《科学》（20190329出版）一周论文导读

Science, 29 MARCH 2019, VOL 363, ISSUE 6434

《科学》2019年3月29日，第6434期363卷

Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity

两栖真菌引起灾难性、持续的生物多样性丧失

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

▲ 链接：

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

▲ 摘要：

壶菌病是由蛙壶菌（Bd）引起的，这种两栖类中高度烈性的真菌性疾病，它与过去50年中全球超过500种两栖动物的数目衰减有关（其中包括90种被推测已经灭绝的两栖动物），其传播机制可能是通过全球性的动物交易。但由于适用数据缺乏，科学家只能猜测由Bd对全球两栖类种群所造成的伤害规模。

本论文首次对该病原体对全球两栖类动物所造成的死亡进行了计数，结果发现，两栖类动物的该致病原大流行代表了有记录的可归因于该病的生物多元性最大规模的丧失。

研究人员使用了一个全球综合性的与壶菌病相关的两栖类衰减的数据集来重建该致死性疾病的历史，发现Bd属最具破坏性的入侵菌种。该菌造成至少501种两栖类动物的种群数衰减，其中124种的丰度降幅大于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

噬菌体触发抗病毒免疫及阻止细菌感染的清除

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

▲ 链接：

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

▲ 摘要：

噬菌体在细菌感染部位大量存在，但它们对哺乳动物宿主的影响尚不清楚。人们已经确定了绿脓杆菌（Pa)产生的丝状噬菌体在抑制细菌感染免疫方面的致病作用。

该噬菌体促进小鼠Pa伤口感染，并与人类慢性Pa伤口感染有关。

小鼠和人类白细胞吞噬该噬菌体，并且这种单链DNA病毒的内化导致噬菌体RNA的产生。这会触发干扰素生产、抑制肿瘤坏死因子和压制吞噬作用。相反，小鼠对该噬菌体免疫可预防Pa伤口感染。

研究人员表示，这显示噬菌体触发了非适应性先天病毒模式识别反应，阻止了细菌的清除。因此，接种噬菌体病毒粒子疫苗是一种潜在的治疗策略。

▲ 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 promote Pa wound infection in mice and are associated with chronic human Pa wound 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.

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

气孔动力学的光遗传学操作改善了植物碳吸收、水分利用和生长

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

▲ 链接：

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

▲ 摘要：

气孔是分布在植物叶子表面的细孔，它能通过对环境作出开与关的反应，调节用于光合作用的二氧化碳的摄取和水分蒸发。然而，这些双重作用常常是互为对立而且运作是以损及对方为代价的。

尽管气孔开放或能让植物吸收大量的碳进行光合作用，但它会以失水增加为代价。而且，在自然光波动的环境中，气孔开放或关闭的时间会比需要的时间更长。

研究人员应用光遗传学工具BLINK1（蓝光诱导的K+通道-1）在芥子植物拟南芥气孔中构建一种特别的离子通道。该离子通道可通过与蓝光接触而激活，它会导致气孔更快地开放或关闭。

该气孔反应速度的加快能在不以二氧化碳摄取为代价的情况下提高拟南芥的用水功效。

▲ 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 Arabidopsis to 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

人类的影响侵蚀了黑猩猩的行为多样性

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

▲ 链接：

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

▲ 摘要：

在非人类物种中，黑猩猩具有大量的行为和文化特征。“干扰假说”预测，人类影响会耗尽其资源，破坏黑猩猩行为和文化传播所必需的社会学习过程。

本研究使用了144个黑猩猩群落的数据集，其中包含了31种行为的信息，结果表明，与低影响区域相比，居住在受人类影响较大区域的黑猩猩的所有行为发生的平均概率降低了88%。

研究人员表示，无论行为的分组或分类如何，这种行为多样性的丧失都是显而易见的。因此，人类影响可能不仅与种群的减少和遗传多样性有关，还会影响动物的行为。

该研究结果支持这样一种观点，即“具有文化意义的单元”应该纳入野生动物保护。

▲ 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.

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

天然、偶然和工程纳米材料及其对地球系统的影响

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

▲ 链接：

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

▲ 摘要：

纳米材料是地球系统过去、现在和未来特性和行为的关键组成部分。自从地球起源以来，它们就大量存在。

生命，从最早的细胞到现代人类，都是在与自然产生的纳米材料密切相关的过程中进化而来的。随着人类工业化，这种协同作用开始发生重大转变。

特别是自工业革命以来，偶然产生的纳米材料（人类活动无意中产生的）一直在不断地生产和分布在世界各地。在某些领域，它们的数量已经可以与自然产生的纳米材料相媲美。

在过去的半个世纪里，相对于其他两种纳米材料，工程纳米材料的产量非常小，但影响较大，使它们成为地球的重要组成部分。所有的纳米材料，无论其来源如何，都具有独特的化学和物理性质。

研究人员表示，随着实验、计算、分析和现场方法的重大进展，人们有可能更好地评估和理解地球系统中纳米材料的所有类型和起源。现在还可以在地方、区域和全球范围内确定它们对环境和人类健康的直接和长期影响。

▲ 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

周边人类影响破坏了塞伦盖蒂—马拉生态系统

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

▲ 链接：

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

▲ 摘要：

尽管环绕保护地已成为一种用于保护脆弱的生物多样性和生态系统的重要而且常用的工具，但它们中有近1/3受到人类活动的强烈压力，尤其是来自沿着其边界地区人口快速增长及活动的压力。

然而，环绕保护地保护区策略的永续性尚属未知，尤其当考虑到对这些边际地区的影响并不十分清楚。

本研究研究利用了对东非塞伦盖蒂—马拉生态系统长达40年的观察数据。

这里是地球上最大的环绕保护地之一，它也是超过200万个迁徙性大型食草动物的家园。随着周围地区朝着农业和田园土地使用的转变，那里的人口在过去20年中持续增长。

研究发现，人的这类活动产生将野生动物“挤压”至该4万平方公里环绕保护地核心，对生态学功能和该生态系统完整性产生了很大的冲击。这些结果还显示了野生动物迁徙和吃草方式发生地区规模的改变，对极端干旱的易受伤害性增加。

▲ 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.