助成審査における偏見の問題を科学的に調査する、米国立衛生研究所（NIH）の姿勢は評価すべきだ。
Finding the root p.231
The NIH is right to investigate whether bias makes grant awards unfair.
doi: 10.1038/512231b
Volume 512 Number 7514
今週のハイライト
Cover Story: 早くから始まっていた適応：最初期ステム哺乳類での食餌の特殊化
分子生物学: リボソームフレームシフトによる免疫応答の微調整
構造生物学: GABAA受容体の構造
構造生物学: セロトニン5-HT3受容体の構造
物理: 二原子分子を三次元的に閉じ込める
地球: 2014年イキケ地震の検証
古人類学: ネアンデルタール人の緩やかな排除
生物地球化学: ウィランズ氷底湖に生息する豊富な微生物
細胞: 胚の造血幹細胞
目次
Editorials
米科学界は、無人飛行機の研究利用が不当に妨げられないよう、政府当局に対し声を上げるべきだ。
What goes up p.231
Federal restrictions on the use of drones by US researchers threaten an increasingly productive tool. The scientific community must speak out while there is a chance to change matters.
doi: 10.1038/512231a
News
米連邦航空局（FAA）が、私立大学での研究用無人飛行機の利用に「ノー」を。
US drone research hits regulatory turbulence p.239
Federal rules ground scientists using remotely piloted aircraft at private universities.
doi: 10.1038/512239a
気候変動と開発によって、チベット高原の脆弱な生態系が危機に。
Double threat for Tibet p.240
Climate change and human development are jeopardizing the plateau’s fragile environment.
doi: 10.1038/512240a
放射性炭素年代測定法の技術改良により、ネアンデルタール人の消滅時期など先史時代の歴史が書き換えへ。
Bone technique redrafts prehistory p.242
Carbon-dating improvements show that Neanderthals disappeared from Europe much earlier than thought.
doi: 10.1038/512242a
NIHが、助成審査における人種的不公平の根絶に向け、取り組みを。
NIH to probe racial disparity in grant awards p.243
US agency will assess whether grant reviewers are biased against minority applicants.
doi: 10.1038/512243a
News Features
極地域の科学：南極の秘密の湖
Lakes under the ice: Antarctica's secret garden p.244
南極の分厚い氷の下、800 mの所にある隠れた湖から採取された試料には、多数の微生物と、未知の広大な生態系の手がかりが含まれている。
doi: 10.1038/512244a
News & Views
生物地球化学：氷の下の微生物は岩石を食べる
Biogeochemistry: Microbes eat rock under ice p.256
南極氷床下の深い所にある氷底湖に生息している微生物についての初めての報告から、複雑な双方向性の代謝過程の一部が明らかになった。こうした代謝過程がこの微生物群集を維持しているのである。
doi: 10.1038/512256a
発生生物学：血液細胞を作るには筋肉が必要
Developmental biology: It takes muscle to make blood cells p.257
造血幹細胞の少なくとも一部は、背側大動脈と呼ばれる胚の血管に由来する。血管に隣接する体節と呼ばれる組織がこの過程に細胞やシグナルを提供していることが分かってきた。
doi: 10.1038/nature13740
地球科学：イキケ地震の警戒標識
Earth science: Warning signs of the Iquique earthquake p.258
2014年にチリ沖で起こった地震は、大地震が予測されていた地域で発生した。今回、2つの研究によって、大地震に先立って、関連するプレート境界断層で数か月にわたる前震とスロースリップが起こっていたことが分かった。
doi: 10.1038/nature13655
古人類学：最後のネアンデルタール人が居た時代
Palaeoanthropology: The time of the last Neanderthals p.260
改良された放射性炭素年代測定技術を使って、ロシアからスペインに至る考古遺跡から出土した標本が再検討され、ネアンデルタール人がヨーロッパから最終的に消滅した時期が再決定された。
doi: 10.1038/512260a
分子物理学：単純な方法で捕捉された複雑な分子
Molecular physics: Complexity trapped by simplicity p.261
磁気光学トラップと呼ばれる装置は、原子の冷却や閉じ込めにずっと使われてきたが、分子についてはこれまで適用されたことがなかった。分子の閉じ込めが今回新たに達成されたことで、極低温分子の物理的性質に関する多数の研究やその応用が可能となりそうだ。
doi: 10.1038/512261a
個体群史：東南アジアの人種のるつぼ
Population history: Human melting pots in southeast Asia p.262
複数の人種が混じり合ったヒト個体群の解析が新しい遺伝学的方法を用いて行われ、オーストロネシア語を話す人々の歴史的移動と混合に関して示されている学術的な証拠に対して、さらなる裏付けが得られた。
doi: 10.1038/512262a
Articles
分子生物学：CCR5 mRNAのリボソームフレームシフトはmiRNAとNMD経路によって調節される
Ribosomal frameshifting in the CCR5 mRNA is regulated by miRNAs and the NMD pathway p.265
Programmed −1 ribosomal frameshifting (−1 PRF) is a process by which a signal in a messenger RNA causes a translating ribosome to shift by one nucleotide, thus changing the reading frame; here −1 PRF in the mRNA for the co-receptor for HIV-1, CCR5, is stimulated by two microRNAs and leads to degradation of the transcript by nonsense-mediated decay and at least one other decay pathway.
doi: 10.1038/nature13429
構造生物学：ヒトGABAA受容体の結晶構造
Crystal structure of a human GABAA receptor p.270
GABAA receptors are the principal mediators of rapid inhibitor synaptic transmission in the brain, and a decline in GABAA signalling leads to diseases including epilepsy, insomnia, anxiety and autism; here, the first X-ray crystal structure of a human GABAA receptor, the human β3 homopentamer, reveals structural features unique for this receptor class and uncovers the locations of key disease-causing mutations.
doi: 10.1038/nature13293
構造生物学：マウスのセロトニン5-HT3受容体のX線構造
X-ray structure of the mouse serotonin 5-HT3 receptor p.276
The first X-ray crystal structure of the mouse serotonin 5-HT3 receptor, a pentameric ligand-gated ion channel, is similar to those of other Cys-loop receptors — though here electron density for part of the cytoplasmic domain, which is important for trafficking, synaptic localization, and modulation by cytoplasmic proteins, but not visible in previous structures, is also described.
doi: 10.1038/nature13552
Letters
宇宙：赤色超巨星を取り巻く光イオン化で閉じ込められた殻により相互作用する超新星
Interacting supernovae from photoionization-confined shells around red supergiant stars p.282
A model in which the stellar wind of the fast-moving red supergiant Betelgeuse is photoionized by radiation from external sources can explain the dense, almost static shell recently discovered around the star, and predicts both that debris from Betelgeuse’s eventual supernova explosion will violently collide with the shell and that other red supergiants should have similar, but much more massive, shells.
doi: 10.1038/nature13522
物理：二原子分子の磁気光学トラッピング
Magneto-optical trapping of a diatomic molecule p.286
Magneto-optical trapping is the standard method for laser cooling and confinement of atomic gases but now this technique has been demonstrated for the diatomic molecule strontium monofluoride, leading to the lowest temperature yet achieved by cooling a molecular gas.
doi: 10.1038/nature13634
気候：氷床の変化によって制御される氷期の急激な気候変動
Abrupt glacial climate shifts controlled by ice sheet changes p.290
The volume of the Northern Hemisphere ice sheet controlled abrupt millennial-scale climate changes during the last glacial.
doi: 10.1038/nature13592
地球：2014年イキケ地震後も残るチリの巨大地震発生の可能性
Continuing megathrust earthquake potential in Chile after the 2014 Iquique earthquake p.295
The 2014 Iquique event was not the earthquake that had been expected to fill the regional seismic gap; given that significant sections of the northern Chile subduction zone have not ruptured in almost 150 years, it is likely that future megathrust earthquakes will occur south and potentially north of the 2014 Iquique sequence.
doi: 10.1038/nature13677
地球：2014年イキケ地震の始まりを支配したプレート境界の緩やかな解放
Gradual unlocking of plate boundary controlled initiation of the 2014 Iquique earthquake p.299
A long foreshock series unlocked the South American plate boundary until eventually initiating the M 8.1 Iquique, Chile, earthquake.
doi: 10.1038/nature13681
進化：最初期のステム哺乳類の摂餌生態に見られる食餌の特殊化と多様性
Dietary specializations and diversity in feeding ecology of the earliest stem mammals p.303
Differences in function and dietary ecology between Morganucodon and Kuehneotherium show that lineage splitting during the earliest stages of mammalian evolution was associated with ecomorphological specialization and niche partitioning.
doi: 10.1038/nature13622
古人類学：ネアンデルタール人消滅の時期と時空間的パターン化
The timing and spatiotemporal patterning of Neanderthal disappearance p.306
Accelerator mass spectrometry radiocarbon dating is used to construct a chronology of Neanderthal disappearance, showing that Neanderthals overlapped with anatomically modern humans for between about 2,000 and 5,000 years.
doi: 10.1038/nature13621
生物地球化学：西南極氷床下に存在する微生物生態系
A microbial ecosystem beneath the West Antarctic ice sheet p.310
There has been active debate over microbial life in Antarctic subglacial lakes owing to a paucity of direct observations from beneath the ice sheet and concerns about contamination in the samples that do exist; here the authors present the first geomicrobiological description of pristine water and surficial sediments from Subglacial Lake Whillans, and show that the lake water contains a diverse microbial community, many members of which are closely related to chemolithoautotrophic bacteria and archaea.
doi: 10.1038/nature13667
細胞：meox1によって制御される体節由来内皮細胞による造血幹細胞の誘導
Haematopoietic stem cell induction by somite-derived endothelial cells controlled by meox1 p.314
A new somite compartment, called the endotome, that contributes to the formation of the embryonic dorsal aorta by providing endothelial progenitors is identified here; endotome-derived endothelial progenitors, whose formation is regulated by the activity of the meox1 gene, induce haematopoietic stem cell formation upon colonization of the nascent dorsal aorta.
doi: 10.1038/nature13678
細胞：Jam1aとJam2aの相互作用がNotchシグナル伝達を介した造血幹細胞の運命を調節する
Jam1a–Jam2a interactions regulate haematopoietic stem cell fate through Notch signalling p.319
Notch signalling has a key role in the generation of haematopoietic stem cells (HSCs) during vertebrate development; here two adhesion molecules, Jam1a and Jam2a, are shown to be essential for the contact between precursors of HSCs and the somite during embryonic migration, and the Jam1a–Jam2a interaction is shown to be needed to transmit the Notch signal and produce HSCs.
doi: 10.1038/nature13623
がん：変異型IDH1を標的とするワクチンは抗腫瘍免疫を誘導する
A vaccine targeting mutant IDH1 induces antitumour immunity p.324
The mutant IDH1 protein, which is expressed in a large fraction of human gliomas, is shown to be immunogenic; mutant-specific immune responses can be detected in patients with IDH1 mutated gliomas and generated in mice and are shown to treat established IDH1 mutant tumours in a syngeneic MHC humanized mouse model in a CD4 T-cell-dependent manner.
doi: 10.1038/nature13387
分子生物学：翻訳の−1フレームシフトの動的経路
Dynamic pathways of −1 translational frameshifting p.328
To investigate the mechanism of frameshifting during messenger RNA translation, a technique was developed to monitor translation of single molecules in real time using Förster resonance energy transfer (FRET); ribosomes were revealed to pause tenfold longer than usual during elongation at the frameshifting sites.
doi: 10.1038/nature13428
構造生物学：アポ状態のGluClのX線構造から明らかになったCysループ型受容体の開閉制御機構
X-ray structures of GluCl in apo states reveal a gating mechanism of Cys-loop receptors p.333
This study solved structures of the glutamate-gated chloride channel (GluCl), a Cys-loop receptor from C. elegant, in an apo, closed state and in a lipid-bound state — comparison of these structures with a previously published structure of GluCl in an ivermectin-bound state reveals what conformational changes probably occur as this membrane protein transitions from the closed/resting state towards an open/activated state.
doi: 10.1038/nature13669
