Improved Experimental Procedures for Achieving Efficient Germ Line Transmission of Nonobese Diabetic (NOD)-Derived Embryonic Stem Cells

The manipulation of a specific gene in NOD mice, the best animal model for insulin-dependent diabetes mellitus (IDDM), must allow for the precise characterization of the functional involvement of its encoded molecule in the pathogenesis of the disease. Although this has been attempted by the cross-breeding of NOD mice with many gene knockout mice originally created on the 129 or C57BL/6 strain background, the interpretation of the resulting phenotype(s) has often been confusing due to the possibility of a known or unknown disease susceptibility locus (e.g., Idd locus) cosegregating with the targeted gene from the diabetes-resistant strain. Therefore, it is important to generate mutant mice on a pure NOD background by using NOD-derived embryonic stem (ES) cells. By using the NOD ES cell line established by Nagafuchi and colleagues in 1999 (FEBSLett., 455, 101–104), the authors reexamined various conditions in the context of cell culture, DNA transfection, and blastocyst injection, and achieved a markedly improved transmission efficiency of these NOD ES cells into the mouse germ line. These modifications will enable gene targeting on a “pure” NOD background with high efficiency, and contribute to clarifying the physiological roles of a variety of genes in the disease course of IDDM

ICTV Virus Taxonomy Profile: Megabirnaviridae

Megabirnaviridae is a family of non-enveloped spherical viruses with dsRNA genomes of two linear segments, each of 7.2-8.9 kbp, comprising 16.1 kbp in total. The genus Megabirnavirus includes the species Rosellinia necatrix megabirnavirus 1, the exemplar isolate of which infects the white root rot fungus (Rosellinia necatrix) to which it confers hypovirulence. Megabirnaviruses are characterized by their bisegmented genome with large 5'-untranslated regions (1.6 kb) upstream of both 5'-proximal coding strand ORFs, and large protrusions on the particle surface. This is a summary of the ICTV Report on the family Megabirnaviridae, which is available at ictv.global/report/megabirnaviridae

韓国語ハングルによる日本語音声表記

日本大学関西学院大学Nihon UniversityKwansei Gakuin University韓国語ハングルによる日本語音声表記というのは，韓国語の表記方法における文字と音声の関係に従って日本語の音声をハングルで表記するものである。たとえば，［ヒツヨー］（必要）は「히츠요오」と表記する。日本語の音声をハングルで表記するときには，一般的に韓国で規範とされる「外来語表記法」が使われている。しかし，この表記法には実際の日本語音声と異なる音声になるものがあったり，長音が表記されなかったりする問題点がある。そこで，そうした問題点を改善した日本語音声表記を提案することにした。韓国語ハングルによる日本語音声表記を提案するために，2つの調査を行った。1つは書き取り調査である。日本語を知らない韓国語母語話者に日本語の音声を聞いてもらい，それをハングルで書き取ってもらう調査である。もう1つは読み上げ調査である。書き取り調査によって絞られたそれぞれの音声表記の候補を読み上げてもらい，日本語らしく発音される可能性の高い表記を確認する調査である。この音声表記の主な特徴は，（a）から（e）のようなものである。（a）母音［ア，イ，ウ，エ，オ］は，それぞれ「아，이，우，에，오」で表す。ただし，［ス］［ツ］［ズ］の母音は［으］を使って，「스」「츠」「즈」のように表記する。（b）カ行とタ行の子音は，激音のハングルを使って表す。カ行は「ㅋ」，タ行の［タ］［テ］［ト］は「ㅌ」，［チ］［ツ］は「ㅊ」で表記する。（c）長音［ー］は，前のモーラの母音に応じて，「아，이，우，으，에，오」のどれかで表す。［ヒツヨー］（必要）は「히츠요오」のように表記する。（d）促音［ッ］は，促音の直前のハングルの終声と促音の直後の濃音の組み合わせで表す。［スッカリ］（すっかり）は「슥까리」のように表記する。（e）撥音［ン］は，ア行・カ行・ハ行・ヤ行・ラ行・［ワ］・ガ行が後続する場合は「ㅇ」，サ行・タ行・ナ行・ザ行・ダ行が後続する場合は「ㄴ」，マ行・バ行・パ行が後続する場合は「ㅁ」で表す。たとえば，［レンアイ］（恋愛）は，「렝아이」のように表記する。Japanese phonetic transcriptions into Korean Hangul involve the transcription of Japanese sounds with Hangul characters according to the relationships between letters and sounds in the Korean writing system. For example, hitsuyō (necessary) is written "히츠요오." There is a standard foreign language transcription system commonly used in South Korea to transcribe Japanese phonetically into Hangul. However, there are some issues with this transcription system, such as the fact that some transcribed sounds are different from actual Japanese sounds and the fact that Japanese long sounds cannot be transcribed. Accordingly, we propose a Japanese phonetic transcription system that addresses these issues.The following two studies were conducted: 1) a dictation study in which native Korean speakers unfamiliar with written Japanese listened to spoken Japanese and noted the words using Hangul; and 2) an oral reading study in which the participants read out each candidate for the phonetic notation method derived from the dictation study, identifying the notation that was most likely to be read the way it sounds in Japanese.The main characteristics of the proposed phonetic notation are detailed below.(a) The vowels [a, i, u, e, o] should be notated as [아, 이, 우, 에, 오], respectively, while the vowels in [su], [tsu], and [zu] should be notated as [스], [츠], and [즈], using [으], respectively.(b) The consonants [k] and [t] are represented by aspirated consonants in Hangul. The consonant [k] should be notated as [ㅋ], while [ta], [te], and [to] should be notated as [ㅌ] and [chi] and [tsu] as [ㅊ].(c) Long vowels are to be notated with one of the following in accordance with the preceding mora vowels [a, i, u, e, o].(d) Moraic obstruents are to be notated by a combination of the final consonant in Hangul immediately before the moraic obstruent and the tense consonant immediately after the moraic obstruent.(e) Moraic nasals should be notated by [ㅇ] if they are followed by the vowels [k], [h], [y], [r], [w], or [g], by [ㄴ] if they are followed by [s], [t], [n], [z], or [d], and by [ㅁ] if they are followed by [m], [b], or [p]

The nuclear receptor LXRα controls the functional specialization of splenic macrophages.

Macrophages are professional phagocytic cells that orchestrate innate immune responses and have considerable phenotypic diversity at different anatomical locations. However, the mechanisms that control the heterogeneity of tissue macrophages are not well characterized. Here we found that the nuclear receptor LXRα was essential for the differentiation of macrophages in the marginal zone (MZ) of the spleen. LXR-deficient mice were defective in the generation of MZ and metallophilic macrophages, which resulted in abnormal responses to blood-borne antigens. Myeloid-specific expression of LXRα or adoptive transfer of wild-type monocytes restored the MZ microenvironment in LXRα-deficient mice. Our results demonstrate that signaling via LXRα in myeloid cells is crucial for the generation of splenic MZ macrophages and identify an unprecedented role for a nuclear receptor in the generation of specialized macrophage subsets

Structural visualization of key steps in nucleosome reorganization by human FACT

Facilitates chromatin transcription (FACT) is a histone chaperone, which accomplishes both nucleosome assembly and disassembly. Our combined cryo-electron microscopy (EM) and native mass spectrometry (MS) studies revealed novel key steps of nucleosome reorganization conducted by a Mid domain and its adjacent acidic AID segment of human FACT. We determined three cryo-EM structures of respective octasomes complexed with the Mid-AID and AID regions, and a hexasome alone. We discovered extensive contacts between a FACT region and histones H2A, H2B, and H3, suggesting that FACT is competent to direct functional replacement of a nucleosomal DNA end by its phosphorylated AID segment (pAID). Mutational assays revealed that the aromatic and phosphorylated residues within pAID are essential for octasome binding. The EM structure of the hexasome, generated by the addition of Mid-pAID or pAID, indicated that the dissociation of H2A-H2B dimer causes significant alteration from the canonical path of the nucleosomal DNA