Yasuyuki Ohkawa

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The initiation of cellular differentiation involves alterations in gene expression that depend on chromatin changes, at the level of both higher-order structures and individual genes. Consistent with this, chromatin-remodelling enzymes have key roles in differentiation and development. The functions of ATP-dependent chromatin-remodelling enzymes have been(More)
A procedure for direct gene transfer into isolated microspores of rapeseed (Brassica napus L.) and the production of fertile transgenic plants is presented. By modifying the microspore culture method and adopting the firefly luciferase (Luc) gene as a non-destructive marker, we could obtain stably transformed androgenetic embryos from bombarded microspores.(More)
The induction of sister chromatid exchanges (SCE) and mutation at the hypoxanthine-guanine phosphoribosyl transferase locus and toxicities of 40 different chemical and physical agents were examined on Chinese hamster V79 cells. These agents included mono-, di-, tri-, and polyfunctional alkylating agents, intercalators, gamma-rays, and UV light irradiation.(More)
Traumatic injury in the central nervous system induces inflammation; however, the role of this inflammation is controversial. Precise analysis of the inflammatory cells is important to gain a better understanding of the inflammatory machinery in response to neural injury. Here, we demonstrated that leukotriene B4 plays a significant role in mediating(More)
The activation of muscle-specific gene expression requires the coordinated action of muscle regulatory proteins and chromatin-remodeling enzymes. Microarray analysis performed in the presence or absence of a dominant-negative BRG1 ATPase demonstrated that approximately one-third of MyoD-induced genes were highly dependent on SWI/SNF enzymes. To understand(More)
In eukaryotic cells, post-translational histone modifications have an important role in gene regulation. Starting with early work on histone acetylation, a variety of residue-specific modifications have now been linked to RNA polymerase II (RNAP2) activity, but it remains unclear if these markers are active regulators of transcription or just passive(More)
BACKGROUND We previously identified unsaturated (16:1, 18:1, and 18:2) but not saturated (12:0, 14:0, 16:0, and 18:0) lysophosphatidic acids (LPAs) as potent factors for vascular smooth muscle cell (VSMC) dedifferentiation. Unsaturated LPAs strongly induce VSMC dedifferentiation via the coordinated activation of the extracellular signal-regulated kinase(More)
Skeletal muscle differentiation requires the coordinated activity of transcription factors, histone modifying enzymes, and ATP-dependent chromatin remodeling enzymes. The type II protein arginine methyltransferase Prmt5 symmetrically dimethylates histones H3 and H4 and numerous nonchromatin proteins, and prior work has implicated Prmt5 in transcriptional(More)
Myogenin is required not for the initiation of myogenesis but instead for skeletal muscle formation through poorly understood mechanisms. We demonstrate in cultured cells and, for the first time, in embryonic tissue, that myogenic late genes that specify the skeletal muscle phenotype are bound by MyoD prior to the initiation of gene expression. At the onset(More)