• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.181-182
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• 2002

Expressed sequence tags (ESTs) are generated by single-pass DNA sequencing of clones obtained from cDNA libraries and are powerful tool in the genetic characterization of organisms, owing in large part to the speed and affordability of generating these sequences. Comparison of sequences obtained with those available in public sequence databases allows putative identification of many genes. (omitted)

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.124-124
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• 2003

In order to study gene expression in a reproductive organ, we constructed a cDNA library of immature flower buds in Korean ginseng and generated expressed sequence tags (ESTs) of 3,360 clones randomly selected. The ESTs could be clustered into 1,844 non-redundant groups. Similarity search of the non-redundant ESTs against public non-redundant databases of both protein and DNA indicated that 1,254 groups show similarity to genes of known function. These ESTs clones were divided into sixteen categories depending upon gene function. The most abundant transcripts were unknown protein (72), chlorophyll a/b-binding protein (48), and stylar glycoprotein. There are no useful informations of gene expression during the development of flower bud in Korean ginseng. These results could help to understand the development of flower bud in Korean ginseng.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.67-68
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• 2003

한국 재래 닭의 유전적 특성 규명 및 기능 유전체 연구의 기초재료를 확보하고자 대량 EST 염기서열 결정 및 생물정보학 분석을 실시하였다. 대량 EST 염기서열 분석을 위한 첫 번째 단계로 재래 닭의 뇌, 비장, 정소, 배아 생식기를 이용하여 cDNA library를 구축하였다. 각각의 library로부터 총 15,121개의 클론을 선정하여 염기서열을 결정하였다. 생물정보학 분석결과 15,121개의 염기서열은 총 10,353개의 contig로 정리되었다. 이들 염기서열을 기존 데이터베이스를 대상으로 tBlastX(http://www.ncbi.nlm.nih.gov/BLAST) 분석을 실시한 결과, 염기서열 중 56 ％가 기존 데이터베이스에 존재하는 유전자와의 상동성을 보였다. 상동성을 보이는 유전자들은 유전자의 구조 및 기능 분석에 이용될 것이고, 상동성을 보이지 않는 유전자들은 microarray와 같은 대량 유전자 발현분석 시스템을 이용하여 선별한 후 기능분석이 실시될 것이다.

• Journal of Sericultural and Entomological Science
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• v.38 no.1
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• pp.13-18
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• 1996

To secure the genetic resources of silkworm, Bomyx mori, the cDNA library was constructed with mRNA isolated from fifth instar larvae. Titer of the cDNA library was about 1.3 X 106 plaques in total. We presumed that the titer covered all transcripts existed in Bombyx mori. Meanwhile, it is knowen that partial cDNA sequences, Expressed Sequence Tags(ESTs), have a good value for the discovery of novel genes and the elucidation of their structures. For this purpose, partial cDNA sequencing was carried out from randomly selected cDNA clones in the library. Partial cDNA sequences of 37 clones were determined and an average of 212 nucleotides of sequence can be read from the clone. The ESTs were searched in GenBAnk database and fifteen ESTs showed significant similarities to enlisted sequences. They included the genes of storage protein, heat shock protein, actin, catalase and so forth. We presumed that the 22 unmatched ESTs were novel genes.

• Journal of Life Science
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• v.24 no.11
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• pp.1187-1192
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• 2014

Pepper, consumed as a typical spice food around world, is mainly cultivated in warm countries, including Korea, China, and Mexico. Phytophthora capsici is a pathogen on several economically important crops, including pepper. The oomycete attacks the roots, stems, leaves, and fruit of the host plants. To understand the molecular mechanisms underlying development of the disease, the genes expressed during pepper-P. capsici interaction were explored by analyzing expressed sequence tags (ESTs). A cDNA library was constructed from total RNA extracted from pepper leaves challenged with P. capsici for three days, resulting in an early stage of symptom development for comparable interaction. A comprehensive analysis of single-pass sequencing of 5,760 randomly selected cDNA clones extracted 5,148 high-quality entries for contig assembly, which generated 2,990 unigenes. A homology search of the unigenes with BLASTX resulted in 2,409 matches, of which 606 showed classified functional catalogs.

• BMB Reports
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• v.39 no.2
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• pp.183-188
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• 2006

Using the Phred/Phrap/Polyphred/Consed pipeline established in the National Livestock Research Institute of Korea, we predicted candidate coding single nucleotide polymorphisms (cSNPs) from 7,600 expressed sequence tags (ESTs) derived from three cDNA libraries (liver, M. longissimus dorsi, and intermuscular fat) of Hanwoo (Korean native cattle) steers. From the 7,600 ESTs, 829 contigs comprising more than two EST reads were assembled using the Phrap assembler. Based on the contig analysis, 201 candidate cSNPs were identified in 129 contigs, in which transitions (69%) outnumbered transversions (31%). To verify whether the predicted cSNPs are real, 17 SNPs involved in lipid and energy metabolism were selected from the ESTs. Twelve of these were confirmed to be real while five were identified as artifacts, possibly due to expressed sequence tag sequence error. Further analysis of the 12 verified cSNPs was performed using the program BLASTX. Five were identified as nonsynonymous cSNPs, five were synonymous cSNPs, and two SNPs were located in 3'-UTRs. Our data indicated that a relatively high SNP prediction rate (71%) from a large EST database could produce abundant cSNPs rapidly, which can be used as valuable genetic markers in cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.170-178
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• 2005

An in silico approach was developed to survey the genes expressed in four internal organs of pig: liver, kidney, spleen and small intestine. The major procedures of the approach included: (1) BLAST searching against GenBank "est_others" database using human cDNA sequences as queries to screen the porcine orthologous expressed sequence tags (ESTs), (2) classifying the porcine ESTs records by resources according to certain criteria and (3) analyzing data for ESTs specifically expressed in each organ. In order to do so, four Java programs were developed. Based on the ESTs available in the GenBank database, it was found that there were at least 2,100 genes expressed in these four organs, including 128 in the liver, 81 in the kidney, 780 in the spleen, and 1,423 in the small intestine respectively (a few genes co-expressed in these tissues). Gene expression patterns, such as co-expressed genes, preferentially expressed genes and basic active genes were also compared and characterized among these organs. This study provides a comprehensive model on how to use the bioinformatics approach and Genbank databases to facilitate the discovery of new genes in livestock species.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.3
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• pp.168-173
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• 2007

of expressed sequence tags (ESTs) is an efficient approach for gene discovery, expression profiling, and development of resources useful for functional genomics. To analyze the transcriptome of olive flounder, Paralichthys olivaceus, we have conducted EST analysis using cDNA libraries made from muscle of P. olivaceus. Redundant ESTs were assembled into overlapping contigs by using the assembly program ICAtools software. We found that the 221 ESTs were composed of 21 clusters and 35 singletons, suggesting that the overall redundancy of the library was 74.7%. Of the 221 clones, 218 clones (98.6%) were identified as known genes by BLAST searches and 3 clones (1.4%) did not match to any previously described genes. Based on major functions of their encoded proteins, the identified clones were classified into 13 broad categories. Sequence analysis of the ESTs revealed the presence of microsatellite-containing genes which may be valuable for further gene mapping studies. This study contributes to the identification of many EST clones that could be useful for genetics and developmental biology of olive flounder.

• Journal of fish pathology
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• v.21 no.2
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• pp.129-137
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• 2008

We constructed a black rockfish (Sebastes schlegeli) leukocyte cDNA library and a total of 386 expressed sequence tag (EST) clones were generated. Gene annotation procedures and homology searches of the sequenced ESTs were locally done by BLASTX for amino acid similarity comparisons. Of the 386 EST clones, 199 different ESTs showed significant homology to previously described genes while 97 ESTs were unidentified, hypothetical, or unnamed proteins. Encoding 38 different sequences were identified as putative bio-defense genes or genes associated with immune response.

• The Korean Journal of Malacology
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• v.30 no.2
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• pp.155-163
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• 2014

Serpins are a group of proteins involved in the regulation of serine and other type of proteases, and have been identified in many kinds of organisms from invertebrates to vertebrates. Serpins are known to regulate the proteolytic cascades of the innate immune pathways in addition to their roles in blood coagulation, angiogenesis, fibrinolysis, inflammation and tumor suppression. In this study, we have isolated two partial serpin gene fragments from expressed sequence tags (ESTs) of Nesiohelix samarangae. Dotplot analysis indicates that they are of two different types, Ns-serpin type 1 and Ns-serpin type 2. Ns-serpin type 1 has 819 bp coding region (272 amino acids), whereas Ns-serpin type 2 has 555 bp coding region (185 amino acids). Molecular phylogenetic analysis shows that the identified serpins have high similarities to their counterparts in the California see slug, Aplysia californica. Yet, the precise biological and immunological roles of these Ns-serpins remain to be further investigated using RNA interference and other molecular techniques.