• 한국어류학회지
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• 제18권4호
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• pp.283-292
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• 2006

넙치 (Paralichthys olivaceus) 신장에서 추출한 mRNA로부터 cDNA library를 제작하고 이를 이용하여 EST (Expressed sequence tag) 분석을 하였다. 넙치의 신장 cDNA library에서 무작위로 선별한 390개의 EST를 조사한 결과, 250개의 EST는 이미 밝혀진 유전자와 유사성이 있는 것으로 나타났으며, 140개의 EST는 새로운 유전자로 밝혀졌다. 유전자의 기능이 밝혀진 250개의 EST 중 14 (5.6%)개의 EST는 이미 알려진 넙치 EST와 상동성이 있는 유전자로 확인되었고, 198 (79.2%)개의 EST는 다른 생물에서 알려진 유전자와 상동성이 있는 것으로 나타났다. 그러나 38 (15.2%)개의 EST는 전혀 기능이 알려지지 않은 새로운 유전자로 밝혀졌다. EST 분석은 새로운 유전자 뿐만 아니라 기능적으로 중요한 유전자를 탐색하는데도 아주 강력한 연구 방법이다. 이에 따라 본 연구에서는 넙치 신장 EST 분석을 통해 C-, L-type lectin과 MHC class II-invariant chain like proteins (li) 같은 면역기능과 관련이 있는 여러 개의 유전자를 확인하였고, 이들 유전자들은 질병감염 후 유전자 발현에서 나타나는 차이를 분석하는데 이용되는 cDNA microarray 연구에 유용하게 사용될 것으로 보인다.

• 한국어병학회지
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• 제23권3호
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• pp.429-440
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• 2010

We constructed a rock bream (Oplegnathus fasciatus) gill cDNA library and a total of 1450 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 1450 EST clones, 1022 EST clones showed significant homology to previously described genes while 428 ESTs were unidentified, and 259 clones were hypothetical, or unnamed proteins. Encoding 313 different sequences were identified as putative bio-defense genes or genes associated with immune response.

• 한국어류학회지
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• 제19권4호
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• pp.257-265
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• 2007

본 연구에서는 넙치(Paralichthys olivaceus) 정소에 대한 cDNA library를 제작하여 총 248개의 EST (Expressed sequence tag)를 분석을 하였다. 넙치 정소의 유전자 발현 패턴을 조사하기 위하여 염기서열의 유사성 분석을 한 결과 248개의 EST 중 156개의 EST는 이미 밝혀진 유전자와 유사성이 있는 것으로 나타났으며, 92개의 EST는 새로운 유전자로 밝혀졌다. 유전자의 기능이 밝혀진 250개의 EST 중 6개(3.8%)의 EST는 이미 알려진 넙치 EST와 상동성이 있는 유전자로 확인되었고, 100개(64.1%)의 EST는 다른 생물에서 알려진 유전자와 상동성이 있는 것으로 나타났다. 그러나 50개(32.1%)의 EST는 전혀 기능이 알려지지 않은 새로운 유전자로 밝혀졌다. 이상의 결과에서 넙치 정소에서 발현되는 유전자는 다른 조직에 비해 일부 유전자의 상대적인 발현정도가 많지 않고, 대부분의 유전자가 골고루 발현함으로써 다양한 유전자의 발현패턴이 확인되었다. 따라서 넙치 정소에 대한 cDNA library는 특이하고 새로운 발현 유전자의 탐색에 좋은 재료로 사용될 것으로 추측된다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 춘계 학술발표대회
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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 Microbiology and Biotechnology
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• 제22권7호
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• pp.902-906
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• 2012

Expressed sequence tags (ESTs) from the Antarctic green algae Pyramimonas gelidicola were analyzed to obtain molecular information on cold acclimation of psychrophilic microorganisms. A total of 2,112 EST clones were sequenced, generating 222 contigs and 219 singletons, and 200 contigs and 391 singletons from control ($4^{\circ}C$) and cold-shock conditions ($-2^{\circ}C$), respectively. The complete EST sequences were deposited to the DDBJ EST database (http://www.ddbj.nig.ac.jp/index-e.html) and the nucleotide sequences reported in this study are available in the DDBJ/EMBL/GenBank. These EST databases of Antarctic green algae can be used in a wide range of studies on psychrophilic genes expressed by polar microorganisms.

• 한국양식학회지
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• 제16권1호
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• pp.8-14
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• 2003

To generate expressed sequence tags for genomics research involving genetic linkage analysis, to examine gene expression profiles in muscles of channel catfish in a non-normalized muscle cDNA library, to compare gene expression in young and mature channel catfish muscles using the EST reagents and gene filters to demonstrate the feasibility of functional genomics research in small laboratories. 102 randomly picked cDNA clones were analyzed from the catfish muscle cDNA library. Of the sequences generated, 90.2% of ESTs was identified as known genes by identity comparisons. These 92 clones of known gene products represent transcriptional products of 24 genes. The 10 clones of unknown gene products represent 8 genes. The major transcripts (70.1% of the analyzed ESTs) in the catfish muscle are from many major genes involved in muscle contraction, relaxation, energy metabolism and calcium binding such as alpha actin, creatine kinase, parvalbumin, myosin, troponins, and tropomyosins. Gene expression of the unique ESTs was comparatively studied in the young and adult catfish muscles. Significant differences were observed for aldolase, myostatin, myosin light chain, parvalbumin, and an unknown gene. While myosin light chain and an unknown gene (CM 192) are down-regulated in the mature fish muscle, the aldolase, myostatin, and parvalbumin are significantly up-regulated in the mature fish muscle. Although the physiological significance of the changes in expression levels needs to be further addressed, this research demonstrates the feasibility and power of functional genomics in channel catfish. Channel catfish muscle gene expression profiles provide a valuable molecular muscle physiology blueprint for functional comparative genomics.

• 한국어병학회지
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• 제22권3호
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• pp.383-389
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• 2009

Analysis of expressed sequence tags (ESTs) is an efficient approach for gene discovery, expression profiling, and development of resources useful for functional genomics studies. As part of studies on the immune system of olive flounder, a total of 251 EST sequences from gill cDNA library were generated to identify and characterize important genes in the immune machanisms of olive flounder. Of the 251 clones, 126 clones (50.2%) were identified as orthologues of known genes from olive flounder and other organisms. Among the 126 EST clones, 16 clones (12.7%) were representing 9 unique genes identified as homologous to the previously reported olive flounder ESTs, 100 clones (79.4%) representing 103unique genes were identified as orthologs of known genes from other organisms. We also identified several kinds of immune associated proteins, indicating EST as a powerful method for identifying immune related genes of fish as well as identifying novel genes. Further studies using cDNA microarrays are needed to identify the differentially expressed transcripts after disease infection.

• 생명과학회지
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• 제10권2호
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• pp.188-195
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• 2000

In order to understand molecular events during silk synthesis and provide genetic resources for molecular breeding, we had analyzed the cDNA library constructed from the posterior silkgland of Antheraea yamamai and partially sequenced 276 randomly selected genes from the cDNA library. Database comparisons of the expressed sequence tags (ESTs) revealed that 26 non-redundant clones showed a high similarity with previously identified genes. Among them, 17 clones exhibited a homology with previously identified insect genes and 9 clones were identical to genes that were previously identified from other organisms. A functional categorization showed that silk synthesis-defense- or stress-related genes, as well as genes involved in the metabolic pathways and in the transcriptional or translational apparatus are represented. In this report, the clone (AY479) which had high similarity with fibroin from A. pernyi was particularly analyzed in detail. The AY479 clone was carboxyl terminal region of fibroin. The 472 bp cDNA has 123 amino acids that shared 85% homology with the fibroin from A. pernyi and its deduced peptide had unique feature, that is, sites of alanine rich residues.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 춘계 학술발표대회
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• pp.123-123
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• 2003

In order to study gene expression transcribted during the embryo development, we constructed a cDNA library of embryogenic callus induced from cotylendon of Korean ginseng and generated expressed sequence tags (ESTs) of 3,359 clones randomly selected. The ESTs could be clustered into 1,910 (59.1%) non-redundant groups. Similarity search of the non-redundant ESTs against public non-redundant databases of both protein and DNA indicated that 2,217 groups show similarity to genes of known function. These ESTs clones were divided into eighteen categories depending upon gene function. Most abundant transcripts were ribosomal protein small subunit 28kDa(40), tumor-related protein(35), metallothionein (31), small heat-shock protein class 18.6K(24), and cyclophilin(20). There are no useful informations of gene expression during the embryo development in Korean ginseng. These results could help to understand the embryo development in Korean ginseng.

• 한국어병학회지
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• 제23권2호
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• pp.229-238
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• 2010

We constructed a rock bream (Oplegnathus fasciatus) liver cDNA library and a total of 1533 expressed sequence tag (EST) clones were generated. Gene annotation procedures and homology searches of the sequenced ESTs were analyzed using BLASTX. Of the 1533 EST clones, 1165 different ESTs showed significant homology to previously described genes while 368 ESTs were unidentified, hypothetical, or unnamed proteins. Encoding 106 different sequences were identified as putative bio-defense genes or genes associated with immune response.