编译 | 李言

Science, 9 May 2025, VOL 388, ISSUE 6747

《科学》2025年5月9日，第388卷，6747期

生物学Biology

Convergent acquisition of disulfide-forming enzymes in malodorous flowers

臭味花卉中二硫键形成酶的趋同获得

▲ 作者：Yudai Okuyama, Kenji Fukushima et al.

▲链接：

https://www.science.org/doi/10.1126/science.adu8988

▲摘要：

能够识别赋予进化新颖性的代谢和遗传变化，对于理解促进或限制特征发生的因素至关重要。

二甲基二硫（DMDS）是一种可以吸引腐肉传粉者挥发性化合物。我们发现它是由一种二硫合酶（DSS）在马兜铃科植物Asarum属中产生的。DSS源于甲硫醇氧化酶（MTOX），是一种在动物和植物中保守的酶，类似的DSS酶在其他两个植物属中独立进化。

在独立起源的DSS中共享的三个氨基酸变化足以引起MTOX和DSS之间的功能切换。少量的氨基酸变化和高度保守的酶的共同选择可能解释了为什么DMDS在拟花物种中广泛存在。

▲ Abstract：

Identifying the metabolic and genetic changes that confer evolutionary novelty is essential for understanding the factors facilitating or constraining the occurrence of traits. We show that dimethyl disulfide (DMDS), a volatile compound that attracts saprophilous pollinators, is produced by a disulfide synthase (DSS) in the plant genus Asarum (Aristolochiaceae). DSS is derived from methanethiol oxidase (MTOX), an enzyme conserved among animals and plants, and similar DSS enzymes have independently evolved in two other plant genera. Three amino acid changes shared among the DSSs of independent origins were sufficient to cause a functional switch between MTOX and DSS. The small number of amino acid changes and the co-option of a highly conserved enzyme may explain why DMDS-emitting flowers are widespread among floral mimics.

Mobile integrons encode phage defense systems

移动整合子编码噬菌体防御系统

▲ 作者：Nicolas Kieffer, Alberto Hipólito et al.

▲链接：

https://www.science.org/doi/10.1126/science.ads0915

▲摘要：

整合子是捕获、储存和调节整合子盒中编码基因表达的细菌遗传元件。移动整合子（MIs）作为关键病原体中数百种抗菌素耐药基因的载体，被携带在质粒上。这些元件还携带未知功能的基因盒（gcus），其作用和适应价值仍然未明。

在这项研究中，我们展示了gcus编码噬菌体抗性系统，其中许多是新发现的。噬菌体耐药整合子盒（BRiCs）可以与耐药整合子盒组合和混合，产生多噬菌体或药物和噬菌体耐药性。

BRiCs的适应度成本是可变的，取决于遗传环境，可以通过改变阵列中磁带的顺序来调节。因此，MIs充当了高机动性、低成本的防御功能。

▲ Abstract：

Integrons are bacterial genetic elements that capture, stockpile, and modulate the expression of genes encoded in integron cassettes. Mobile integrons (MIs) are borne on plasmids, acting as a vehicle for hundreds of antimicrobial resistance genes among key pathogens. These elements also carry gene cassettes of unknown function (gcus) whose role and adaptive value remain unexplored. In this work, we show that gcus encode phage resistance systems, many of which are newly discovered. Bacteriophage resistance integron cassettes (BRiCs) can be combined and mixed with resistance cassettes to produce multiphage or drug and phage resistance. The fitness costs of BRiCs are variable and dependent on the genetic context and can be modulated by changing the order of cassettes in the array. Hence, MIs act as highly mobile, low-cost defense islands.

材料科学Materials Science

Spontaneous formation of robust two-dimensional perovskite phases

稳健的二维钙钛矿相的自发形成

▲ 作者：Shaun Tan, Meng-Chen Shih et al.

▲链接：

https://www.science.org/doi/10.1126/science.adr1334

▲摘要：

二维/三维钙钛矿双层异质结构可以提高钙钛矿太阳能电池的稳定性和性能。研究表明，器件中的二维/三维钙钛矿堆叠在其寿命结束期间会发生动态演变。

最初纯相位二维中间层可以演变不同，导致不同的器件稳定性。研究表明使用混合溶剂可以形成稳健的二维中间层，以调节其结晶度和相纯度。由此产生的二维/三维器件达到了25.9%的效率，并且具有良好的耐用性，在85度下使用最大功率点跟踪1074小时后保持了91%的初始性能。

▲ Abstract：

The two-dimensional on three-dimensional (2D/3D) perovskite bilayer heterostructure can improve the stability and performance of perovskite solar cells. We show that the 2D/3D perovskite stack in a device evolves dynamically during its end-of-life decomposition. Initially phase-pure 2D interlayers can evolve differently, resulting in different device stabilities. We show that a robust 2D interlayer can be formed using mixed solvents to regulate its crystallinity and phase purity. The resulting 2D/3D devices achieved 25.9% efficiency and had good durability, retaining 91% of their initial performance after 1074 hours at 85°C using maximum power point tracking.

医学Medicine

Enhanced ERK activity extends ketamine’s antidepressant effects by augmenting synaptic plasticity

通过加强突触可塑性，增强的ERK活性可以扩展氯胺酮的抗抑郁作用

▲ 作者：Z. Zack Ma, Natalie J. Guzikowski et al.

▲链接：

https://www.science.org/doi/10.1126/science.abb6748

▲摘要：

研究发现氯胺酮诱导的CA3-CA1突触增强，可以通过药物抑制双特异性磷酸酶6 （DUSP6）瞬时增加细胞外信号调节激酶（ERK）活性进行加强。

急性氯胺酮治疗的抗抑郁样行为效应可通过抑制DUSP6延长至2个月。兴奋性神经元中原肌球蛋白受体激酶B （TrkB）的选择性缺失消除了这些由DUSP6抑制介导的突触和行为效应。这些数据表明氯胺酮的快速抗抑郁作用可以通过选择性靶向下游细胞内信号传导来维持。

▲ Abstract：

Here, we found that ketamine-induced CA3-CA1 synaptic potentiation could be augmented by transiently increasing extracellular signal–regulated kinase (ERK) activity through pharmacological inhibition of dual-specificity phosphatases 6 (DUSP6). The antidepressant-like behavioral effects of acute ketamine treatment were extended by DUSP6 inhibition for up to 2 months. The selective deletion of tropomyosin receptor kinase B (TrkB) in excitatory neurons abolished these DUSP6 inhibition–mediated synaptic and behavioral effects. These data suggest that ketamine’s rapid antidepressant effects can be sustained by selectively targeting downstream intracellular signaling.

动力学Dynamics

Physical synchronization of soft self-oscillating limbs for fast and autonomous locomotion

用于快速自主运动的软自振荡肢体的物理同步

▲ 作者：Alberto Comoretto, Harmannus A. H. Schomaker et al.

▲链接：

https://www.science.org/doi/10.1126/science.adr3661

▲摘要：

研究介绍了一种快速自主运动策略，通过自振荡肢体与环境之间的物理相互作用，在没有控制信号的情况下产生同步步态。每个肢体都是一种柔软的管子，只需要恒定的空气流就能以300赫兹的频率进行循环运动。

其中几个自振荡肢体的物理同步使运动速度比同类最先进的机器人快几个数量级。通过身体环境动力学，这些看似简单的设备表现出自主性，包括躲避障碍、两栖步态转换和趋光性。

▲ Abstract：

Here, we introduce a rapid and autonomous locomotion strategy with synchronized gaits emerging through physical interactions between self-oscillating limbs and the environment, without control signals. Each limb is a single soft tube that only requires a constant flow of air to perform cyclic stepping motions at frequencies reaching 300 hertz. Physical synchronization of several of these self-oscillating limbs enables locomotion speeds that are orders of magnitude faster than those of comparable state-of-the-art robots. Through body-environment dynamics, these seemingly simple devices exhibit autonomy, including obstacle avoidance, amphibious gait transitions, and phototaxis.

地球科学Earth Science

Reducing emissions and air pollution from informal brick kilns: Evidence from Bangladesh

减少非正规砖窑的排放和空气污染：来自孟加拉国的证据

▲ 作者：Nina Brooks, Debashish Biswas et al.

▲链接：

https://www.science.org/doi/10.1126/science.adr7394

▲摘要：

本研究是孟加拉国一项随机对照试验的结果。该试验引入了276个“之字形”砖窑提高能源效率和减少排放的操作实践。

在所有干预窑中，65%采用了改进的做法。处理分配减少了10.5%的能源使用（p值<0.001），每个窑每年的二氧化碳和PM2.5排放量分别减少了171公吨和0.45公吨。

用每公吨185美元的碳社会成本来评估二氧化碳减排，研究发现社会效益超过成本的比例是65比1。这项干预措施不需要新的资本投资，也降低了燃料成本，提高了砖的质量。研究结果表明，解决“非正规”产业的环境问题，私人和公众都能获益的潜力。

▲ Abstract：

We present results from a randomized controlled trial in Bangladesh that introduced operational practices to improve energy efficiency and reduce emissions in 276 “zigzag” brick kilns. Of all intervention kilns, 65% adopted the improved practices. Treatment assignment reduced energy use by 10.5% (P-value <0.001) and decreased CO2 and PM2.5 emissions by 171 and 0.45 metric tons, respectively, per kiln per year. Valuing the CO2 reductions using a social cost of carbon of 185 USD per metric ton, we find that the social benefits outweigh costs by a factor of 65 to 1. The intervention, which required no new capital investment, also decreased fuel costs and increased brick quality. Our results demonstrate the potential for privately profitable, as well as publicly beneficial, improvements to address environmental problems in informal industries.