• Molecules and Cells
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• 제40권2호
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• pp.100-108
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• 2017

Cathepsin F, which is encoded by CTSF, is a cysteine proteinase ubiquitously expressed in several tissues. In a previous study, novel transcripts of the CTSF gene were identified in the crab-eating monkey deriving from the integration of an Alu element-AluYRa1. The occurrence of AluYRa1-derived alternative transcripts and the mechanism of exonization events in the CTSF gene of human, rhesus monkey, and crabeating monkey were investigated using PCR and reverse transcription PCR on the genomic DNA and cDNA isolated from several tissues. Results demonstrated that AluYRa1 was only integrated into the genome of Macaca species and this lineage-specific integration led to exonization events by producing a conserved 3' splice site. Six transcript variants (V1-V6) were generated by alternative splicing (AS) events, including intron retention and alternative 5' splice sites in the 5' and 3' flanking regions of CTSF_AluYRa1. Among them, V3-V5 transcripts were ubiquitously expressed in all tissues of rhesus monkey and crab-eating monkey, whereas AluYRa1-exonized V1 was dominantly expressed in the testis of the crab-eating monkey, and V2 was only expressed in the testis of the two monkeys. These five transcript variants also had different amino acid sequences in the C-terminal region of CTSF, as compared to reference sequences. Thus, species-specific Alu-derived exonization by lineage-specific integration of Alu elements and AS events seems to have played an important role during primate evolution by producing transcript variants and gene diversification.

• Genomics & Informatics
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• 제5권4호
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• pp.174-178
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• 2007

The earliest stages of mammalian embryogenesis are governed by the activity of maternally inherited transcripts and proteins. Cytoplasmic polyadenylation of selected maternal mRNA has been reported to be a major control mechanism of delayed translation during preimplantation embryogenesis in mice. The presence of cis-elements required for cytoplasmic polyadenylation (e.g., CPE) can serve as a useful tag in the screening of maternal genes partaking in key functions in the transcriptionally dormant egg and early embryo. However, due to its relative simplicity, UA-rich sequences satisfying the canonical rule of known CPE consensus sequences are often found in the 3'-UTR of maternal transcripts that do not actually undergo cytoplasmic polyadenylation. In this study, we developed a method to confirm the validity of candidate CPE sequences in a given gene by a multiplex comparison of 3'-UTR sequences between mammalian homologs. We found that genes undergoing cytoplasmic polyadenylation tend to create a conserved block around the CPE, while CPE-like sequences in the 3'-UTR of genes lacking cytoplasmic polyadenylation do not exhibit such conservation between species. Through this cross-species comparison, we also identified an alternative CPE in the 3'-UTR of tissue-type plasminogen activator (tPA), which is more likely to serve as a functional element. We suggest that verification of CPEs based on sequence conservation can provide a convenient tool for mass screening of factors governing the earliest processes of mammalian embryogenesis.

• 식물병연구
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• 제10권4호
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• pp.241-247
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• 2004

Cucumber mosaic virus(CMV)-Paf 계통에 포함된 satellite RNA(Paf-satRNA)는 CMV의 병징을 완화시키는 약독병징 관련 유전자로 작용하였다(Choi 등, 2001). 이 연구는 Paf-satRNA의 약독병징 관련 유전자의 도메인을 확인하기 위하여, 고추에서 chlorosis 병징을 발현하는 PepY-satRNA와 키메라 satRNA를 구축하여 분석하였다. 두 종의 satRNA의 염기서열을 비교한 결과, 분자크기가 큰 PepY-satRNA에서 10염기의 삽입이 발견되기는 하였지만, 양 말단영역의 염기는 비교적 안정된 conserved sequence를 보였다. 그러나 이들 satRNA의 중간영역에 존재하는 염기서열, 즉 5' 말단의 81번째 염기로부터 113번째, 그리고 183번째 염기부터 265번째 염기까지의 영역에서는 많은 변화를 나타냈다. 약독병징과 관련된 도메인을 확인하기 위하여 구축한 각 satRNA 및 키메라 satRNA의 cDNA로부터 transcript RNA를 전사시키고, 전사된 각 satRNA transcript를 CMV-Fny의 게놈RNA1, RNA2 및 RNA3의 transcript와 혼합한 후 N. benthamiana에 접종하였다. 그 결과 RT-PCR에 의해서 모든 satRNA-cDNA로부터 전사된 transcript의 감염성이 확인되었으며, Paf-satRNA 및 키메라 Paf(H/N)-satRNA와 PepY(N/A)-satRNA를 접종한 N. benthamiana에서는 모두 약한 모자이크 또는 무병징 감염의 특성을 보였다. 이와는 대조적으로 PepY-satRNA 및 키메라 PepY(H/N)-satRNA와 Paf(N/A)-satRNA를 접종한 식물에서는 전형적인 모자이크 증상과 식물체의 위축을 동반하였다. 이들 각 키메라 satRNA에 감염된 N. benthamiana를 접종원으로 고추에 접종한 결과, Paf-satRNA와 혼합한 CMV-Fny를 접종한 고추에서는 무병징에 가까운 약한 모자이크 증상이 발현되었고, PepY-satRNA를 접종한 고추는 뚜렷한 chlorosis의 모자이크 증상이 발현되었다. 한편 이들 두 종 satRNA의 키메라, Paf(H/N)-satRNA와 PepY(N/A)-satRNA를 접종한 고추에서는 모두 약한 모자이크 또는 무병징 감염의 특성을 보였고, PepY(H/N)-satRNA와 Paf(N/A)-satRNA를 접종한 식물에서는 전형적인 chlorosis의 모자이크 증상과 식물체의 위축을 동반하였다. 이와 같은 결과를 종합해 보았을 때, N. benthamiana에서와 마찬가지로 Paf-satRNA의 약독병징과 관련된 유전자의 도메인은 HpaI-NarI 영역에 존재한다는 것을 나타냈다.

• 한국산림과학회지
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• 제94권4호통권161호
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• pp.236-242
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• 2005

다양한 광조건에서 식물의 생장조절에 관여하는 광수용체인 phytochrome B(PhyB) 유전자를 교잡종 포플러 수항1호에서 분리하였다. 염기서열분석 결과, PhyB cDNA는 길이가 3,456bp 이었으며 1,156개의 아미노산으로 구성된 단백질을 암호화하고 있는 것으로 나타났다. PhyB 단백질은 아미노산 수준에서 Populus balsamfera PhyB1과 98%의 높은 상동성을 나타내었다. Northern blot 분석 결과, PhyB 유전자는 광조건에서는 높은 수준으로 발현되지만, 암조건에서는 발현되지 않는 것으로 나타났다. 본 연구의 결과들을 종합하여 볼 때 PhyB는 빛에 의하여 발현이 유도되며 광수용체 역할을 하는 것으로 여겨진다.

• ALGAE
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• 제26권3호
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• pp.229-235
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• 2011

Spliced leader (SL) trans-splicing is a mRNA processing mechanism in dinoflagellate nuclear genes. Although studies have identified a short, conserved dinoflagellate SL (dinoSL) sequence (22-nt) in their nuclear-encoded transcripts, whether the majority of nuclear-coded transcripts in dinoflagellates have the dinoSL sequence remains doubtful. In this study, we investigated dinoSL-containing gene transcripts using 454 pyrosequencing data (Cochlodinium polykrikoides, 93 K sequence reads, 31 Mb; Prorocentrum minimum, 773 K sequence reads, 291 Mb). After making comparisons and performing local BLAST searches, we identified dinoSL for one C. polykrikoides gene transcript and eight P. minimum gene transcripts. This showed transcripts containing the dinoSL sequence were markedly fewer in number than the total expressed sequence tag (EST) transcripts. In addition, we found no direct evidence to prove that most dinoflagellate nuclear-coded transcripts have this dinoSL sequence.

• 약학회지
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• 제49권3호
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• pp.205-211
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• 2005

The 3' UTR (3' untranslated region) plays important roles in controlling gene expression through regulating 3' polyadenylation, mRNA export, subcellular localization, translational efficiency, and mRNA stability. Changes in the 3' UTR sequence in an expressed transcript can result in functional changes of the genes that are expressed in pathological conditions compared with those genes expressed in normal physiologic conditions. A genome-wide survey of 3' UTR variation was performed for the genes expressed during hematopoietic differentiation from CD34+ stem/progenitor cells to CD 15 + myeloid progenitor cells. Wide-spread differential usage of the 3' UTR was observed from the genes expressed during this cellular transition. This study implies that the 3' UTR can be a highly coordinated region for post-transcriptional regulation of the function of expressed genes.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 추계학술발표대회
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• pp.1330-1332
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• 2012

생물정보학 데이터를 분석하는 과정에서 서열 데이터의 시각화는 연구자에게 방대한 서열 데이터의 특성을 눈으로 쉽게 이해하기 위한 필수 과정이다. 대조 실험 데이터나 다중 서열 데이터를 시각화해 주는 많은 도구들이 있지만 방대한 유전체 서열에서 사용자가 원하는 다중 데이터간의 비교 영역을 찾아서 시각화해주는 기능이 부족한 것이 현 상황이다. 본 논문은 불리언 질의를 통해서 다중 전사체 서열을 효율적으로 비교하고 그 결과를 시각화해주는 방법을 제안한다.

• Molecules and Cells
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• 제40권4호
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• pp.262-270
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• 2017

MicroRNAs (miRNAs) are single-stranded, small RNAs (21-23 nucleotides) that function in gene silencing and translational inhibition via the RNA interference mechanism. Most miRNAs originate from host genomic regions, such as intergenic regions, introns, exons, and transposable elements (TEs). Here, we focused on the palindromic structure of medium reiteration frequencies (MERs), which are similar to precursor miRNAs. Five MER consensus sequences (MER5A1, MER53, MER81, MER91C, and MER117) were matched with paralogous transcripts predicted to be precursor miRNAs in the horse genome (equCab2) and located in either intergenic regions or introns. The MER5A1, MER53, and MER91C sequences obtained from RepeatMasker were matched with the eca-miR-544b, eca-miR-1302, and eca-miR-652 precursor sequences derived from Ensembl transcript database, respectively. Each precursor form was anticipated to yield two mature forms, and we confirmed miRNA expression in six different tissues (cerebrum, cerebellum, lung, spleen, adrenal gland, and duodenum) of one thoroughbred horse. MER5A1-derived miRNAs generally showed significantly higher expression in the lung than in other tissues. MER91C-derived miRNA-5p also showed significantly higher expression in the duodenum than in other tissues (cerebellum, lung, spleen, and adrenal gland). The MER117-overlapped expressed sequence tag generated polycistronic miRNAs, which showed higher expression in the duodenum than other tissues. These data indicate that horse MER transposons encode miRNAs that are expressed in several tissues and are thought to have biological functions.

• Plant Biotechnology Reports
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• 제4권3호
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• pp.185-192
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• 2010

The Arabidopsis ${\omega}$-3 fatty acid desaturase (AtFAD7) catalyzes the synthesis of trienoic fatty acids (TA). A transgenic tobacco line, T15, was produced by a sense AtFAD7 construct and showed a cosuppression-like phenotype, namely extremely low TA levels. The sequence similarity between AtFAD7 and a tobacco ortholog gene, NtFAD7, was moderate (about 69%) in the coding sequences. AtFAD7 siRNAs accumulated at a high level, and both AtFAD7 and NtFAD7 mRNAs are degraded in T15 plants. The low-TA phenotype in T15 was dependent on a tobacco RNA-dependent RNA polymerase6 (NtRDR6). We also produced tobacco RNAi plants targeting AtFAD7 gene sequences. The AtFAD7 siRNA level was trace, which was associated with a slight reduction in leaf TA level. Unexpectedly, this RNAi plant showed an increased NtFAD7 transcript level. To investigate the effect of translational inhibition on stability of the NtFAD7 mRNAs, leaves of the wild-type tobacco plants were treated with a translational inhibitor, cycloheximide. The level of NtFAD7 mRNAs significantly increased after cycloheximde treatment. These results suggest that the translational inhibition by low levels of AtFAD7 siRNAs or by cycloheximide increased stability of NtFAD7 mRNA. The degree of silencing by an RNAi construct targeting the AtFAD7 gene was increased by co-existence of the AtFAD7 transgene, where NtRDR6-dependent amplification of siRNAs occurred. These results indicate that NtRDR6 can emphasize silencing effects in both cosuppression and RNAi.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.620-627
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• 2004

On the foundation of a database of genome sequences and protein analyses, the ability to clone a gene based on a peptide analysis is becoming more feasible and effective for identifying a specific gene and its protein product of interest. As such, the current study conducted a protein analysis using 2-D PAGE followed by MALDI- TOF and ESI-MS to identify a highly expressed gene product of C. parasitica. A distinctive and highly expressed protein spot with a molecular size of 47.2 kDa was randomly selected and MALDI-TOF MS analysis was conducted. A homology search indicated that the protein appeared to be a fungal enolase (enol). Meanwhile, multiple alignments of fungal enolases revealed a conserved amino acid sequence, from which degenerated primers were designed. A screening of the genomic $\lambda$ library of C. parasitica, using the PCR amplicon as a probe, was conducted to obtain the full-length gene, while RT-PCR was performed for the cDNA. The E. coli-expressed eno 1 exhibited enolase enzymatic activity, indicating that the cloned gene encoded the C. parasitica enolase. Moreover, ESI-MS of two of the separated peptides resolved from the protein spot on 2-D PAGE revealed sequences identical to the deduced sequences, suggesting that the cloned gene indeed encoded the resolved protein spot. Northern blot analysis indicated a consistent accumulation of an eno1 transcript during the cultivation.