• Korean Journal of Agricultural Science
• /
• v.44 no.3
• /
• pp.318-324
• /
• 2017

With the development of next-generation sequencing (NGS), a cutting-edge technology, genotype-by-sequencing (GBS) became available at a low cost per sample. GBS makes it possible to customize the process of library preparation to obtain high-quality single nucleotide polymorphisms (SNPs) in the most efficient way. However, a GBS library is hard to construct due to fine-tuning of concentration of each reagent and set-up. The major reason for this is the presence of undigested genomic DNA (gDNA) owing to the efficiency of different restriction enzymes for different species with unknown reasons. Therefore, this proof-concept study is to demonstrate the unpredictable patterns of enzyme digestion from various plants in order to make the reader aware of the caution needed when choosing restriction enzymes for their GBS library preparations. Indeed, no pattern was found for the digestibility of gDNA samples and restriction enzymes in the current study. We suggest that more data should be accumulated on this matter to help researchers who want to apply GBS technologies in a variety of genetic approaches.

• Mycobiology
• /
• v.28 no.4
• /
• pp.171-176
• /
• 2000

We have cloned a ${\alpha}-COP$ homolog, ancop, from Aspergillus nidulans by colony hybridization of chromosome specific library using ${\alpha}-COP$ homologous fragment as a probe. The probe DNA was amplified with degenerated primers designed by comparison of conserved region of the amino acid sequences of Saccharomyces cerevisiae ${\alpha}-COP$, Homo sapiens HEP-COP, and Drosophila melanogaster ${\alpha}-COP$. Full length cDNA clone was also amplified by RT-PCR. Comparison of genomic DNA sequence with cDNA sequence obtained by RT-PCR revealed 7 introns. Amino acid sequence similarity search of the anCop with other ${\alpha}-COPs$ gave an overall identity of 52% with S. cerevisiae, 47% with human and bovine, 45% with Drosophila and Arabidopsis. In upstream region from the transcription start site, a putative TATA and CAAT motif were also identified.

• Asian-Australasian Journal of Animal Sciences
• /
• v.6 no.4
• /
• pp.541-547
• /
• 1993

A phage clone containing the partial ${\alpha}_{S1}$-casein gene was isolated from a bovine genomic library by using mixed probes of ovine ${\alpha}_{S1}$-, ${\beta}$- and ${\kappa}$-casein cDNAs. Restriction enzyme mapping analysis for 14.6 kb revealed that the map was in conflict with the report of Meade et al. (1990), especially in the 3'-end fragment. Sequence analysis of 12.6 kb revealed a high AT/GC ratio (1.64); we have identified eight exon sequences according to the bovine ${\alpha}_{S1}$-casein cDNA sequence. The same exon/intron splice junction sequence was observed between these exons. We suggest that the bovine ${\alpha}_{S1}$-casein gene night contain a minimum of 18 exons and the full length is approximately 18-19 kb.

• Journal of Periodontal and Implant Science
• /
• v.32 no.2
• /
• pp.269-280
• /
• 2002

The purpose of this study is to develop species-specific DNA probes and polymerase chain reaction (PCR) primers for detection and identification of Prevotella nigrescens (P. nigrescens) 9336. This study procedure includes (1) whole-genomic DNA extraction of P. nigrescens 9336 (2) construction of the genomic DNA library, (3) screening of strain-specific DNA probe by reverse Dot Hybridization method, (4) confirmation of strain-specific DNA probe by Southern blot analysis, (5) determination of nucleotide sequences of strain-specific DNA probe. Thirty-five restriction fragments of P. nigrescens 9336 genomic DNA digested with the Hind III were obtained. Reverse dot hybridization and Southern blot analysis data showed that three of them, Pn10, Pn23, and Pn35, could be P. nigrescens 9336-specific DNA probes. These data indicated that these DNA probes could be useful in detection and identification of the P. nigrescens 9336.

• Korean Journal of Microbiology
• /
• v.30 no.4
• /
• pp.246-251
• /
• 1992

Molccular cloning of nod genes from Bradvrhizobium sp. SNU001, a nitrogen-fixing symbiont isolated from thc root nodules of soybean (Clycine trim) . was carried out. nod genes were found to be located on thc genome of the symbiont by gcnomic hybridization with 4.5 kb EcoRI/HndIII fragment (nod DABC) of Rhizohium meliloti as probe. Genomic library of this symbiont was constructed using h phage EMBL3-BanlHI vector. from which five nod positive clones were sclectcd by primary and secondary screening methods. The partial restriction map of inserted genomic DNA of h CNS-l(c1one 2) was constructed. and 3.9 kh Bun7HI fragment. which showed strong hybridization signal to the probe, was subcloned into pBS KS(+) plasmid vector. Partial restriction inap ot' a selected subclone (pBjCNS-I) was constructed and nod DABC was found to be located on the 1.8 kb KpnI/Sacl fragment of this subclone.

• Genomics & Informatics
• /
• v.20 no.1
• /
• pp.2.1-2.11
• /
• 2022

The method of single-cell RNA sequencing has been rapidly developed, and numerous experiments have been conducted over the past decade. Their results allow us to recognize various subpopulations and rare cell states in tissues, tumors, and immune systems that are previously unidentified, and guide us to understand fundamental biological processes that determine cell identity based on single-cell gene expression profiles. However, it is still challenging to understand the principle of comprehensive gene regulation that determines the cell fate only with transcriptome, a consequential output of the gene expression program. To elucidate the mechanisms related to the origin and maintenance of comprehensive single-cell transcriptome, we require a corresponding single-cell epigenome, which is a differentiated information of each cell with an identical genome. This review deals with the current development of single-cell epigenomic library construction methods, including multi-omics tools with crucial factors and additional requirements in the future focusing on DNA methylation, chromatin accessibility, and histone post-translational modifications. The study of cellular differentiation and the disease occurrence at a single-cell level has taken the first step with single-cell transcriptome and is now taking the next step with single-cell epigenome.

• IMMUNE NETWORK
• /
• v.2 no.4
• /
• pp.233-241
• /
• 2002

Background: Monoclonal antibodies (mAb) of rodent origin are produced with ease by hybridoma fusion technique, and have been successfully used as therapeutic reagents for humans after humanization by genetic engineering. However, utilization of these antibodies for therapeutic purpose has been limited by the fact that they act as immunogens in human body causing undesired side effects. So far, there have been several attempts to produce human mAbs for effective in vivo diagnostic or therapeutic reagents including the use of humanized xenomouse that is generated by mating knockout mice which lost Ig heavy and light chain genes by homologous recombination and transgenic mice having both human Ig heavy and light gene loci in their genome. Methods: Genomic DNA fragments of mouse Ig heavy and light chain were obtained from a mouse brain ${\lambda}$ genomic library by PCR screening and cloned into a targeting vector with ultimate goal of generating Ig knockout mouse. Results: Through PCR screening of the genomic library, three heavy chain and three light chain Ig gene fragments were identified, and restriction map of one of the heavy chain gene fragments was determined. Then heavy chain Ig gene fragments were subcloned into a targeting vector. The resulting construct was introduced into embryonic stem cells. Antibiotic selection of transfected cells is under the progress. Conclusion: Generation of xenomouse is particularly important in medical biotechnology. However, this goal is not easily achieved due to the technical difficulties as well as huge financial expenses. Although we are in the early stage of a long-term project, our results, at least, partially contribute the successful generation of humanized xenomouse in Korea.

• Journal of Microbiology
• /
• v.41 no.1
• /
• pp.46-51
• /
• 2003

RAD6 in yeast mediates postreplication DNA repair and is responsible for DNA-damage induced mutations. RAD6 encodes ubiquitin-conjugating enzyme that is well conserved among eukaryotic organisms. However, the molecular targets and consequences of their ubiquitination by Rad6 have remained elusive. In Aspergillus nidulans, a RAD6 homolog has been isolated and shown to be an allele of uvs). We screened a CDNA library to isolate UVSJ-interacting proteins by the yeast two-hybrid system. JIPA was identified as an interactor of UVSJ. Their interaction was confirmed in vitro by a GST-pull down assay. JIPA was also able to interact with mutant UVSJ proteins, UVSJl and the active site cysteine mutant UVSJ-C88A. The N- and the C-terminal regions of UVSJ required for the interaction with UVSH, a RAD18 homolog of yeast which physically interacts with Rad6, were not necessary for the JIPA and UVSJ interactions. About 1.4 kb jipA transcript was detected in Northern analysis and its amount was not significantly increased in response to DNA-damaging agents. A genomic DNA clone of the jipA gene was isolated from a chromosome I specific genomic library by PCR-sib selection. Sequence determination of genomic and cDNA of jipA revealed an ORF of 893 bp interrupted by 2 introns, encoding a putative polypeptide of 262 amino acids. JIPA has 33% amino acid sequence identity to TIP41 of Saccharomyces cerevisiae which negatively regulates the TOR signaling pathway.

• Korean Journal of Veterinary Research
• /
• v.33 no.3
• /
• pp.479-486
• /
• 1993

This study was attempted co develope a method for detection of Theileria sergenti infection on the basis of hybridization of parasite DNA with a probe. For construction of a T sergenti genomic library, T sergenti DNA was digested completely with Bam-HI and the fragments were ligated into the Bam-HI site of pUC-19 before transformation of Escherichia colistrain JM83. To detect clones containing the parasite's DNA sequences, a genomic DNA library of T sergenti constructed in pUC-19 was screened by cracking and Southern hybridization. Seven colonies were chosen from 29 colonies which were screened by transformation of Escherichia coli strain JM83. Seven transformants were comfirmed from seven colonies by cracking. The sizes of transformants were about 5Kb, 5.7Kb, 4.3Kb, 7.75Kb, 7.85Kb, 5.8Kb, 3.8Kb, respectively. DNA inserts, T sergenti DNA, and bovine DNA were hybridized with radio-labelled T sergenti DNA. Two($pT_1$, $pT_1$) of the seven inserts and T sergenti DNA reacted strongly but another 5 inserts and bovine DNA showed weak reation. All of the DNA inserts were not reaction, but T sergenti DNA were very weakly and bovine DNA were strongly reacted to hybridization with radio-labelled bovine DNA. Therefore, we obtained total 7 T sergenti DNA fragments in this study.

• Journal of Microbiology and Biotechnology
• /
• v.7 no.2
• /
• pp.157-159
• /
• 1997

A 340-bp chitin synthase gene(CHS) fragment was cloned from the genomic DNA of Pyricularia oryzae using a PCR process with two primer DNAs corresponding to highly conserved sequences within fungal CHS genes. The entire DNA nucleotide sequences of the cloned DNA fragment were determined and analyzed. The amino acid sequences deduced from the nucleotide sequence of the amplified DNA fragment showed 86% homology to that of the Aspergillus fumigatus CHSE gene (9). Using this PCR-amplified DNA, about 2.3 kb of including the PCR fragment of CHSE gene was cloned from genomic library.