MultiSite Gateway Technology Is Useful for Donor DNA Plasmid Construction in CRISPR/Cas9-Mediated Knock-In System

The clustered regulatory interspaced short palindromic repeats (CRISPR)/Cas9 method is a powerful tool for genome editing, by introducing a DNA double-strand break (DSB) at the specific site. The gene knock-out can be achieved by the deletion or insertion at the CRISPR/Cas9-mediated DSB site by error-prone nonhomologous end joining repair in targeted cells. However, the gene knock-in is still difficult as compared to the knock-out, because of the low efficiency of homology directed repair with donor DNA in cells. Therefore, to efficiently select the knock-in cells, we developed a complicated donor DNA plasmid containing an antibiotic-resistance gene, in addition to the knock-in sequence and the two homology arms. MultiSite Gateway technology is a useful tool for constructing this complicated plasmid. We describe the MultiSite Gateway technology and provide an overview of the DSB repair pathways to clarify the knock-out and knock-in methods by the CRISPR/Cas9 system

ヤマガタ ダイガク イガクブ フゾク ビョウイン ニオケル デングネツ ノ ソウキ ハッケン

Dengue fever (DF) is an acute febrile disease caused by dengue virus, which was re-emerged in tropical regions in the past 20 years. The numbers of imported DF were 6 to 44 per year in the recent Japan. We report a Japanese member of non-governmental organization (NGO) with dengue fever (DF). The patient developed sudden onset of high fever after returning to Japan, followed by rash and thrombocytopenia. DF was confirmed by isolation of dengue virus from serum, a positive reverse-transcriptase polymerase chain reaction (RT-PCR) test, and a high titer of IgM antibody to dengue virus. Dengue virus infection should be included in the differential diagnosis of the patients, developing high fever, skin rash, and thrombocytopenia after returning from endemic area.　Key words: dengue, fever, thrombocytopenia, lymphocyt

Novel function of HATs and HDACs in homologous recombination through acetylation of human RAD52 at double-strand break sites

The p300 and CBP histone acetyltransferases are recruited to DNA double-strand break (DSB) sites where they induce histone acetylation, thereby influencing the chromatin structure and DNA repair process. Whether p300/CBP at DSB sites also acetylate non-histone proteins, and how their acetylation affects DSB repair, remain unknown. Here we show that p300/CBP acetylate RAD52, a human homologous recombination (HR) DNA repair protein, at DSB sites. Using in vitro acetylated RAD52, we identified 13 potential acetylation sites in RAD52 by a mass spectrometry analysis. An immunofluorescence microscopy analysis revealed that RAD52 acetylation at DSBs sites is counteracted by SIRT2- and SIRT3-mediated deacetylation, and that non-acetylated RAD52 initially accumulates at DSB sites, but dissociates prematurely from them. In the absence of RAD52 acetylation, RAD51, which plays a central role in HR, also dissociates prematurely from DSB sites, and hence HR is impaired. Furthermore, inhibition of ataxia telangiectasia mutated (ATM) protein by siRNA or inhibitor treatment demonstrated that the acetylation of RAD52 at DSB sites is dependent on the ATM protein kinase activity, through the formation of RAD52, p300/CBP, SIRT2, and SIRT3 foci at DSB sites. Our findings clarify the importance of RAD52 acetylation in HR and its underlying mechanism

The history of human populations in the Japanese Archipelago inferred from genome-wide SNP data with a special reference to the Ainu and the Ryukyuan populations

The Japanese Archipelago stretches over 4000 km from north to south, and is the homeland of the three human populations; the Ainu, the Mainland Japanese and the Ryukyuan. The archeological evidence of human residence on this Archipelago goes back to 430 000 years, and various migration routes and root populations have been proposed. Here, we determined close to one million single-nucleotide polymorphisms (SNPs) for the Ainu and the Ryukyuan, and compared these with existing data sets. This is the first report of these genome-wide SNP data. Major findings are: (1) Recent admixture with the Mainland Japanese was observed for more than one third of the Ainu individuals from principal component analysis and frappe analyses; (2) The Ainu population seems to have experienced admixture with another population, and a combination of two types of admixtures is the unique characteristics of this population; (3) The Ainu and the Ryukyuan are tightly clustered with 100% bootstrap probability followed by the Mainland Japanese in the phylogenetic trees of East Eurasian populations. These results clearly support the dual structure model on the Japanese Archipelago populations, though the origins of the Jomon and the Yayoi people still remain to be solved