Show simple item record

dc.contributor.authorImai, Ryosuke  Concept link
dc.contributor.authorNozaki, Tadasu  Concept link
dc.contributor.authorTani, Tomomi  Concept link
dc.contributor.authorKaizu, Kazunari  Concept link
dc.contributor.authorHibino, Kayo  Concept link
dc.contributor.authorIde, Satoru  Concept link
dc.contributor.authorTamura, Sachiko  Concept link
dc.contributor.authorTakahashi, Koichi  Concept link
dc.contributor.authorShribak, Michael  Concept link
dc.contributor.authorMaeshima, Kazuhiro  Concept link
dc.identifier.citationMolecular Biology of the Cell 28 (2017): 3349-3359en_US
dc.description© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Molecular Biology of the Cell 28 (2017): 3349-3359, doi:10.1091/mbc.E17-06-0359.en_US
dc.description.abstractIn eukaryotic cells, highly condensed inactive/silenced chromatin has long been called “heterochromatin.” However, recent research suggests that such regions are in fact not fully transcriptionally silent and that there exists only a moderate access barrier to heterochromatin. To further investigate this issue, it is critical to elucidate the physical properties of heterochromatin such as its total density in live cells. Here, using orientation-independent differential interference contrast (OI-DIC) microscopy, which is capable of mapping optical path differences, we investigated the density of the total materials in pericentric foci, a representative heterochromatin model, in live mouse NIH3T3 cells. We demonstrated that the total density of heterochromatin (208 mg/ml) was only 1.53-fold higher than that of the surrounding euchromatic regions (136 mg/ml) while the DNA density of heterochromatin was 5.5- to 7.5-fold higher. We observed similar minor differences in density in typical facultative heterochromatin, the inactive human X chromosomes. This surprisingly small difference may be due to that nonnucleosomal materials (proteins/RNAs) (∼120 mg/ml) are dominant in both chromatin regions. Monte Carlo simulation suggested that nonnucleosomal materials contribute to creating a moderate access barrier to heterochromatin, allowing minimal protein access to functional regions. Our OI-DIC imaging offers new insight into the live cellular environments.en_US
dc.description.sponsorshipThis work was supported by MEXT and Japan Society for the Promotion of Science (JSPS) grants (Nos. 23115005 and 16H04746, respectively), as well as a Japan Science and Technology Agency (JST) CREST grant (No. JPMJCR15G2). R.I. and T.N. are JSPS Fellows. R.I. was supported by the SOKENDAI Short-Stay Study Abroad Program in fiscal year 2016.en_US
dc.publisherAmerican Society for Cell Biologyen_US
dc.rightsAttribution–Noncommercial–Share Alike 3.0 Unported
dc.titleDensity imaging of heterochromatin in live cells using orientation-independent-DIC microscopyen_US

Files in this item


This item appears in the following Collection(s)

Show simple item record

Attribution–Noncommercial–Share Alike 3.0 Unported
Except where otherwise noted, this item's license is described as Attribution–Noncommercial–Share Alike 3.0 Unported