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编译 | 李言

Science, 29 SEP 2023, Volume 381 Issue 6665

《明升体育app》2023年9月29日，第381卷，6665期

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明升手机Chemistry

Diverse functional polyethylenes by catalytic amination

通过催化胺化制得多种功能聚乙烯

▲ 作者：NICODEMO R. CICCIA, JAKE X. SHI et al.

▲ 链接：http://www.science.org/doi/full/10.1126/science.adg6093

▲ 摘要：

我们展示了一种铜催化聚乙烯胺化反应，它可以形成含有一系列极性基团和取代基的单功能和双功能材料。

我们设计的具有疏水基团的催化剂能够使线性和支化聚乙烯的胺化，而不会发生链断裂或交联，从而使聚乙烯具有本应该无法获得的官能团和结构组合。

由此合成的材料具有可调的体积和表面性能，包括韧性、对金属的附着力、可涂性和水溶性，这可以拓展功能性聚乙烯的应用，并减少对复杂复合材料的需求。

▲ Abstract：

We report a Cu-catalyzed amination of polyethylenes to form mono- and bifunctional materials containing a series of polar groups and substituents. Designed catalysts with hydrophobic moieties enable the amination of linear and branched polyethylenes without chain scission or cross-linking, leading to polyethylenes with otherwise inaccessible combinations of functional groups and architectures. The resulting materials possess tunable bulk and surface properties, including toughness, adhesion to metal, paintability, and water solubility, which could unlock applications for functional polyethylenes and reduce the need for complex composites.

Handling fluorinated gases as solid reagents using metal-organic frameworks

通过金属有机框架将氟化气体作为固体试剂处理

▲ 作者：KAITLYN T. KEASLER, MARY E. ZICK et al.

▲ 链接：http://www.science.org/doi/full/10.1126/science.adg8835

▲ 摘要：

我们手机版了使用金属有机框架（MOFs）作为稳定固体试剂处理氟化气体的策略。气体-MOFs试剂通常以克为单位制备，可以用于促进氟酰化和氟烷基化反应。

在蜡内封装气体-MOFs试剂使得其可以在工作台上稳定存储，并在超声波后控制释放到溶液中，这是直接处理气体的更安全的替代方案。同时，我们的处理方法使这些气体的高通量反应发展成为可能。

▲ Abstract：

We report a general strategy for handling fluorinated gases as benchtop-stable solid reagents using metal-organic frameworks (MOFs). Gas-MOF reagents are prepared on gram-scale and used to facilitate fluorovinylation and fluoroalkylation reactions. Encapsulation of gas-MOF reagents within wax enables stable storage on the benchtop and controlled release into solution upon sonication, which represents a safer alternative to handling the gas directly. Furthermore, our approach enables high-throughput reaction development with these gases.

植物学Botany

An evolutionary epigenetic clock in plants

植物的进化表观遗传时钟

▲ 作者：N. YAO, Z. ZHANG et al.

▲ 链接：http://www.science.org/doi/full/10.1126/science.adh9443

▲ 摘要：

在此，我们展示了植物基因组中胞嘧啶子集的随机DNA甲基化变化显示出时钟样行为。这种“进化时钟”比基于DNA的时钟快几个数量级，可以在几年到几个世纪的范围内进行系统发育研究。

通过实验，我们证明拟南芥和大叶藻这两种植物主要的生殖模式中，进化时钟概括了已知的种内系统发育树的拓扑结构和分支时间。这一发现将为植物生物多样性的高分辨率时间研究开辟新可能性。

▲ Abstract：

Here, we demonstrate that stochastic DNA methylation changes at a subset of cytosines in plant genomes display a clocklike behavior. This “epimutation clock” is orders of magnitude faster than DNA-based clocks and enables phylogenetic explorations on a scale of years to centuries. We show experimentally that epimutation clocks recapitulate known topologies and branching times of intraspecies phylogenetic trees in the self-fertilizing plant Arabidopsis thaliana and the clonal seagrass Zostera marina, which represent two major modes of plant reproduction. This discovery will open new possibilities for high-resolution temporal studies of plant biodiversity.

动物学Zoology

Cycles of fusion and fission enabled rapid parallel adaptive radiations in African cichlids

融合和裂变循环使非洲慈鲷能够快速并行适应性辐射

▲ 作者：JOANA I. MEIER, MATTHEW D. MCGEE, DAVID A. MARQUES et al.

▲ 链接：http://www.science.org/doi/full/10.1126/science.ade2833

▲ 摘要：

在非洲的维多利亚湖地区，每个湖泊都有一种鱼系生物辐射，其中最大型的辐射发生在一个不足16000年的湖泊中。我们发现该地所有的生态行会都是在原地进化的。

通过混合的谱系融合和通过物种形成的谱系裂变的循环是辐射的历史特征。当居住在沼泽的不同避难种群，在新形成的湖泊中相遇时，它们会融合成一个单一的种群，重新开始了旧种群的混合变异。

每个种群都提供了一组不同的古老等位基因，从这些等位基因中，新的适应性辐射飞速融合，包括额外的聚变-裂变循环。我们认为，在一个谱系的历史中，重复的聚变-裂变循环使适应性辐射更快发生，同时变得可预测。

▲ Abstract：

In Africa’s Lake Victoria region, one cichlid lineage radiated in every lake, with the largest radiation taking place in a lake less than 16,000 years old. We show that all of its ecological guilds evolved in situ. Cycles of lineage fusion through admixture and lineage fission through speciation characterize the history of the radiation. It was jump-started when several swamp-dwelling refugial populations, each of which were of older hybrid descent, met in the newly forming lake, where they fused into a single population, resuspending old admixture variation. Each population contributed a different set of ancient alleles from which a new adaptive radiation assembled in record time, involving additional fusion-fission cycles. We argue that repeated fusion-fission cycles in the history of a lineage make adaptive radiation fast and predictable.

基因组学Genomics

Community-wide genome sequencing reveals 30 years of Darwin’s finch evolution

社区范围内的基因组测序揭示了达尔文雀30年的进化历程

▲ 作者：ERIK D. ENBODY, ASHLEY T. SENDELL-PRICE, C. GRACE SPREHN et al.

▲ 链接：http://www.science.org/doi/full/10.1126/science.adf6218

▲ 摘要：

通过利用加拉帕戈斯群岛中达芙妮岛上3955只达尔文雀的全基因组数据，我们确定了6个可以解释45%的高度遗传的勇地雀喙大小变异大效应位点，这是一个关键的生态性状。

主要位点是一个由4个基因组成的超基因。基因座等位基因频率的突变伴随着干旱期间自然选择引起的喙大小的强烈变化。由于与勇地雀的渐进杂交，在30年的时间里，仙人掌地雀逐渐发生了变化。

▲ Abstract：

Using whole-genome data of 3955 of Darwin’s finches on the Galápagos Island of Daphne Major, we identified six loci of large effect that explain 45% of the variation in the highly heritable beak size of Geospiza fortis, a key ecological trait. The major locus is a supergene comprising four genes. Abrupt changes in allele frequencies at the loci accompanied a strong change in beak size caused by natural selection during a drought. A gradual change in Geospiza scandens occurred across 30 years as a result of introgressive hybridization with G. fortis.

Genomic signatures of disease resistance in endangered staghorn corals

濒危鹿角珊瑚抗病的基因组特征

▲ 作者：STEVEN V. VOLLMER, JASON D. SELWYN et al.

▲ 链接：http://www.science.org/doi/full/10.1126/science.adi3601

▲ 摘要：

白带病（WBD）导致加勒比海鹿角珊瑚的数量大大减少，以致其目前被列为极度濒危物种。高度抗病的鹿角珊瑚基因型存在，但抗病的遗传基础尚不清楚。

通过实验将新基因组和来自佛罗里达州及巴拿马的76种鹿角珊瑚基因型的全基因组重测序，我们确定了与疾病抗性相关的10个基因组区域和73个单核苷酸多态性，包括涉及珊瑚免疫和病原体检测的4个基因的功能性蛋白质编码变化。

从10个基因组位点计算出的多基因得分表明，遗传筛选可以在整个加勒比地区检测到野生及培育鹿角珊瑚群的抗疾病能力。

▲ Abstract：

White band disease (WBD) has caused unprecedented declines in the Caribbean Acropora corals, which are now listed as critically endangered species. Highly disease-resistant Acropora cervicornis genotypes exist, but the genetic underpinnings of disease resistance are not understood. Using transmission experiments, a newly assembled genome, and whole-genome resequencing of 76 A. cervicornis genotypes from Florida and Panama, we identified 10 genomic regions and 73 single-nucleotide polymorphisms that are associated with disease resistance and that include functional protein-coding changes in four genes involved in coral immunity and pathogen detection. Polygenic scores calculated from 10 genomic loci indicate that genetic screens can detect disease resistance in wild and nursery stocks of A. cervicornis across the Caribbean.