编译|李言

Science, 3 JAN 2025, Volume 387 Issue 6729

《科学》2025年1月3日，第387卷，6729期

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化学Chemistry

Landscape profiling of PET depolymerases using a natural sequence cluster framework

使用自然序列聚类框架进行PET解聚合酶景观分析

▲ 作者：HOGYUN SEO, HWASEOK HONG et al.

▲ 链接：https://www.science.org/doi/10.1126/science.adp5637

▲ 摘要：研究者们已经能够从天然来源中鉴别出分解聚合物的酶，并用于工业上的塑料回收。然而，仍有许多酶优化的潜在起点没有被开发。我们生成了1894个聚对苯二甲酸乙二醇酯解聚合酶（PETase）候选物的170个谱系，并使用与PET降解能力相关的采样方法进行了分析。

我们确定了三个有前景但尚未被开发的PETase谱系和两个有效的PETase，Mipa-P和Kubu-P。Kubu-P的一个工程变体在恶劣环境下的PET解聚 性能优于基准，例如在高底物负荷和乙二醇作为溶剂的环境下。

▲ Abstract：Enzymes capable of breaking down polymers have been identified from natural sources and developed for industrial use in plastic recycling. However, there are many potential starting points for enzyme optimization that remain unexplored. We generated a landscape of 170 lineages of 1894 polyethylene terephthalate depolymerase (PETase) candidates and performed profiling using sampling approaches with features associated with PET-degrading capabilities. We identified three promising yet unexplored PETase lineages and two potent PETases, Mipa-P and Kubu-P. An engineered variant of Kubu-P outperformed benchmarks in terms of PET depolymerization in harsh environments, such as those with high substrate load and ethylene glycol as the solvent.

医学Medicine

Rare germline structural variants increase risk for pediatric solid tumors

罕见的种系结构变异增加儿童患实体瘤的风险

▲ 作者：RIAZ GILLANI, RYAN L. COLLINS et al.

▲ 链接：https://www.science.org/doi/10.1126/science.adq0071

▲ 摘要：儿童实体瘤是儿童疾病死亡的主要原因之一。在这项研究中，我们通过对1765名患病儿童、943名未患病的父母和6665名成人对照的种系基因组测序，研究了作为儿童颅外实体瘤危险因素的种系结构变异（SVs）。

我们发现，在男孩中存在很大的种系染色体异常与实体瘤风险增加之间基于性别的关联。在神经母细胞瘤中，种系SVs的总体影响最大，我们发现了导致高表达、突变约束基因功能丧失的超稀有SVs负担，以及预计会破坏染色质结构域边界的非编码SVs。

总的来说，我们估计罕见的种系SVs可以解释1.1%—5.6%的儿童癌症易感性，确定它们是疾病易感性的重要组成部分。

▲ Abstract：Pediatric solid tumors are a leading cause of childhood disease mortality. In this work, we examined germline structural variants (SVs) as risk factors for pediatric extracranial solid tumors using germline genome sequencing of 1765 affected children, their 943 unaffected parents, and 6665 adult controls. We discovered a sex-biased association between very large (>1 megabase) germline chromosomal abnormalities and increased risk of solid tumors in male children. The overall impact of germline SVs was greatest in neuroblastoma, where we uncovered burdens of ultrarare SVs that cause loss of function of highly expressed, mutationally constrained genes, as well as noncoding SVs predicted to disrupt chromatin domain boundaries. Collectively, we estimate that rare germline SVs explain 1.1 to 5.6% of pediatric cancer liability, establishing them as an important component of disease predisposition.

地球科学Earth Science

Recent global temperature surge intensified by record-low planetary albedo

历史新低的行星反照率加剧了近期全球气温升高

▲ 作者：HELGE F. GOESSLING, THOMAS RACKOW, AND THOMAS JUNG

▲ 链接：https://www.science.org/doi/10.1126/science.adq7280

▲摘要：2023年，全球平均气温比工业化前高出近1.5k，比之前的记录高出约0.17k。包括人为变暖和厄尔尼诺现象在内的已知驱动因素的先前最佳估计，可以解释气温上升时大约缺少的0.2k。

利用卫星和再分析数据，我们确定历史新低的行星反照率是引起这一差距的主要因素。这种下降显然是由北半球中纬度和热带地区低云覆盖的减少所引起的，这是多年趋势的延续。

对低云趋势进行继续探索，并了解其中有多少是由于内部变率、减少的气溶胶浓度，或可能正在出现的低云反馈，对于评估当前和预期的未来变暖至关重要。

▲ Abstract：In 2023, the global mean temperature soared to almost 1.5 kelvin above the preindustrial level, surpassing the previous record by about 0.17 kelvin. Previous best-guess estimates of known drivers, including anthropogenic warming and the El Ni?o onset, fall short by about 0.2 kelvin in explaining the temperature rise. Using satellite and reanalysis data, we identified a record-low planetary albedo as the primary factor bridging this gap. The decline is apparently caused largely by a reduced low-cloud cover in the northern mid-latitudes and tropics, in continuation of a multiannual trend. Further exploring the low-cloud trend and understanding how much of it is due to internal variability, reduced aerosol concentrations, or a possibly emerging low-cloud feedback will be crucial for assessing the present and expected future warming.

Canadian forests are more conducive to high-severity fires in recent decades

近几十年来，加拿大的森林更容易发生严重火灾

▲ 作者：WEIWEI WANG, XIANLI WANG et al.

▲ 链接：https://www.science.org/doi/10.1126/science.ado1006

▲摘要：这项研究确定了加拿大森林中火灾严重性的驱动因素，并估计了其时空变化情况。我们的结果显示，干旱的可燃物是火灾严重性的最有影响力的驱动因素，夏季月份更容易发生严重火灾，而北部地区受气候变化的影响最大。

约6%（0.54%至14.64%）的模拟区域在1981年至2020年期间显示出有利于非常严重火灾的天数显著增加，其中大部分增加发生在2001年至2020年以及春季和秋季。2023年的严重火灾展示了类似的空间模式，但火灾严重性的升级更为广泛。

▲ Abstract：This study identifies driving forces of burn severity and estimates its spatiotemporal variations in Canadian forests. Our results show that fuel aridity was the most influential driver of burn severity, summer months were more prone to severe burning, and the northern areas were most influenced by the changing climate. About 6% (0.54 to 14.64%) of the modeled areas show significant increases in the number of days conducive to high-severity burning during 1981 to 2020, most of which were found during 2001 to 2020 and in the spring and autumn. The extraordinary 2023 fire season demonstrated similar spatial patterns but more-widespread escalations in burn severity.

生物学Biology

Bats surf storm fronts during spring migration

蝙蝠春季迁徙时在风暴锋面“滑行”

▲ 作者：EDWARD HURME, IVAN LENZI et al.

▲ 链接：https://www.science.org/doi/10.1126/science.ade7441

▲ 摘要：长距离迁徙在鸣禽中很常见，但在蝙蝠中却很罕见且研究不足。我们通过使用一个具有机载处理能力的、1.2克的物联网（IoT）标签进行测试，追踪了雌性普通夜蝠（Nyctalus noctula）在春季迁徙期间穿越中欧的日常位置、温度和活动，距离长达1116公里。

在3年的时间里，71只蝙蝠每晚迁徙数十至数百公里，主要是得益于暖锋的到来为它们提供的风力支持。蝙蝠还显示出在迁徙途中遇到各种不同情况时所需要的、令人意想不到的灵活性。

然而，在风暴季节末离开的雌性在每次旅行距离上的总活动量更高，这可能是它们为灵活迁徙时间所付出的代价。

▲ Abstract：Long-distance migration, common in passerine birds, is rare and poorly studied in bats. Piloting a 1.2-gram IoT (Internet of Things) tag with onboard processing, we tracked the daily location, temperature, and activity of female common noctules (Nyctalus noctula) during spring migration across central Europe up to 1116 kilometers. Over 3 years, 71 bats migrated tens to hundreds of kilometers per night, predominantly with incoming warm fronts, which provided them with wind support. Bats also showed unexpected flexibility in their ability to migrate across a wide range of conditions if needed. However, females leaving toward the end of the season showed higher total activity per distance traveled, a possible cost for their flexible migration timing.

Competitive social feedback amplifies the role of early life contingency in male mice

竞争性社会反馈放大了雄性小鼠早期生活偶然性的作用

▲ 作者：MATTHEW N. ZIPPLE, DANIEL CHANG KUO et al.

▲ 链接：https://www.science.org/doi/10.1126/science.adq0579

▲摘要：早期生活中的偶然性（或“运气”）在塑造个体发展中起重要作用。通过比较功能上基因相同但经历过不同资源竞争水平（雄性）或者没有经历过不同资源竞争水平（雌性）的自由生活小鼠的发展轨迹，我们展示了竞争放大了早期的偶然性。

雄性资源竞争导致一个放大了早期偶然性的重要性、将个体推向不同的自我强化的生活轨迹的反馈循环，而这一过程在雌性中似乎不存在。我们的结果表明，性选择的强度可能是自我限制的，它们强调了即使在没有任何潜在能力差异的情况下，偶然性可能导致生活结果的差异。

▲ Abstract：Contingency (or “luck”) in early life plays an important role in shaping individuals’ development. By comparing the developmental trajectories of functionally genetically identical free-living mice who either experienced high levels of resource competition (males) or did not (females), we show that competition magnifies early contingency. Male resource competition results in a feedback loop that magnifies the importance of early contingency and pushes individuals onto divergent, self-reinforcing life trajectories, while the same process appears absent in females. Our results indicate that the strength of sexual selection may be self-limiting, and they highlight the potential for contingency to lead to differences in life outcomes, even in the absence of any underlying differences in ability (“merit”).