• The Korean Journal of Malacology
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• v.29 no.3
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• pp.181-187
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• 2013

In order to investigate environmental stress inducible genes in abalone, we analyzed differentially expressed transcripts from a Pacific abalone, Haliotis discus hannai, after exposure to heat-, cold- or hyposalinity-shock by suppression subtractive hybridization (SSH) method. 1,074 unique sequences from SSH libraries were composed to 115 clusters and 986 singletons, the overall redundancy of the library was 16.3%. From the BLAST search, of the 1,316 ESTs, 998 ESTs (75.8%) were identified as known genes, but 318 clones (24.2%) did not match to any previously described genes. From the comparison results of ESTs pattern of three SSH cDNA libraries, the most abundant EST was different in each SSH library: small heat shock protein p26 (sHSP26) in heat-shock, trypsinogen 2 in cold-shock, and actin in hyposalinity SSH cDNA library. Based on sequence similarities, several response-to-stress genes such as heat shock proteins (HSPs) were identified commonly from the abalone SSH libraries. HSP70 gene was induced by environmental stress regardless of temperature-shock or salinity-stress, while the increase of sHSP26 mRNA expression was not detected in cold-shock but in heat-shock condition. These results suggest that the suppression subtractive hybridization method is an efficient way to isolate differentially expressed gene from the invertebrate environmental stress-response transcriptome.

• Molecular & Cellular Toxicology
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• v.2 no.1
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• pp.60-66
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• 2006

Methylmercury (MeHg), one of the heavy metal compounds, can cause severe damage to the central nervous system in humans. Many reports have shown that MeHg is poisonous to human body through contaminated foods and has released into the environment. Despite many studies on the pathogenesis of MeHg-induced central neuropathy, no useful mechanism of toxicity has been established so far. This study, using of suppression subtractive hybridization (SSH) method, was peformed to identify differentially expressed genes by MeHg in SH-SY5Y human neuroblastoma cell line. We prepared to total RNA from SH-SY5Y cells treated with solvent (DMSO) and $6.25\;{\mu}M\;(IC_{50})$ MeHg and performed forward and reverse SSH. Differentially expressed cDNA clones were screened by dot blot, sequenced and confirmed that individual clones indeed represent differentially expressed genes with real time RT-PCR. These sequences were identified by BLAST homology search to known genes or expressed sequence tags (ESTs). Analysis of these sequences may provide an insight into the biological effects of MeHg in the pathogenesis of neurodegenerative disease and a possibility to develop more efficient and exact monitoring system of heavy metals as ubiquitous environmental pollutants.

• BMB Reports
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• v.40 no.6
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• pp.986-1001
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• 2007

Cold acclimation improves freezing tolerance in plants. In higher plants, many advances have been made toward identifying the signaling and regulatory pathways that direct the low-temperature stress response; however, similar insights have not yet been gained for simple nonvascular plants, such as bryophytes. To elucidate the pathways that regulate cold acclimation in bryophytes, we used two PCR-based differential screening techniques, cDNA amplified fragment length polymorphism (cDNA-AFLP) and suppression subtractive hybridization (SSH), to isolate 510 ESTs that are differentially expressed during cold acclimation in Physcomitrella patens. We used realtime RT-PCR to further analyze expression of 29 of these transcripts during cold acclimation. Our results show that cold acclimation in the bryophyte Physcomitrella patens is not only largely similar to higher plants but also displays distinct differences, suggests significant alteration during the evolution of land plants.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.440-446
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• 2006

To investigate flowering related genes in winter-type oilseed rape (Brassica napus L. cv. Tammi), differentially expressed genes were isolated from leaves of the plant after low temperature treatment which is requirements for floral induction. As a result of suppression subtractive hybridization (SSH), 288 clones were randomly selected from SSH library. Using reverse Northern blot analysis, 150 of 288 clones were identified to be differentially expressed. Out of these 150 clones, 45 clones showed very high identities with the known genes. Four clones showed very high identities over 90% with metallothionein-like gene that is related to flowering-induced genes. Of these 4 clones, the cDNA clone, rfs-13, revealed high identity with meotallothionein-like protein in Arabidopsis thaliana (98%) and Brassica compestris (89%). Furthermore, gene expressed in immature flower stages was confirmed by Northern blot analysis.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.43-50
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• 2005

Purpose : A number of genes and their products are Induced early or late following exposure of cells to ionizing radiation. These radiation-Induced genes have various effects on irradiated cells and tissues. Suppression subtractive hybridization (SSH) based on PCR was used to Identify the differentially expressed genes by radiation in cervix carcinoma cells. Materials and Methods : Total RNA and poly $(A)^+$ mRNA were Isolated from Irradiated and non-irradiated HeLa cells. Forward- and reverse-subtracted cDNA libraries were constructed using SSH. Eighty-eight clones of each were used to randomly select differentially expressed genes using reverse Northern blotting (dot blot analysis). Northern blotting was used to verify the screened genes. Results : Of the 17t clones, 10 genes in the forward-subtracted library and 9 genes In the reverse-subtracted library were identified as differentially expressed radiation-induced genes by PCR-select differential screening. Three clones from the forward-subtracted library were confirmed by Northern blotting, and showed increased expression in a dose-dependent manner, including a telomerase catalytic subunit and sodium channel-like protein gene, and an ESTs (expressed sequence tags) gene. Conclusion : We Identified differentially expressed radiation-induced genes with low-abundance genes with SSH, but further characterization of theses genes are necessary to clarify the biological functions of them.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.1
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• pp.17-24
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• 2010

In the antral follicle phase, several layers of cumulus cells surround the oocyte and play an important support and regulation role in oocyte development and maturation via intercellular communications and interactions between oocytes and cumulus cells. However, information on stage specific gene expression in swine during the phase is not well understood. To investigate the function of cumulus cells during in vitro maturation of porcine oocytes and gene expression, suppression subtractive hybridization (SSH) was performed to screen genes that were differentially expressed between cumulus-oocyte complexes (COCs) and naked oocytes (NOs). Utilizing mRNAs from in vitro maturation oocytes, a SSH cDNA library from COCs as the tester and NOs as the driver was constructed. The SSH cDNA library was then screened using dot blot analysis. Results showed that a total of 70 clones randomly selected from the library were differentially expressed. Among these, 41 exhibited high homology to known genes and 11 were novel expressed sequences tags (ESTs). Four differentially expressed genes, including bfgf, sprouty 2, egr and btc, were further studied by real time quantitative PCR; results confirmed an increased expression of respective mRNA in COCs compared with NOs, which suggests that these factors may play an important role in oocyte development and maturation.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.898-903
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• 2009

Pullorum disease affecting poultry is caused by Salmonella enterica serovar Pullorum and results in severe economic loss every year, especially in countries with a developing poultry industry. The pathogenesis of S. Pullorum is not yet well defined, as the specific virulence factors still need to be identified. Thus, to isolate specific DNA fragments belonging to S. Pullorum, this study used suppression subtractive hybridization. As such, the genome of the S. Pullorum C79-13 strain was subtracted from the genome of Salmonella enterica serovar Gallinarum 9 and Salmonella enterica serovar Enteritidis CMCC(B) 50041, respectively, resulting in the identification of 20 subtracted fragments. A sequence homology analysis then revealed three types of fragment: phage sequences, plasmid sequences, and sequences with an unknown function. As a result, several important virulence-related genes encoding the IpaJ protein, colicin Y, tailspike protein, excisionase, and Rhs protein were identified that may play a role in the pathogenesis of S. Pullorum.

• Journal of fish pathology
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• v.19 no.3
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• pp.189-195
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• 2006

A subtracted cDNA library of a marine scuticociliate, Philasterides dicentrarchii, in response to 17β-estradiol exposure was constructed using suppression subtractive hybridization (SSH). As a result of SSH, 275 clones were isolated, and among them, only glutathione peroxidase (GPX) gene was isolated as an antioxidative enzyme responding to 17β-estradiol. The semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) analysis revealed that the transcription of GPX gene of P. dicentrarchii was clearly increased by exposure to 17β-estradiol. The GPX transcription was also clearly increased by exposure to xenoestrogens such as bisphenol A (BPA) and genistein.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.234-242
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• 2008

To identify low temperature-induced genes of wheat chromosome substitution line 5D, suppression subtractive hybridization (SSH) was performed with mRNAs from leaf samples that treated with low temperature ($4^{\circ}C$). A cDNA library was constructed using mRNA isolated from wheat chromosome substitution line 5D leaves treated with low temperature ($4^{\circ}C$). The nucleotide and deduced amino acid sequences of the putative gene products were compared. wfr-9 and wfr-32 showed identity over 90% related to vernalization gene. Other two genes, wfr-77 and wfr-83 which is related to freezing-resistant gene have also identity over 90%. This result suggest that those genes may be transcribed into antifreeze proteins which are accumulated within leaf apoplasts, when wheat chromosome substitution line 5D is acclimated during low temperature treatment.

• Korean Journal of Breeding Science
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• v.41 no.2
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• pp.73-83
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• 2009

To investigate genes related to vernalization and cold- resistance in barley (Hordeum vulgare L. cv. Nagaoka), differentially expressed genes were identified from cold-resistant barley leaves with suppression subtractive hybridization (SSH) and Northern blot analyses. The nucleotide and the deduced amino acid sequences of the putative gene products were compared. The bvrn-7 showed high homology(84%) with gene related to vernalization, and the bvrn-3, bvrn-12, bvrn-28, bvrn-29 and bvrn-36 related to cold-resistant genes had high identity of 88~98% with low temperature-induced genes. The results indicate that the 6 genes were closely related to vernalization and cold-resistance during low temperature treatment.