《科學》2023年9月最新一期主要內容摘要

編譯 | 李言

Science, 29 SEP 2023, Volume 381 Issue 6665

《科學》2023年9月29日，第381卷，6665期

化學Chemistry

Diverse functional polyethylenes by catalytic amination

通過催化胺化制得多種功能聚乙烯

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

▲ 鏈接：https://www.science.org/doi/full/10.1126/science.adg6093

▲ 摘要：

我們展示了一種銅催化聚乙烯胺化反應，它可以形成含有一系列極性基團和取代基的單功能和雙功能材料。

我們設計的具有疏水基團的催化劑能夠使線性和支化聚乙烯的胺化，而不會發生鏈斷裂或交聯，從而使聚乙烯具有本應該無法獲得的官能團和結構組合。

由此合成的材料具有可調的體積和表面性能，包括韌性、對金屬的附著力、可涂性和水溶性，這可以拓展功能性聚乙烯的應用，并減少對復雜復合材料的需求。

▲ 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

通過金屬有機框架將氟化氣體作為固體試劑處理

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

▲ 鏈接：https://www.science.org/doi/full/10.1126/science.adg8835

▲ 摘要：

我們報告了使用金屬有機框架（MOFs）作為穩定固體試劑處理氟化氣體的策略。氣體-MOFs試劑通常以克為單位制備，可以用于促進氟酰化和氟烷基化反應。

在蠟內封裝氣體-MOFs試劑使得其可以在工作臺上穩定存儲，并在超聲波后控制釋放到溶液中，這是直接處理氣體的更安全的替代方案。同時，我們的處理方法使這些氣體的高通量反應發展成為可能。

▲ 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.

植物學Botany

An evolutionary epigenetic clock in plants

植物的進化表觀遺傳時鐘

▲ 作者：N. YAO, Z. ZHANG et al.

▲ 鏈接：https://www.science.org/doi/full/10.1126/science.adh9443

▲ 摘要：

在此，我們展示了植物基因組中胞嘧啶子集的隨機DNA甲基化變化顯示出時鐘樣行為。這種“進化時鐘”比基于DNA的時鐘快幾個數量級，可以在幾年到幾個世紀的范圍內進行系統發育研究。

通過實驗，我們證明擬南芥和大葉藻這兩種植物主要的生殖模式中，進化時鐘概括了已知的種內系統發育樹的拓撲結構和分支時間。這一發現將為植物生物多樣性的高分辨率時間研究開辟新可能性。

▲ 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.

動物學Zoology

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

融合和裂變循環使非洲慈鯛能夠快速并行適應性輻射

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

▲ 鏈接：https://www.science.org/doi/full/10.1126/science.ade2833

▲ 摘要：

在非洲的維多利亞湖地區，每個湖泊都有一種魚系生物輻射，其中最大型的輻射發生在一個不足16000年的湖泊中。我們發現該地所有的生態行會都是在原地進化的。

通過混合的譜系融合和通過物種形成的譜系裂變的循環是輻射的歷史特征。當居住在沼澤的不同避難種群，在新形成的湖泊中相遇時，它們會融合成一個單一的種群，重新開始了舊種群的混合變異。

每個種群都提供了一組不同的古老等位基因，從這些等位基因中，新的適應性輻射飛速融合，包括額外的聚變-裂變循環。我們認為，在一個譜系的歷史中，重復的聚變-裂變循環使適應性輻射更快發生，同時變得可預測。

▲ 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.

基因組學Genomics

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

社區范圍內的基因組測序揭示了達爾文雀30年的進化歷程

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

▲ 鏈接：https://www.science.org/doi/full/10.1126/science.adf6218

▲ 摘要：

通過利用加拉帕戈斯群島中達芙妮島上3955只達爾文雀的全基因組數據，我們確定了6個可以解釋45%的高度遺傳的勇地雀喙大小變異大效應位點，這是一個關鍵的生態性狀。

主要位點是一個由4個基因組成的超基因。基因座等位基因頻率的突變伴隨著干旱期間自然選擇引起的喙大小的強烈變化。由于與勇地雀的漸進雜交，在30年的時間里，仙人掌地雀逐漸發生了變化。

▲ 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

瀕危鹿角珊瑚抗病的基因組特征

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

▲ 鏈接：https://www.science.org/doi/full/10.1126/science.adi3601

▲ 摘要：

白帶病（WBD）導致加勒比海鹿角珊瑚的數量大大減少，以致其目前被列為極度瀕危物種。高度抗病的鹿角珊瑚基因型存在，但抗病的遺傳基礎尚不清楚。

通過實驗將新基因組和來自佛羅里達州及巴拿馬的76種鹿角珊瑚基因型的全基因組重測序，我們確定了與疾病抗性相關的10個基因組區域和73個單核苷酸多態性，包括涉及珊瑚免疫和病原體檢測的4個基因的功能性蛋白質編碼變化。

從10個基因組位點計算出的多基因得分表明，遺傳篩選可以在整個加勒比地區檢測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.