• Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.286-292
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• 2009

We have constructed a cDNA library using brain samples of olive flounder Paralichthys olivaceus. Here, we described the study on gene identification by screening 356 clones from the brain cDNA library of olive flounder. Here, we screened 356 clones from the library to identify genes. Of these, 176 (49.5%) were identified as orthologs of known genes from olive flounder and other organisms. Among the 176 EST clones, 33 (18.7%) represented 11 unique genes that are identical to expressed sequence tags (ESTs) reported for olive flounder, and 120 (68.2%) represented 102 unique genes known from other organisms. The percentage of unknown genes (50.5%) is higher than in other olive flounder cDNA libraries (Lee et al., 2003, 2006, 2007), reflecting the high complexity of brain tissue. Further studies of expression characterization and developmental behavior related to these genes should provide useful insight into the physiological functions of the brain in olive flounder.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.122-122
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• 2003

Expressed sequence tags (EST) are help to quickly identify functions of expressed genes and to understand the complexity of gene expression. In order to analyze gene expression of the leaf development in Panax ginseng, which is one of the most important medicinal plant, expressed sequence tags (EST) analysis was carried out. We constructed a cDNA library using the immature leaf of Chunpoong. Partial sequences were obtained from 3,170 clones. The ESTs could be clustered into 1,624 (56.1%) non-redundant groups. Similarity search of the non-redundant ESTs against public non-redundant databases of both protein and DNA indicated that 1,137 groups show similarity to genes of known function. These ESTs clones were divided into sixteen categories depending upon gene function. Most abundant transcripts in immature ginseng leaf were photosynthesis related protein, such as chlorophyll a/b binding protein LHCII type I (128), chlorophyll a/b binding protein (53), ribulose-1,5-bisphosphate carboxylase (41), and photosystem I psaH (26). The EST data from immature leaf generated in this study is useful in dissecting gene expression in leaf organ of ginseng.

• 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.

• Journal of Microbiology
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• v.45 no.6
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• pp.541-546
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• 2007

Red algae are distributed globally, and the group contains several commercially important species. Griffithsia okiensis is one of the most extensively studied red algal species. In this study, we conducted expressed sequence tag (ESTs) analysis and synonymous codon usage analysis using cultured G. okiensis samples. A total of 1,104 cDNA clones were sequenced using a cDNA library made from samples collected from Dolsan Island, on the southern coast of Korea. The clustering analysis of these sequences allowed for the identification of 1,048 unigene clusters consisting of 36 consensus and 1,012 singleton sequences. BLASTX searches generated 532 significant hits (E-value <$10^{-4}$) and via further Gene Ontology analysis, we constructed a functional classification of 434 unigenes. Our codon usage analysis showed that unigene clusters with more than three ESTs had higher GC contents (76.5%) at the third position of the codons than the singletons. Also, the majority of the optimal codons of G. okiensis and Chondrus crispus belonging to Bangiophycidae were G-ending, whereas those of Porphyra yezoensis belonging to Florideophycidae were G-ending. An orthologous gene search for the P. yezoensis EST database resulted in the identification of 39 unigenes commonly expressed in two rhodophytes, which have putative functions for structural proteins, protein degradation, signal transduction, stress response, and physiological processes. Although experiments have been conducted on a limited scale, this study provides a material basis for the development of microarrays useful for gene expression studies, as well as useful information for the comparative genomic analysis of red algae.

• Journal of Aquaculture
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• v.20 no.4
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• pp.248-254
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• 2007

Representative cDNA libraries were constructed from various tissue sources of Hemibarbus mylodon, an endangered freshwater fish species in Korea, for the mining of expressed sequence tags (ESTs). Randomized and non-normalized EST analysis was performed with 7 unidirectional cDNA libraries generated from brain, intestine, kidney, liver, muscle, ovary or testis. Of 3,383 ESTs in total, the number of singleton was 2,029, and 333 contigs containing 1,354 ESTs were assembled (percent of unigene = 70.0%). Abundantly expressed gene transcripts and broad clustering of putative gene function were tissue-specific in general, and the redundancy was also variable among those libraries. Over half of H. mylodon ESTs were matched with orthologues from other teleosts among which zebrafish gene sequences were the most frequent in those matches. This initial setting of EST libraries achieved in the present study would be a fundamental basis for the banking of gene resources from this endangered fish species.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.167-171
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• 2004

We constructed an oligo-d(T) primed directional cDNA library from the Bombyx mandarina whole larvae. In an effort to isolate genes expressed in the B. mandarina, 227 expressed sequence tags (ESTs) were generated by single-pass sequencing from the cDNA library. Sequence analysis showed that 107 clones (47.1%) were classified into known genes and 120 clones (52.9%) were novel transcripts, which are unknown for their function. Of the 107 known genes, the most abundant gene was found to be actin and followed by serine protease in the expression profile. Among these clones, a serine protease homolog (BmSP) which is a class of proteolytic enzymes isolated. Full-length sequence of the BmSP cDNA clone was 922 bp in length and has an open reading frame of 276 amino acids. The conserved histidine, aspatic acid and serine residues forming the catalytic center as well as cysteine residues contributing to three disulphide bonds also were found in Bmsp gene. mRNA expression analysis revealed a high and specific expression of the gene only in midgut tissue, suggesting that BmSP gene is closely associated with the expression of digestive enzyme.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.238.2-238
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• 1998

No Abstract, See Full Text

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.316-316
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• 2005

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2004.10a
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• pp.69-69
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• 2004

• Proceedings of the Botanical Society of Korea Conference
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• 2000.04a
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• pp.20-20
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• 2000