• Asian-Australasian Journal of Animal Sciences
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• v.21 no.5
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• pp.745-753
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• 2008

Gene-manipulated mice were discovered for the first time about a quarter century ago. Since then, numerous sophisticated technologies have been developed and applied to answer key questions about the fundamental roles of the genes of interest. Functional genomics can be characterized into gain-of-function and loss-of-function, which are called transgenic and knock-out studies, respectively. To make transgenic mice, the most widely used technique is the microinjection of transgene-containing vectors into the embryonic pronucleus. However, there are critical drawbacks: namely position effects, integration of unknown copies of a foreign gene, and instability of the foreign DNA within the host genome. To overcome these problems, the ROSA26 locus was used for the knock-in site of a transgene. Usage of this locus is discussed for the gain of function study as well as for several brilliant approaches such as conditional/inducible transgenic system, reproducible/inducible knockdown system, specific cell ablation by Cre-mediated expression of DTA, Cre-ERTM mice as a useful tool for temporal gene regulation, MORE mice as a germ line delete and site specific recombinase system. Techniques to make null mutant mice include complicated steps: vector design and construction, colony selection of embryonic stem (ES) cells, production of chimera mice, confirmation of germ line transmission, and so forth. It is tedious and labor intensive work and difficult to approach. Thus, it is not readily accessible by most researchers. In order to overcome such limitations, technical breakthroughs such as reporter knock-in and gene knock-out system, production of homozygous mutant ES cells from a single targeting vector, and production of mutant mice from tetraploid embryos are developed. With these upcoming progresses, it is important to consider how we could develop these systems further and expand to other animal models such as pigs and monkeys that have more physiological similarities to humans.

• BMB Reports
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• v.28 no.4
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• pp.368-373
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• 1995

The upstream regulatory region (URR) of bovine papillomavirus type 1 (BPV) contains promoters and a conditional transcriptional enhancer that is trans-activated by the viral E2 protein. After deleting the 5' and 3' ends of BPV URR, BamHI linkers were inserted into several positions of BPV URR without causing an addition or a deletion of URR sequences. Most linker scanning mutations did not show any effects on the transcription of P7940 and P89 promoters in BPV URR. However, several mutants showed reduced transcriptional activities. Based on our results we found that the AP-2 and Sp1 binding sites were important for basal level transcription of BPV URR in the absence of the E2 protein and that the CTF/NF-1 site is dispensable for E2 transactivation of BPV URR transcription.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.239-248
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• 2015

The nature of molecular mechanisms governing embryonic cell block is largely unknown, but recent reports have demonstrated that proper execution of programmed cell death is crucial for this process. The main objective of this study is to determine effects of programmed cell death on porcine oocytes development in vitro after parthenogenesis. Among the blastocysts matured in 3MA, MAP1LC3A and ATG5 RNA gene expression level increased in the order of Cyst < 3MA < RP. However, Casp-3 and TNF-r RNA gene expression level decreased in the order of RP < 3MA < Cyst. Expression of mTOR within the RP-cultured blastocyst was the most highly to the inner cell mass, while 3MA-cultured blastocyst showed very lowest expression in inner cell mass. The expression of mTOR showed a pattern opposite to that of MAP1LC3A. That is, its expression was the lowest in Cyst group. When the enzymatic activity of MMP-2 and MMP-9 was assessed in culture, the level of active MMP-9 was higher expression in the medium of each RP treatment group, with the level of another treatment group being relatively higher. Analyses of TIMP-2 and TIMP-3 revealed that their expression was higher in groups that did not receive RP treatment. More specifically, the level of TIMP-2 was not affected by Cyst treatment, while the level of TIMP-3 was higher in 3MA and RP treatment group. There was highly cell division activation efficiency of parthenogenesis on cultured system of RP supplement IVC medium. Therefore, these results suggest that embryo development was significantly increased in conditional culture medium with active autophagy as compared to common cultured condition. Further investigation of this distinction may enable the development of innovative improvements for the production of porcine somatic cell nuclear transfer.

• Interdisciplinary Bio Central
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• v.2 no.4
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• pp.15.1-15.5
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• 2010

RIKEN BioResource Center (BRC) has collected, preserved, conducted quality control of, and distributed mouse resources since 2002 as the core facility of the National BioResource Project by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. Our mouse resources include over 5,000 strains such as humanized disease models, fluorescent reporters, and knockout mice. We have developed novel mouse strains such as tissue-specific Cre-drivers and optogenetic strains that are in high demand by the research community. We have removed all our specified pathogens from the deposited mice and used our quality control tests to examine their genetic modifications and backgrounds. RIKEN BRC is a founding member of the Federation of International Mouse Resources and the Asian Mouse Mutagenesis and Resource Association, and provides mouse resources to the one-stop International Mouse Strain Resource database. RIKEN BRC also participates in the International Gene Trap Consortium, having registered 713 gene-trap clones and their sequences in a public library, and is an advisory member of the CREATE (Coordination of resources for conditional expression of mutated mouse alleles) consortium which represents major European and international mouse database holders for the integration and dissemination of Cre-driver strains. RIKEN BRC provides training courses in the use of advanced technologies for the quality control and cryopreservation of mouse strains to promote the effective use of mouse resources worldwide.

• Molecules and Cells
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• v.27 no.4
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• pp.475-480
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• 2009

The transcription of soybean (Glycine max) calmodulin isoform-4 (GmCaM-4) is dramatically induced within 0.5 h of exposure to pathogen or NaCl. Core cis-acting elements that regulate the expression of the GmCaM-4 gene in response to pathogen and salt stress were previously identified, between -1,207 and -1,128 bp, and between -858 and -728 bp, in the GmCaM-4 promoter. Here, we characterized the properties of the DNA-binding complexes that form at the two core cis-acting elements of the GmCaM-4 promoter in pathogen-treated nuclear extracts. We generated GUS reporter constructs harboring various deletions of approximately 1.3-kb GmCaM-4 promoter, and analyzed GUS expression in tobacco plants transformed with these constructs. The GUS expression analysis suggested that the two previously identified core regions are involved in inducing GmCaM-4 expression in the heterologous system. Finally, a transient expression assay of Arabidopsis protoplasts showed that the GmCaM-4 promoter produced greater levels of GUS activity than did the CaMV35S promoter after pathogen or NaCl treatments, suggesting that the GmCaM-4 promoter may be useful in the production of conditional gene expression systems.

• Molecules and Cells
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• v.41 no.4
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• pp.362-372
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• 2018

High mobility group box 2 (HMGB2) is an abundant, chromatin-associated, non-histone protein involved in transcription, chromatin remodeling, and recombination. Recently, the HMGB2 gene was found to be significantly downregulated during senescence and shown to regulate the expression of senescent-associated secretory proteins. Here, we demonstrate that HMGB2 transcription is repressed by p21 during radiation-induced senescence through the ATM-p53-p21 DNA damage signaling cascade. The loss of p21 abolished the downregulation of HMGB2 caused by ionizing radiation, and the conditional induction of p21 was sufficient to repress the transcription of HMGB2. We also showed that the p21 protein binds to the HMGB2 promoter region, leading to sequestration of RNA polymerase and transcription factors E2F1, Sp1, and p300. In contrast, NF-Y, a CCAAT box-binding protein complex, is required for the expression of HMGB2, but NF-Y binding to the HMGB2 promoter was unaffected by either radiation or p21 induction. A proximity ligation assay results confirmed that the chromosome binding of E2F1 and Sp1 was inhibited by p21 induction. As HMGB2 have been shown to regulate premature senescence by IR, targeting the p21-mediated repression of HMGB2 could be a strategy to overcome the detrimental effects of radiation-induced senescence.

• Molecules and Cells
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• v.28 no.4
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• pp.321-329
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• 2009

Rapid production of nitric oxide (NO) and reactive oxygen species (ROS) has been implicated in the regulation of innate immunity in plants. A potato calcium-dependent protein kinase (StCDPK5) activates an NADPH oxidase StRBOHA to D by direct phosphorylation of N-terminal regions, and heterologous expression of StCDPK5 and StRBOHs in Nicotiana benthamiana results in oxidative burst. The transgenic potato plants that carry a constitutively active StCDPK5 driven by a pathogen-inducible promoter of the potato showed high resistance to late blight pathogen Phytophthora infestans accompanied by HR-like cell death and $H_2O_2$ accumulation in the attacked cells. In contrast, these plants showed high susceptibility to early blight necrotrophic pathogen Alternaria solani, suggesting that oxidative burst confers high resistance to biotrophic pathogen, but high susceptibility to necrotrophic pathogen. NO and ROS synergistically function in defense responses. Two MAPK cascades, MEK2-SIPK and cytokinesis-related MEK1-NTF6, are involved in the induction of NbRBOHB gene in N. benthamiana. On the other hand, NO burst is regulated by the MEK2-SIPK cascade. Conditional activation of SIPK in potato plants induces oxidative and NO bursts, and confers resistance to both biotrophic and necrotrophic pathogens, indicating the plants may have obtained during evolution the signaling pathway which regulates both NO and ROS production to adapt to wide-spectrum pathogens.

• Biomolecules & Therapeutics
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• v.29 no.3
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• pp.311-320
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• 2021

Accumulation of reactive oxygen species (ROS) is associated with the development of various diseases. However, the molecular mechanisms underlying oxidative stress that lead to such diseases like autosomal dominant polycystic kidney disease (ADPKD) remain unclear. Here, we observed that oxidative stress markers were increased in Pkd1f/f:HoxB7-Cre mice. Forkhead transcription factors of the O class (FOXOs) are known key regulators of the oxidative stress response, which have been observed with the expression of FoxO3a in an ADPKD mouse model in the present study. An integrated analysis of two datasets for differentially expressed miRNA, such as miRNA sequencing analysis of Pkd1 conditional knockout mice and microarray analysis of samples from ADPKD patients, showed that miR-132-3p was a key regulator of FOXO3a in ADPKD. miR-132-3p was significantly upregulated in ADPKD which directly targeted FOXO3 in both mouse and human cell lines. Interestingly, the mitochondrial gene Gatm was downregulated in ADPKD which led to a decreased inhibition of Foxo3. Overexpression of miR-132-3p coupled with knockdown of Foxo3 and Gatm increased ROS and accelerated cyst formation in 3D culture. This study reveals a novel mechanism involving miR-132-3p, Foxo3, and Gatm that is associated with the oxidative stress that occurs during cystogenesis in ADPKD.