《科學》（20190329出版）一周論文導讀

翻譯 | 唐一塵

Science, 29 MARCH 2019, VOL 363, ISSUE 6434

《科學》2019年3月29日，第6434期363卷

微生物Microbiology

Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity

兩棲真菌引起災難性、持續的生物多樣性喪失

作者：Ben C. Scheele、Frank Pasmans、Lee F. Skerratt，et al

鏈接：

http://science.sciencemag.org/content/363/6434/1459

摘要：

壺菌病是由蛙壺菌（Bd）引起的，這種兩棲類中高度烈性的真菌性疾病，它與過去50年中全球超過500種兩棲動物的數目衰減有關（其中包括90種被推測已經滅絕的兩棲動物），其傳播機制可能是通過全球性的動物交易。但由於適用數據缺乏，科學家只能猜測由Bd對全球兩棲類種群所造成的傷害規模。

本論文首次對該病原體對全球兩棲類動物所造成的死亡進行了計數，結果發現，兩棲類動物的該致病原大流行代表了有記錄的可歸因於該病的生物多元性最大規模的喪失。

研究人員使用了一個全球綜合性的與壺菌病相關的兩棲類衰減的數據集來重建該致死性疾病的歷史，發現Bd屬最具破壞性的入侵菌種。該菌造成至少501種兩棲類動物的種群數衰減，其中124種的丰度降幅大於90%。

Abstract

Anthropogenic trade and development have broken down dispersal barriers, facilitating the spread of diseases that threaten Earth』s biodiversity. We present a global, quantitative assessment of the amphibian chytridiomycosis panzootic, one of the most impactful examples of disease spread, and demonstrate its role in the decline of at least 501 amphibian species over the past half-century, including 90 presumed extinctions. The effects of chytridiomycosis have been greatest in large-bodied, range-restricted anurans in wet climates in the Americas and Australia. Declines peaked in the 1980s, and only 12% of declined species show signs of recovery, whereas 39% are experiencing ongoing decline. There is risk of further chytridiomycosis outbreaks in new areas. The chytridiomycosis panzootic represents the greatest recorded loss of biodiversity attributable to adisease.

Bacteriophage trigger antiviral immunity and prevent clearance of bacterial infection

噬菌體觸發抗病毒免疫及阻止細菌感染的清除

作者：Johanna M. Sweere、Jonas D. Van Belleghem、Heather Ishak、Michelle S. Bach，et al

鏈接：

http://science.sciencemag.org/content/363/6434/eaat9691

摘要：

噬菌體在細菌感染部位大量存在，但它們對哺乳動物宿主的影響尚不清楚。人們已經確定了綠膿桿菌（Pa)產生的絲狀噬菌體在抑制細菌感染免疫方面的致病作用。

該噬菌體促進小鼠Pa傷口感染，並與人類慢性Pa傷口感染有關。

小鼠和人類白細胞吞噬該噬菌體，並且這種單鏈DNA病毒的內化導致噬菌體RNA的產生。這會觸發乾擾素生產、抑制腫瘤壞死因子和壓制吞噬作用。相反，小鼠對該噬菌體免疫可預防Pa傷口感染。

研究人員表示，這顯示噬菌體觸發了非適應性先天病毒模式識別反應，阻止了細菌的清除。因此，接種噬菌體病毒粒子疫苗是一種潛在的治療策略。

Abstract

Bacteriophage are abundant at sites of bacterial infection, but their effects on mammalian hosts are unclear. We have identified pathogenic roles for filamentous Pf bacteriophage produced by Pseudomonas aeruginosa (Pa) in suppression of immunity against bacterial infection. Pf promotePawound infection in mice and are associated with chronic humanPawound infections. Murine and human leukocytes endocytose Pf, and internalization of this single-stranded DNA virus results in phage RNA production. This triggers Toll-like receptor 3 (TLR3)– and TIR domain–containing adapter-inducing interferon-β (TRIF)–dependent type I interferon production, inhibition of tumornecrosis factor (TNF), and the suppression of phagocytosis. Conversely, immunization of mice against Pf prevents Pa wound infection. Thus, Pf triggers maladaptive innate viral pattern-recognition responses, which impair bacterial clearance. Vaccination against phage virions represents a potential strategy to prevent bacterial infection.

生物Biology

Optogenetic manipulation of stomatal kinetics improves carbon assimilation, water use, and growth

氣孔動力學的光遺傳學操作改善了植物碳吸收、水分利用和生長

作者：M. Papanatsiou、Y. Wang、J. M. Christie、M. R. Blatt，et al

鏈接：

http://science.sciencemag.org/content/363/6434/1456

摘要：

氣孔是分布在植物葉子表面的細孔，它能通過對環境作出開與關的反應，調節用於光合作用的二氧化碳的攝取和水分蒸發。然而，這些雙重作用常常是互為對立而且運作是以損及對方為代價的。

儘管氣孔開放或能讓植物吸收大量的碳進行光合作用，但它會以失水增加為代價。而且，在自然光波動的環境中，氣孔開放或關閉的時間會比需要的時間更長。

研究人員應用光遺傳學工具BLINK1（藍光誘導的K+通道-1）在芥子植物擬南芥氣孔中構建一種特別的離子通道。該離子通道可通過與藍光接觸而激活，它會導致氣孔更快地開放或關閉。

該氣孔反應速度的加快能在不以二氧化碳攝取為代價的情況下提高擬南芥的用水功效。

Abstract

Stomata serve dual and often conflicting roles, facilitating carbon dioxide influx into the plant leaf for photosynthesis and restricting water efflux via transpiration. Strategies for reducing transpiration without incurring a cost for photosynthesis must circumvent this inherent coupling ofcarbon dioxide and water vapor diffusion. We expressed the synthetic, light-gated K+ channel BLINK1 in guard cells surrounding stomatal pores in Arabidopsisto enhance the solute fluxes that drive stomatal aperture. BLINK1 introduced a K+ conductance and accelerated both stomatal opening under light exposure and closing after irradiation. Integrated over the growth period, BLINK1 drovea 2.2-fold increase in biomass in fluctuating light without cost in water useby the plant. Thus, we demonstrate the potential of enhancing stomatal kinetics to improve water use efficiency without penalty in carbon fixation.

Human impact erodes chimpanzee behavioral diversity

人類的影響侵蝕了黑猩猩的行為多樣性

作者：Hjalmar S. Kühl、Christophe Boesch、Lars Kulik、Fabian Haas，et al

鏈接：

http://science.sciencemag.org/content/363/6434/1453

摘要：

在非人類物種中，黑猩猩具有大量的行為和文化特徵。「干擾假說」預測，人類影響會耗盡其資源，破壞黑猩猩行為和文化傳播所必需的社會學習過程。

本研究使用了144個黑猩猩群落的數據集，其中包含了31種行為的信息，結果表明，與低影響區域相比，居住在受人類影響較大區域的黑猩猩的所有行為發生的平均概率降低了88%。

研究人員表示，無論行為的分組或分類如何，這種行為多樣性的喪失都是顯而易見的。因此，人類影響可能不僅與種群的減少和遺傳多樣性有關，還會影響動物的行為。

該研究結果支持這樣一種觀點，即「具有文化意義的單元」應該納入野生動物保護。

Abstract

Chimpanzees possess a large number of behavioral and cultural traits among nonhuman species. The 「disturbance hypothesis」 predicts that human impact depletes resources and disrupts social learning processes necessary forbehavioral and cultural transmission. We used a dataset of 144 chimpanzee communities, with information on 31 behaviors, to show that chimpanzees inhabiting areas with high human impact have a mean probability of occurrence reduced by 88%, across all behaviors, compared to low-impact areas. This behavioral diversity loss was evident irrespective of the grouping or categorization of behaviors. Therefore, human impact may not only be associated with the loss of populations and genetic diversity, but also affects how animals behave. Our results support the view that 「culturally significant units」 should be integrated into wildlife conservation.

材料/生態

Materials/Ecology

Natural, incidental, and engineered nanomaterials and their impacts on the Earth system

天然、偶然和工程納米材料及其對地球系統的影響

作者：Michael F. Hochella Jr.、David W. Mogk、James Ranville、Irving C. Allen，et al

鏈接：

http://science.sciencemag.org/content/363/6434/eaau8299

摘要：

納米材料是地球系統過去、現在和未來特性和行為的關鍵組成部分。自從地球起源以來，它們就大量存在。

生命，從最早的細胞到現代人類，都是在與自然產生的納米材料密切相關的過程中進化而來的。隨著人類工業化，這種協同作用開始發生重大轉變。

特別是自工業革命以來，偶然產生的納米材料（人類活動無意中產生的）一直在不斷地生產和分布在世界各地。在某些領域，它們的數量已經可以與自然產生的納米材料相媲美。

在過去的半個世紀里，相對於其他兩種納米材料，工程納米材料的產量非常小，但影響較大，使它們成為地球的重要組成部分。所有的納米材料，無論其來源如何，都具有獨特的化學和物理性質。

研究人員表示，隨著實驗、計算、分析和現場方法的重大進展，人們有可能更好地評估和理解地球系統中納米材料的所有類型和起源。現在還可以在地方、區域和全球範圍內確定它們對環境和人類健康的直接和長期影響。

Abstract

Nanomaterials are critical components in the Earth system』spast, present, and future characteristics and behavior. They have been present since Earth』s origin in great abundance. Life, from the earliest cells to modern humans, has evolved in intimate association with naturally occurring nanomaterials. This synergy began to shift considerably with human industrialization. Particularly since the Industrial Revolution some two-and-a-half centuries ago, incidental nanomaterials (produced unintentionally by human activity) have been continuously produced and distributed worldwide. In some areas, they now rivalthe amount of naturally occurring nanomaterials. In the past half-century, engineered nanomaterials have been produced in very small amounts relative to the other two types of nanomaterials, but still in large enough quantities to make them a consequential component of the planet. All nanomaterials, regardless of their origin, have distinct chemical and physical properties throughout their size range, clearly setting them apart from their macroscopic equivalents and necessitating careful study. Following major advances inexperimental, computational, analytical, and field approaches, it is becoming possible to better assess and understand all types and origins of nanomaterials in the Earth system. It is also now possible to frame their immediate and long-term impact on environmental and human health at local, regional, and global scales.

Cross-boundary human impacts compromise the Serengeti-Mara ecosystem

周邊人類影響破壞了塞倫蓋蒂—馬拉生態系統

作者：Michiel P. Veldhuis、Mark E. Ritchie、Joseph O. Ogutu，et al

鏈接：

http://science.sciencemag.org/content/363/6434/1424

摘要：

儘管環繞保護地已成為一種用於保護脆弱的生物多樣性和生態系統的重要而且常用的工具，但它們中有近1/3受到人類活動的強烈壓力，尤其是來自沿著其邊界地區人口快速增長及活動的壓力。

然而，環繞保護地保護區策略的永續性尚屬未知，尤其當考慮到對這些邊際地區的影響並不十分清楚。

本研究研究利用了對東非塞倫蓋蒂—馬拉生態系統長達40年的觀察數據。

這裡是地球上最大的環繞保護地之一，它也是超過200萬個遷徙性大型食草動物的家園。隨著周圍地區朝著農業和田園土地使用的轉變，那裡的人口在過去20年中持續增長。

研究發現，人的這類活動產生將野生動物「擠壓」至該4萬平方公里環繞保護地核心，對生態學功能和該生態系統完整性產生了很大的衝擊。這些結果還顯示了野生動物遷徙和吃草方式發生地區規模的改變，對極端乾旱的易受傷害性增加。

Abstract

Protected areas provide major benefits for humans in the form of ecosystem services, but landscape degradation by human activity at their edgesmay compromise their ecological functioning. Using multiple lines of evidence from 40 years of research in the Serengeti-Mara ecosystem, we find that suchedge degradation has effectively 「squeezed」 wildlife into the core protected area and has altered the ecosystem』s dynamics even within this 40,000-square-kilometer ecosystem. This spatial cascade reduced resilience in the core and was mediated by the movement of grazers, which reduced grass fueland fires, weakened the capacity of soils to sequester nutrients and carbon, and decreased the responsiveness of primary production to rainfall. Similar effectsin other protected ecosystems worldwide may require rethinking of natural resource management outside protected areas.

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