated. The introduction of nptII and RAG25 gene into Codonopsis lanceolata was confirmed by 0.7 kb and 0.6 kb bands from polymerase chain reaction and reconfirmed by Southern hybridization using PCR product of RAG25 gene.

• Plant Biotechnology Reports
• /
• v.3 no.4
• /
• pp.285-292
• /
• 2009

Zoysiagrass (Zoysia japonica) is one of the important turfgrass species. Extending green period of zoysiagrass via delaying leaf senescence will make this species have more potential in the turfgrass industry. In this study, we found that zoysiagrass seedlings treated with $GA_3$ could delay the leaf senescence induced by darkness. To study expression of genes responsive to staying green in zoysiagrass, suppression subtractive hybridization (SSH) was used to identify differentially expressed genes between non-$non-GA_3-treated$ and $GA_3-treated$ seedlings subjected to darkness. A total of 307 ESTs were generated, of which 226 ESTs clustered into 54 contigs and 81 were singlets. Differentially expressed genes selected by subtractions were classified into six categories according to their putative functions generated by BLAST analysis. Expression of five selected genes, Met, SAM, V-ATPase, Cry (Cryptochrome gene), and An (diphthine synthase gene) were examined by RT-PCR and Real-time PCR. Both RT-PCR and Real-time PCR results demonstrated that the differential expressions of these genes were attributable to delaying senescence by exogenously applied gibberellic acid. This is the first genome-wide study of senescence in a species of turfgrass.

• International Journal of Oral Biology
• /
• v.38 no.2
• /
• pp.43-49
• /
• 2013

The objective of this study was to develop PCR primers that are specific for Streptococcus sanguinis, Streptococcus parasanguinis, and Streptococcus gordonii. We designed the S. sanguinis-, S. parasanguinis-, and S. gordonii-specific primers, Ssa21-F3/Ssa21-R2, Spa17-F/Spa17-R, and Sgo41-F1/Sgo41-R1 respectively, based on the nucleotide sequences of the Ssa21, Spa17, and Sgo41 DNA probes that were screened using inverted dot blot hybridization (IDBH). The species-specificity of these primers was assessed against 43 strains of mitis group streptococci, including clinical strains of S. sanguinis, S. parasanguinis, and S. gordonii. The resulting PCR data revealed that species-specific amplicons had been obtained from all strains of the target species tested, and that none of these amplicons occurred in any other strains from other species. These results suggest that the Ssa21-F3/Ssa21-R2, Spa17-F/Spa17-R, and Sgo41-F1/Sgo41-R1 primers may be useful in detecting S. sanguinis, S. parasanguinis, and S. gordonii at the species level, respectively.

• Horticultural Science & Technology
• /
• v.32 no.1
• /
• pp.91-99
• /
• 2014

The objective of this study is to identify cold-tolerance genes in Brassica rapa. In order to acheive this goal, we analyzed a KBGP-24K oligo chip data [BrEMD (B. rapa EST and Microarray Database)] using B. rapa ssp. pekinensis inbred line 'Chiifu' under cold stress condition ($4^{\circ}C$). Among 23,929 unigenes of B. rapa, 417 genes (1.7%) were primarily identified as cold responsive genes that were expressed over 5-fold higher than those of wild type control, and then a gene which has unknown function and has full length sequence was selected. It was named BrCSR (B. rapa Cold Stress Resistance). BrCSR was transformed using expression vector pSL101 to confirm whether BrCSR can enhance cold tolerance in tobacco plants. $T_1$ transgenic tobacco plants expressing BrCSR were selected by PCR and Southern hybridization analyses, and the function of BrCSR was characterized by expression level analysis and phenotype observation under cold stress condition. The expression level of BrCSR in transgenic tobacco plants increased up to about two folds in quantitative real-time RT-PCR assay and this was very similar to Northern blot hybridization analysis. Analysis of phenotypic characteristics clearly elucidated that transgenic tobaccos expressing BrCSR were more cold tolerant than wild type control under $4^{\circ}C$ treatment. Based on these results, we conclude that the over-expression of BrCSR might be closely related to the enhancement of cold tolerance.

• Korean Journal of Veterinary Research
• /
• v.35 no.3
• /
• pp.531-536
• /
• 1995

Salmonella species are the most prevalent etiologic agents of food-borne acute gastroenteritis. Direct isolation of bacteria from the contaminated food, stool and animal tissues has been used for the diagnosis of salmonellosis routinely. However, isolation of bacteria is time consuming work and not so highly sensitive. In recent years, improved methods of polymerization chain reaction(PCR) and probe hybridization technique have led to the developement of diagnostic assays which employ to detect various human and animal pathogenic bacteria. In this study, we have performed the polymerization chain reaction to detect Salmonella pullorum from tissues and stool samples of chickens with two specific primers, ST5 and ST8C. The target DNA fragment of PhoE gene was successfully amplified from liver, spleen, pancreas, heart, lung, ovary, oviduct and feces samples. The amplified DNA fragments were hybridized with Salmonella typhymurium TA3000 PhoE probe by Southern hybridization. The PCR to amplify the PhoE gene was highly rapid and sensitive method to detect Salmonella pullorum from tissues and stool samples.