• Title/Summary/Keyword: molecular genomics

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Mitochondrial noncoding RNA transport

  • Kim, Kyoung Mi;Noh, Ji Heon;Abdelmohsen, Kotb;Gorospe, Myriam
    • BMB Reports
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    • v.50 no.4
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    • pp.164-174
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    • 2017
  • Mitochondria are cytosolic organelles essential for generating energy and maintaining cell homeostasis. Despite their critical function, the handful of proteins expressed by the mitochondrial genome is insufficient to maintain mitochondrial structure or activity. Accordingly, mitochondrial metabolism is fully dependent on factors encoded by the nuclear DNA, including many proteins synthesized in the cytosol and imported into mitochondria via established mechanisms. However, there is growing evidence that mammalian mitochondria can also import cytosolic noncoding RNA via poorly understood processes. Here, we summarize our knowledge of mitochondrial RNA, discuss recent progress in understanding the molecular mechanisms and functional impact of RNA import into mitochondria, and identify rising challenges and opportunities in this rapidly evolving field.

A Database of Gene Expression Profiles of Korean Cancer Genome

  • Kim, Seon-Kyu;Chu, In-Sun
    • Genomics & Informatics
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    • v.13 no.3
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    • pp.86-89
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    • 2015
  • Because there are clear molecular differences entailing different treatment effectiveness between Korean and non-Korean cancer patients, identifying distinct molecular characteristics of Korean cancers is profoundly important. Here, we report a web-based data repository, namely Korean Cancer Genome Database (KCGD), for searching gene signatures associated with Korean cancer patients. Currently, a total of 1,403 cancer genomics data were collected, processed and stored in our repository, an ever-growing database. We incorporated most widely used statistical survival analysis methods including the Cox proportional hazard model, log-rank test and Kaplan-Meier plot to provide instant significance estimation for searched molecules. As an initial repository with the aim of Korean-specific marker detection, KCGD would be a promising web application for users without bioinformatics expertise to identify significant factors associated with cancer in Korean.

Bridging Comparative Genomics and DNA Marker-aided Molecular Breeding

  • Choi, Hong-Kyu;Cook, Douglas R.
    • Korean Journal of Breeding Science
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    • v.43 no.2
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    • pp.103-114
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    • 2011
  • In recent years, genomic resources and information have accumulated at an ever increasing pace, in many plant species, through whole genome sequencing, large scale analysis of transcriptomes, DNA markers and functional studies of individual genes. Well-characterized species within key plant taxa, co-called "model systems", have played a pivotal role in nucleating the accumulation of genomic information and databases, thereby providing the basis for comparative genomic studies. In addition, recent advances to "Next Generation" sequencing technologies have propelled a new wave of genomics, enabling rapid, low cost analysis of numerous genomes, and the accumulation of genetic diversity data for large numbers of accessions within individual species. The resulting wealth of genomic information provides an opportunity to discern evolutionary processes that have impacted genome structure and the function of genes, using the tools of comparative analysis. Comparative genomics provides a platform to translate information from model species to crops, and to relate knowledge of genome function among crop species. Ultimately, the resulting knowledge will accelerate the development of more efficient breeding strategies through the identification of trait-associated orthologous genes and next generation functional gene-based markers.

Characterization of rDNAs and Tandem Repeats in the Heterochromatin of Brassica rapa

  • Lim, Ki-Byung;de Jong, Hans;Yang, Tae-Jin;Park, Jee-Young;Kwon, Soo-Jin;Kim, Jung Sun;Lim, Myung-Ho;Kim, Jin A;Jin, Mina;Jin, Yong-Moon;Kim, Seog Hyung;Lim, Yong Pyo;Bang, Jae-Wook;Kim, Ho-Il;Park, Beom-Seok
    • Molecules and Cells
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    • v.19 no.3
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    • pp.436-444
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    • 2005
  • We describe the morphology and molecular organization of heterochromatin domains in the interphase nuclei, and mitotic and meiotic chromosomes, of Brassica rapa, using DAPI staining and fluorescence in situ hybridization (FISH) of rDNA and pericentromere tandem repeats. We have developed a simple method to distinguish the centromeric regions of mitotic metaphase chromosomes by prolonged irradiation with UV light at the DAPI excitation wavelength. Application of this bleached DAPI band (BDB) karyotyping method to the 45S and 5S rDNAs and 176 bp centromere satellite repeats distinguished the 10 B. rapa chromosomes. We further characterized the centromeric repeat sequences in BAC end sequences. These fell into two classes, CentBr1 and CentBr2, occupying the centromeres of eight and two chromosomes, respectively. The centromere satellites encompassed about 30% of the total chromosomes, particularly in the core centromere blocks of all the chromosomes. Interestingly, centromere length was inversely correlated with chromosome length. The morphology and molecular organization of heterochromatin domains in interphase nuclei, and in mitotic and meiotic chromosomes, were further characterized by DAPI staining and FISH of rDNA and CentBr. The DAPI fluorescence of interphase nuclei revealed ten to twenty conspicuous chromocenters, each composed of the heterochromatin of up to four chromosomes and/or nucleolar organizing regions.

Prediction of Mammalian MicroRNA Targets - Comparative Genomics Approach with Longer 3' UTR Databases

  • Nam, Seungyoon;Kim, Young-Kook;Kim, Pora;Kim, V. Narry;Shin, Seokmin;Lee, Sanghyuk
    • Genomics & Informatics
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    • v.3 no.3
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    • pp.53-62
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    • 2005
  • MicroRNAs play an important role in regulating gene expression, but their target identification is a difficult task due to their short length and imperfect complementarity. Burge and coworkers developed a program called TargetScan that allowed imperfect complementarity and established a procedure favoring targets with multiple binding sites conserved in multiple organisms. We improved their algorithm in two major aspects - (i) using well-defined UTR (untranslated region) database, (ii) examining the extent of conservation inside the 3' UTR specifically. Average length in our UTR database, based on the ECgene annotation, is more than twice longer than the Ensembl. Then, TargetScan was used to identify putative binding sites. The extent of conservation varies significantly inside the 3' UTR. We used the 'tight' tracks in the UCSC genome browser to select the conserved binding sites in multiple species. By combining the longer 3' UTR data, TargetScan, and tightly conserved blocks of genomic DNA, we identified 107 putative target genes with multiple binding sites conserved in multiple species, of which 85 putative targets are novel.

Genome-wide Response of Normal WI-38 Human Fibroblast Cells to 1,763 MHz Radiofrequency Radiation

  • Im, Chang-Nim;Kim, Eun-Hye;Park, Ae-Kyung;Park, Woong-Yang
    • Genomics & Informatics
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    • v.8 no.1
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    • pp.28-33
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    • 2010
  • Increased exposure of human to RF fields has raised concerns for its potential adverse effects on our health. To address the biological effects of RF radiation, we used genome wide gene expression as the indicator. We exposed normal WI-38 human fibroblast cells to 1763 MHz mobile phone RF radiation at a specific absorption rate (SAR) of 60 W/kg with an operating cooling system for 24 h. There were no alterations in cell numbers or morphology after RF exposure. Through microarray analysis, we identified no differentially expressed genes (DEGs) at the 0.05 significance level after controlling for multiple testing errors with the Benjaminiochberg false discovery rate (BH FDR) method. Meanwhile, 82 genes were differentially expressed between RF-exposed cells and controls when the significance level was set at 0.01 without correction for multiple comparisons. We found that 24 genes (0.08% of the total genes examined) were changed by more than 1.5-fold on RF exposure. However, significant enrichment of any gene set or pathway was not observed from the functional annotation analysis. From these results, we did not find any evidence that non-thermal RF radiation at a 60-W/kg SAR significantly affects cell proliferation or gene expression in WI-38 cells.