《自然》（20190627出版）一周論文導讀

翻譯 | 馮唯唯

Nature, 27 June 2019, Volume 570 Issue7762

《自然》2019年6月27日，第570卷7762期

仿生學Bionic Science

Flight of theRoboBee

機器蜂的飛行

作者：Noah T. Jafferis, E. Farrell Helbling, Michael Karpelson和Robert J. Wood

鏈接：

https://www.nature.com/articles/d41586-019-01964-3

摘要：

無論物體的大小如何，飛行一個比空氣重的物體都需要耗費大量的能量，但在非常小的尺度上，這一挑戰會加劇，因為需要集成輕量級組件來提供必要的電子設備和推進力。

這意味著，大多數昆蟲大小的飛行器都是靠外部電源飛行的。

在這一期《自然》雜誌中，Noah Jafferis、Farrell Helbling和同事介紹了一種能夠自由飛行的昆蟲大小的飛行器。

這款飛行器重量僅為90毫克，它有四個翅膀，由兩個壓電驅動器驅動，攜帶一個60毫克的光伏陣列和一個91毫克的信號發生器，這使它的推力效率與同樣大小的昆蟲相當。

Abstract

Flying an object heavier than air is energetically expensive no matter what the size, but this challenge is exacerbated at very small scales because of the need to integrate lightweight components to provide the necessary electronics and propulsion. This means that most insect-size vehicles fly tethered to an off-board power supply. In this week』s issue, Noah Jafferis, Farrell Helbling and their colleagues introduce RoboBee X-Wing, an aerial vehicle the size of an insect that is capable of untethered flight. Weighing just 90 milligrams, RoboBee X-Wing has four wings driven by two piezoelectric actuators and carries a 60-mg photovoltaic array and a 91-mg signal generator, giving it a thrust efficiency matching that of similarly sized insects.

微生物學Microbiology

Mapping human microbiome drug metabolism by gut bacteria and their genes

利用腸道細菌及其基因繪製人類微生物組藥物代謝圖譜

作者：Michael Zimmermann, Maria Zimmermann-Kogadeeva, Rebekka Wegmann和Andrew L. Goodman

鏈接：

https://www.nature.com/articles/s41586-019-1291-3

摘要：

個體對藥物的反應差異很大，由於治療延遲和副作用，可能帶來危險以及花費不菲。

越來越多的證據表明腸道微生物群參與了這種變化性，但其中涉及的分子機制在很大程度上仍不明確。

作者通過測量76種不同分支的人類腸道細菌代謝271種口服藥物的能力，表明許多藥物是由微生物進行化學修飾的。

作者將高通量基因分析與質譜相結合，系統地鑒定了代謝藥物的微生物基因產物。這些微生物編碼酶可以直接且實質性地影響小鼠腸道和全身藥物代謝，並可以根據其基因組含量解釋人類腸道細菌和群落的藥物代謝活動。

這些基因含量和微生物群代謝活動之間的因果關係將微生物群中的人際差異與藥物代謝中的人際差異聯繫起來，對醫學治療和藥物開發具有廣泛的意義。

Abstract

Individuals vary widely in their responses to medicinal drugs, which can be dangerous and expensive owing to treatment delays and adverse effects. Although increasing evidence implicates the gut microbiome in this variability, the molecular mechanisms involved remain largely unknown. Here we show, by measuring the ability of 76 human gut bacteria from diverse clades to metabolize 271 orally administered drugs, that many drugs are chemically modified by micro organisms. We combined high-throughput genetic analyses with mass spectrometry to systematically identify microbial gene products that metabolize drugs. These microbiome-encoded enzymes can directly and substantially affect intestinal and systemic drug metabolism in mice, and can explain the drug-metabolizing activities of human gut bacteria and communities on the basis of their genomic contents. These causal links between the gene content and metabolic activities of the microbiota connect interpersonal variability in microbiomes to interpersonal differences in drug metabolism, which has implications for medical therapy and drug development across multiple disease indications.

生態學Ecology

Global analysis of streamflow response to forest management

森林管理水流響應的全球分析

作者：Jaivime Evaristo和Jeffrey J. McDonnell

鏈接：

https://www.nature.com/articles/s41586-019-1306-0

摘要：

預測水流量對森林管理變化的響應是水資源可持續調節的基礎。然而，對森林覆蓋變化的研究產生的結果卻並不清晰，而且相關結果基本上無法預測。

作者編製了一個全球森林管理研究的全面和空間分布資料庫，以評估控制森林種植和砍伐的水流響應的因素。

為了解釋森林砍伐和種植對水量的影響，作者引入了一個從植被到基岩的模型，其中包括7個關鍵的景觀因素。結果表明，景觀中蓄水量是預測森林徑流響應最重要的因子，而蒸發蒸騰損失是預測森林植被徑流響應最重要的因子。

研究結果影響了全球不同地質和氣候區域的氣候變化減緩計劃的模型參數化，並為水資源的可持續管理提供了實踐依據。

Abstract

Predicting the responses of streamflow to changes in forest management is fundamental to the sustainable regulation of water resources. However, studies of changes in forest cover have yielded unclear and largely unpredictable results. Here we compile a comprehensive and spatially distributed database of forest-management studies worldwide, to assess the factors that control streamflow response to forest planting and removal. We introduce a vegetation-to-bedrock model that includes seven key landscape factors in order to explain the impacts of forest removal and planting on water yield.We show that the amount of water stored in a landscape is the most important factor in predicting streamflow response to forest removal, whereas the loss of water through evaporation and transpiration is the most important factor in predicting streamflow response to forest planting. Our findings affect model parameterizations in climate change mitigation schemes(involving, for example, afforestation or deforestation) in different geologicand climate regions around the world, and inform practices for the sustainable management of water resources.

機器學習Machine learning

Machine learning in electronic-quantum-matter imaging experiments

電子—量子—物質成像實驗中的機器學習

作者：Yi Zhang, A. Mesaros, K. Fujita, S. D. Edkins, M. H. Hamidian, Eun-Ah Kim, etc.

鏈接：

https://www.nature.com/articles/s41586-019-1319-8

摘要：

數個世紀以來，科學發現的過程建立在人類對自然現象的系統觀察和分析基礎上。然而，今天自動化儀器和大規模數據採集正在生成如此龐大和複雜的數據集，這是對傳統科學方法的挑戰。

當前迫切需要完全不同的科學方法，而機器學習（ML）在材料科學等研究領域顯示出巨大的前景。

鑒於ML在分析表示電子量子物質的合成數據（EQM）方面的成功性，下一個挑戰是將這種方法應用於實驗數據，例如，從EQM的原子尺度可視化中獲得的複雜電子結構圖像陣列。

作者報告了一套人工神經網路（ANNs）的開發和訓練，該網路旨在識別隱藏在諸如EQM圖像陣列中不同類型的順序。這些ANNs被用於分析從摻雜氧化銅Mott絕緣子實驗中導出的EQM圖像陣列的存檔。

在這些嘈雜而複雜的數據中，ANNs發現了「一種網格匹配的、四單元細胞周期的、平移對稱破壞」的EQM狀態的存在。

此外，ANNs確定了這種狀態是單向的，揭示了一種一致的向列相EQM狀態。電子液晶的強耦合理論與這些觀測結果是一致的。

Abstract

For centuries, the scientific discovery process has been based on systematic human observation and analysis of natural phenomena. Today, however, automated instrumentation and large-scale data acquisition are generating datasets of such large volume and complexity as to defy conventional scientific methodology. Radically different scientific approaches are needed, and machine learning (ML) shows great promise for research fields such as materials science. Given the success of ML in the analysis of synthetic data representing electronic quantum matter (EQM), the next challenge is to apply this approach to experimental data—for example, to the arrays of complex electronic-structure images obtained from atomic-scale visualization of EQM. Here we report the development and training of a suite of artificial neural networks (ANNs) designed to recognize different types of order hidden in such EQM image arrays. These ANNs are used to analyse an archive of experimentally derived EQM image arrays from carrier-doped copper oxide Mott insulators. In these noisy and complex data, the ANNs discover the existence of a lattice-commensurate, four-unit-cell periodic, translational-symmetry-breaking EQM state. Further, the ANNs determine that this state is unidirectional, revealing a coincident nematic EQM state. Strong-coupling theories of electronic liquid crystals are consistent with these observations.

遺傳學Genetics

Genetic analyses of diverse populations improves discovery for complex traits

不同種群遺傳分析提高對複雜性狀的發現

作者：Genevieve L. Wojcik, Mariaelisa Graff, Christopher S. Carlso, etc.

鏈接：

https://www.nature.com/articles/s41586-019-1310-4

摘要：

全基因組關聯研究（GWAS）為了解複雜性狀的生物特徵、藥物開發和臨床規範奠定了基礎。然而，目前大多數發現都是基於歐洲血統的數據。作者展示了大規模基因組研究中多元、多種族參與者的價值。

「人口結構」項目利用基因組學和流行病學（PAGE）研究，對49839名非歐洲個體進行了26種臨床和行為表型的GWAS。

利用專為分析多種族和混合人群而設計的策略，作者描述了一個分析不同人群的框架，在已知的位點識別27個新位點和38個次級信號，並複製了1444個與這些特徵相關聯的GWAS目錄。

研究數據表明，對於已發表的GWAS關聯，跨祖先的效應大小異質性是有證據的，使用不同的群組和對臨床意義的洞察進行精細映射，將帶來巨大的好處。

在美國，少數族裔人群承受著更高的慢性病負擔，在遺傳研究中缺乏多樣性人群的代表性，將導致那些疾病負擔最重的人群在精準醫療的方面出現不公平。作者強烈主張在不同人群中繼續開展大規模的全基因組努力，以最大限度地做出基因發現並減少健康差異。

Abstract

Genome-wide association studies (GWAS) have laid the foundation for investigations into the biology of complex traits,drug development and clinical guide lines. However, the majority of discovery efforts are based on data from populations of European ancestry. Here we demonstrate the value of diverse, multi-ethnic participants in large-scale genomic studies. The Population Architecture using Genomics and Epidemiology (PAGE) study conducted a GWAS of 26 clinical and behavioural phenotypes in 49,839 non-European individuals. Using strategies tailored for analysis of multi-ethnic and admixed populations, we describe a framework for analysing diverse populations, identify 27 novel loci and 38 secondary signals at knownloci, as well as replicate 1,444 GWAS catalogue associations across these traits. Our data show evidence of effect-size heterogeneity across ancestriesfor published GWAS associations, substantial benefits for fine-mapping using diverse cohorts and insights into clinical implications. In the United States—where minority populations have a disproportionately higher burden of chronic conditions 13—the lack of representation of diverse populations in genetic research will result in in equitable access to precision medicine for those with the highest burden of disease. We strongly advocate for continued, large genome-wide efforts in diverse populations to maximize genetic discovery and reduce health disparities.

生物學Biology

Pluripotency and the origin of animal multicellularity

多能性與動物多細胞性的起源

作者：Shunsuke Sogabe, William L. Hatleberg, Bernard M. Degnan, etc.

鏈接：

https://www.nature.com/articles/s41586-019-1290-4

摘要：

關於動物起源的一種普遍存在但很少被證實的假說是，它們是從一個單細胞祖先進化而來的，其頂端纖毛周圍有一個微絨毛項圈，在結構上類似於現代海綿動物領細胞和領鞭毛蟲。

作者通過比較三種主要海綿細胞類型（領細胞、多能間充質領細胞和扁上皮細胞）的轉錄組、命運和行為，來檢驗這一動物起源的觀點。

出乎意料的是，作者發現領細胞的轉錄組與領鞭毛蟲的轉錄組最不相似，而且其轉錄組中含有大量動物或海綿動物獨有的基因。

相比之下，多能間充質領細胞，包括一個群居的領鞭毛蟲，會上調控制細胞增殖和基因表達的基因，正如在其他後生動物幹細胞中，以及在兩個單細胞全蟲的增殖階段一樣。

這些分析反駁了海綿領細胞和領鞭毛蟲的同源性，以及認為最早的多細胞動物是簡單的細胞球，其分化能力有限的觀點。相反，研究結果與第一個動物細胞能夠以類似於現代轉分化和幹細胞的方式在多種狀態之間轉換相一致。

Abstract

A widely held—but rarely tested—hypothesis for the origin of animals is that they evolved from a unicellular ancestor, with an apical cilium surrounded by a microvillar collar, that structurally resembled modern sponge choanocytes and choanoflagellates. Here we test this view of animal origins by comparing the transcriptomes, fates and behaviours of the three primary sponge cell types—choanocytes, pluripotent mesenchymalar chaeocytes and epithelial pinacocytes—with choanoflagellates and other unicellular holozoans. Unexpectedly, we find that the transcriptome of sponge choanocytes is the least similar to the transcriptomes of choanoflagellates and is significantly enriched in genes unique to either animals or sponges alone. By contrast, pluripotent archaeocytes upregulate genes that control cell proliferation and gene expression, as in other metazoan stem cells and in the proliferating stages of two unicellular holozoans, including a colonial choanoflagellate. Together, these analyses argue against homology of sponge choanocytes and choanoflagellates, and the view that the first multicellular animals were simple balls of cells with limited capacity to differentiate. Instead, our results are consistent with the first animal cell being able to transition between multiple states in a manner similar to modern transdifferentiating and stemcells.

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