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1.
Cell ; 186(11): 2313-2328.e15, 2023 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-37146612

RESUMO

Hybrid potato breeding will transform the crop from a clonally propagated tetraploid to a seed-reproducing diploid. Historical accumulation of deleterious mutations in potato genomes has hindered the development of elite inbred lines and hybrids. Utilizing a whole-genome phylogeny of 92 Solanaceae and its sister clade species, we employ an evolutionary strategy to identify deleterious mutations. The deep phylogeny reveals the genome-wide landscape of highly constrained sites, comprising ∼2.4% of the genome. Based on a diploid potato diversity panel, we infer 367,499 deleterious variants, of which 50% occur at non-coding and 15% at synonymous sites. Counterintuitively, diploid lines with relatively high homozygous deleterious burden can be better starting material for inbred-line development, despite showing less vigorous growth. Inclusion of inferred deleterious mutations increases genomic-prediction accuracy for yield by 24.7%. Our study generates insights into the genome-wide incidence and properties of deleterious mutations and their far-reaching consequences for breeding.


Assuntos
Melhoramento Vegetal , Solanum tuberosum , Diploide , Mutação , Filogenia , Solanum tuberosum/genética
2.
Nature ; 606(7914): 535-541, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35676481

RESUMO

Potato (Solanum tuberosum L.) is the world's most important non-cereal food crop, and the vast majority of commercially grown cultivars are highly heterozygous tetraploids. Advances in diploid hybrid breeding based on true seeds have the potential to revolutionize future potato breeding and production1-4. So far, relatively few studies have examined the genome evolution and diversity of wild and cultivated landrace potatoes, which limits the application of their diversity in potato breeding. Here we assemble 44 high-quality diploid potato genomes from 24 wild and 20 cultivated accessions that are representative of Solanum section Petota, the tuber-bearing clade, as well as 2 genomes from the neighbouring section, Etuberosum. Extensive discordance of phylogenomic relationships suggests the complexity of potato evolution. We find that the potato genome substantially expanded its repertoire of disease-resistance genes when compared with closely related seed-propagated solanaceous crops, indicative of the effect of tuber-based propagation strategies on the evolution of the potato genome. We discover a transcription factor that determines tuber identity and interacts with the mobile tuberization inductive signal SP6A. We also identify 561,433 high-confidence structural variants and construct a map of large inversions, which provides insights for improving inbred lines and precluding potential linkage drag, as exemplified by a 5.8-Mb inversion that is associated with carotenoid content in tubers. This study will accelerate hybrid potato breeding and enrich our understanding of the evolution and biology of potato as a global staple food crop.


Assuntos
Produtos Agrícolas , Evolução Molecular , Genoma de Planta , Solanum tuberosum , Produtos Agrícolas/genética , Genoma de Planta/genética , Melhoramento Vegetal , Tubérculos/genética , Solanum tuberosum/genética
3.
Proc Natl Acad Sci U S A ; 120(24): e2222041120, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37276420

RESUMO

Domesticated grapevines spread to Europe around 3,000 years ago. Previous studies have revealed genomic signals of introgression from wild to cultivated grapes in Europe, but the time, mode, genomic pattern, and biological effects of these introgression events have not been investigated. Here, we studied resequencing data from 345 samples spanning the distributional range of wild (Vitis vinifera ssp. sylvestris) and cultivated (V. vinifera ssp. vinifera) grapes. Based on machine learning-based population genetic analyses, we detected evidence for a single domestication of grapevine, followed by continuous gene flow between European wild grapes (EU) and cultivated grapes over the past ~2,000 y, especially from EU to wine grapes. We also inferred that soft-selective sweeps were the dominant signals of artificial selection. Gene pathways associated with the synthesis of aromatic compounds were enriched in regions that were both selected and introgressed, suggesting EU wild grapes were an important resource for improving the flavor of cultivated grapes. Despite the potential benefits of introgression in grape improvement, the introgressed fragments introduced a higher deleterious burden, with most deleterious SNPs and structural variants hidden in a heterozygous state. Cultivated wine grapes have benefited from adaptive introgression with wild grapes, but introgression has also increased the genetic load. In general, our study of beneficial and harmful effects of introgression is critical for genomic breeding of grapevine to take advantage of wild resources.


Assuntos
Domesticação , Vitis , Europa (Continente) , Genômica , Análise de Sequência de DNA , Vitis/genética
4.
PLoS Genet ; 19(6): e1010811, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37339133

RESUMO

Conservation of crop wild relatives is critical for plant breeding and food security. The lack of clarity on the genetic factors that lead to endangered status or extinction create difficulties when attempting to develop concrete recommendations for conserving a citrus wild relative: the wild relatives of crops. Here, we evaluate the conservation of wild kumquat (Fortunella hindsii) using genomic, geographical, environmental, and phenotypic data, and forward simulations. Genome resequencing data from 73 accessions from the Fortunella genus were combined to investigate population structure, demography, inbreeding, introgression, and genetic load. Population structure was correlated with reproductive type (i.e., sexual and apomictic) and with a significant differentiation within the sexually reproducing population. The effective population size for one of the sexually reproducing subpopulations has recently declined to ~1,000, resulting in high levels of inbreeding. In particular, we found that 58% of the ecological niche overlapped between wild and cultivated populations and that there was extensive introgression into wild samples from cultivated populations. Interestingly, the introgression pattern and accumulation of genetic load may be influenced by the type of reproduction. In wild apomictic samples, the introgressed regions were primarily heterozygous, and genome-wide deleterious variants were hidden in the heterozygous state. In contrast, wild sexually reproducing samples carried a higher recessive deleterious burden. Furthermore, we also found that sexually reproducing samples were self-incompatible, which prevented the reduction of genetic diversity by selfing. Our population genomic analyses provide specific recommendations for distinct reproductive types and monitoring during conservation. This study highlights the genomic landscape of a wild relative of citrus and provides recommendations for the conservation of crop wild relatives.


Assuntos
Citrus , Citrus/genética , Melhoramento Vegetal , Genoma , Genômica , Produtos Agrícolas/genética , Variação Genética
5.
Plant Physiol ; 195(2): 1401-1413, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38285049

RESUMO

Plant domestication are evolutionary experiments conducted by early farmers since thousands years ago, during which the crop wild progenitors are artificially selected for desired agronomic traits along with dramatic genomic variation in the course of moderate to severe bottlenecks. However, previous investigations are mainly focused on small-effect variants, while changes in gene contents are rarely investigated due to the lack of population-level assemblies for both the crop and its wild relatives. Here, we applied comparative genomic analyses to discover gene gain and loss during grapevine domestication using long-read assemblies of representative population samples for both domesticated grapevines (V. vinifera ssp. vinifera) and their wild progenitors (V. vinifera ssp. sylvestris). Only ∼7% of gene families were shared by 16 Vitis genomes while ∼8% of gene families were specific to each accession, suggesting dramatic variations of gene contents in grapevine genomes. Compared to wild progenitors, the domesticated accessions exhibited an increased presence of genes associated with asexual reproduction, while the wild progenitors showcased a higher abundance of genes related to pollination, revealing the transition from sexual reproduction to clonal propagation during domestication processes. Moreover, the domesticated accessions harbored fewer disease-resistance genes than wild progenitors. The SVs occurred frequently in aroma and disease-resistance related genes between domesticated grapevines and wild progenitors, indicating the rapid diversification of these genes during domestication. Our study provides insights and resources for biological studies and breeding programs in grapevine.


Assuntos
Domesticação , Genoma de Planta , Genômica , Vitis , Vitis/genética , Genômica/métodos , Genes de Plantas , Produtos Agrícolas/genética
6.
Plant Physiol ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38743633

RESUMO

The cultivated apple (Malus domestica Borkh.) is a cross-pollinated perennial fruit tree of great economic importance. Previous versions of apple reference genomes were unphased, fragmented, and lacked comprehensive insights into the highly heterozygous genome, which impeded genetic studies and breeding programs in apple. In this study, we assembled a haplotype-resolved telomere-to-telomere reference genome for the diploid apple cultivar Golden Delicious. Subsequently, we constructed a pangenome based on twelve assemblies from wild and cultivated apples to investigate different types of resistance gene analogs (RGAs). Our results revealed the dynamics of the gene gain and loss events during apple domestication. Compared with cultivated species, more gene families in wild species were significantly enriched in oxidative phosphorylation, pentose metabolic process, responses to salt, and abscisic acid biosynthesis process. Interestingly, our analyses demonstrated a higher prevalence of RGAs in cultivated apples than their wild relatives, partially attributed to segmental and tandem duplication events in certain RGAs classes. Other types of structural variations, mainly deletions and insertions, have affected the presence and absence of TIR-NB-ARC-LRR (TNL), NB-ARC-LRR (NL), and CC-NB-ARC-LRR (CNL) genes. Additionally, hybridization/introgression from wild species has also contributed to the expansion of resistance genes in domesticated apples. Our haplotype-resolved T2T genome and pangenome provide important resources for genetic studies of apples, emphasizing the need to study the evolutionary mechanisms of resistance genes in apple breeding programs.

7.
Nucleic Acids Res ; 51(20): 10924-10933, 2023 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-37843097

RESUMO

Detailed knowledge of the genetic variations in diverse crop populations forms the basis for genetic crop improvement and gene functional studies. In the present study, we analyzed a large rice population with a total of 10 548 accessions to construct a rice super-population variation map (RSPVM), consisting of 54 378 986 single nucleotide polymorphisms, 11 119 947 insertion/deletion mutations and 184 736 presence/absence variations. Assessment of variation detection efficiency for different population sizes revealed a sharp increase of all types of variation as the population size increased and a gradual saturation of that after the population size reached 10 000. Variant frequency analysis indicated that ∼90% of the obtained variants were rare, and would therefore likely be difficult to detect in a relatively small population. Among the rare variants, only 2.7% were predicted to be deleterious. Population structure, genetic diversity and gene functional polymorphism of this large population were evaluated based on different subsets of RSPVM, demonstrating the great potential of RSPVM for use in downstream applications. Our study provides both a rich genetic basis for understanding natural rice variations and a powerful tool for exploiting great potential of rare variants in future rice research, including population genetics and functional genomics.


Assuntos
Variação Genética , Oryza , Genética Populacional , Genômica , Oryza/genética , Polimorfismo de Nucleotídeo Único
8.
Proc Natl Acad Sci U S A ; 119(43): e2206076119, 2022 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-36260744

RESUMO

Although interactions between the cytoplasmic and nuclear genomes occurred during diversification of many plants, the evolutionary conflicts due to cytonuclear interactions are poorly understood in crop breeding. Here, we constructed a pan-mitogenome and identified chimeric open reading frames (ORFs) generated by extensive structural variations (SVs). Meanwhile, short reads from 184 accessions of citrus species were combined to construct three variation maps for the nuclear, mitochondrial, and chloroplast genomes. The population genomic data showed discordant topologies between the cytoplasmic and nuclear genomes because of differences in mutation rates and levels of heteroplasmy from paternal leakage. An analysis of species-specific SVs indicated that mitochondrial heteroplasmy was common and that chloroplast heteroplasmy was undetectable. Interestingly, we found a prominent divergence in the mitogenomes and the highest genetic load in the, which may provide the basis for cytoplasmic male sterility (CMS) and thus influence the reshuffling of the cytoplasmic and nuclear genomes during hybridization. Using cytoplasmic replacement experiments, we identified a type of species-specific CMS in mandarin related to two chimeric mitochondrial genes. Our analyses indicate that cytoplasmic genomes from mandarin have rarely been maintained in hybrids and that paternal leakage produced very low levels of mitochondrial heteroplasmy in mandarin. A genome-wide association study (GWAS) provided evidence for three nuclear genes that encode pentatricopeptide repeat (PPR) proteins contributing to the cytonuclear interactions in the Citrus genus. Our study demonstrates the occurrence of evolutionary conflicts between cytoplasmic and nuclear genomes in citrus and has important implications for genetics and breeding.


Assuntos
Citrus , Genoma de Cloroplastos , Domesticação , Citrus/genética , Estudo de Associação Genômica Ampla , Melhoramento Vegetal , Genoma de Cloroplastos/genética
9.
Acc Chem Res ; 56(13): 1766-1779, 2023 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-37314368

RESUMO

Development of multifunctional nanoparticles (NPs) with desired properties is a significant topic in the field of nanotechnology and has been anticipated to revolutionize cancer diagnosis and treatment modalities. The surface character is one of the most important parameters of NPs that can directly affect their in vivo fate, bioavailability, and final theranostic outcomes and thus should be carefully tuned to maximize the diagnosis and treatment effects while minimizing unwanted side effects. Surface engineered NPs have utilized various surface functionality types and approaches to meet the requirements of cancer therapy and imaging. Despite the various strategies, these surface modifications generally serve similar purposes, namely, introducing therapeutic/imaging modules, improving stability and circulation, enhancing targeting ability, and achieving controlled functions. These surface engineered NPs hence could be applied in various cancer diagnosis and treatment scenarios and continuously contribute to the clinical translation of the next-generation NP-based platforms toward cancer theranostics.In this Account, we present recent advances and research efforts on the development of NP surface engineering toward cancer theranostics. First, we summarize the general strategies for NP surface engineering. Various types of surface functionalities have been applied including inorganic material-based functionality, organic material-based functionality like small molecules, polymers, nucleic acids, peptides, proteins, carbohydrates, antibodies, etc., and biomembrane-based functionality. These surface modifications can be realized by prefabrication or postfabrication functionalization, driven by covalent conjugations or noncovalent interactions. Second, we highlight the general aims of these different NPs surface functionalities. Different therapeutic and diagnostic modules, such as nanozymes, antibodies, and imaging contrast agents, have been modified on the surface of NPs to achieve theranostic function. Surface modification also can improve stability and circulation of NPs by protecting the NPs from immune recognition and clearance. In addition, to achieve targeted therapy and imaging, various targeting moieties have been attached on the NP surface to enhance active targeting ability to tissues or cells of interest. Furthermore, the NP surfaces can be tailored to achieve controlled functions which only respond to specific internal (e.g., pH, thermal, redox, enzyme, hypoxia) or external (e.g., light, ultrasound) triggers at the precise action sites. Finally, we present our perspective on the remaining challenges and future developments in this significant and rapidly evolving field. We hope this Account can offer an insightful overlook on the recent progress and an illuminating prospect on the advanced strategies, promoting more attention in this area and adoption by more scientists in various research fields, accelerating the development of NP surface engineering with a solid foundation and broad cancer theranostics applications.


Assuntos
Nanopartículas , Neoplasias , Humanos , Medicina de Precisão , Neoplasias/diagnóstico por imagem , Neoplasias/terapia , Nanopartículas/uso terapêutico , Nanopartículas/química , Engenharia
10.
Chemistry ; 30(3): e202302816, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-37933713

RESUMO

The selective semihydrogenation of C2 H2 to C2 H4 in crude C2 H4 (with ~1 vol % C2 H2 contamination) is a crucial process in the manufacture of polyethylene. Comparing to conventional thermalcatalytic route with Pd as catalyst under high temperature with H2 as hydrogen source, photocatalytic C2 H2 reduction reaction with H2 O as hydrogen source can achieve high selectivity under milder conditions, but has rarely been reported. Here, we present a kind of ultrathin metal-organic framework nanosheets (Cu-Co-MNSs) that demonstrate excellent catalytic activities in the semihydrogenation of C2 H2 . Employing Ru(bpy)3 2+ as the photosensitizer, this catalyst attains a noteworthy turnover number (TON) of 2124 for C2 H4 , coupled with an impressive selectivity of 99.5 % after 12 h visible light irradiation. This performance is comparable to molecular catalysts and notably surpasses the efficiency of bulk metal-organic framework materials. Furthermore, Cu-Co-MNSs achieve a 99.95 % conversion of C2 H2 under industrial relevant conditions (1.10 % C2 H2 in C2 H4 ) with 90.3 % selectivity for C2 H4 over C2 H6 , demonstrating a great potential for polymer-grade C2 H4 production.

11.
Chemistry ; : e202402231, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39008402

RESUMO

Supramolecular polymers (SPs) are constructed through non-covalent interactions. The dynamic or reversible nature of SPs endows them unique physical and chemical properties, such as self-adaptive and stimuli-response abilities. The topological structures of SPs play an important role in determining the physicochemical properties and functionality. Hyperbranched polymers (HBPs) are highly branched 3D macromolecules with linear, dendritic, and terminal units, which makes them versatile candidates for the construction of SPs with fascinating architectures. The resultant HBP-based SPs perfectly integrated the dynamic/reversible nature of SPs and the 3D topological features and multifunctionality of HBP polymers. To date, various types of HBP-based SPs and their assemblies have been constructed, and their potential applications have been explored as well. This article overviews the current progress on self-assembly of HBP-based SPs. The strategies for construction of HBP-based SPs and their assemblies are discussed. Typical potential applications of the assemblies of HBP-based SPs are also introduced.

12.
Phys Chem Chem Phys ; 26(16): 12806-12819, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38619877

RESUMO

Combining the phosphonic acid group with the sulfonic acid group in PEMs has been shown to be an effective strategy for improving the fuel cell performance. However, the interplay of two different ionic groups and the resulting effect on the membrane properties have not been fully elucidated. Here, we used classical molecular dynamics simulation to investigate the morphologies, transport properties and effects of ionic groups in a novel perfluorinated PEM containing two ionic groups (PFSA-PFPA) in comparison to the corresponding homopolymers. Phase separations between hydrophilic and hydrophobic domains are confirmed in these PEMs and result from the evolution of water clusters formed around the ionic groups. The combination of both ionic groups brings a complicated morphological feature in PFSA-PFPA, with near-cylindrical aqueous domains of large length scales interconnected by tortuous domains of small sizes. And we found that the self-diffusion coefficients of water molecules are strongly related to morphologies, with the water transport in PFSA-PFPA lying between two analogous homopolymers. At the molecular level, we found that the sulfonic and phosphonic acid groups have distinct effects on the coordination behaviors and the dynamics of water molecules and hydronium ions. Strong electrostatic interactions lead to compact coordination structures and sluggish dynamics of hydronium ions around phosphonic acid groups, which determine the morphological evolution and transport properties in PFSA-PFPA. Our study affords insights into the relationship between molecular characteristics and transport properties bridged by phase-separated morphologies in a novel PEM containing both sulfonic acid and phosphonic acid groups, which deepens the understanding of the interplay between two ionic groups and may inspire the rational design of high-performance PEMs.

13.
Chem Soc Rev ; 52(5): 1529-1548, 2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36786068

RESUMO

Digital synthetic polymers with uniform chain lengths and defined monomer sequences have recently become intriguing alternatives to traditional silicon-based information devices or natural biomacromolecules for data storage. The structural diversity of information-containing macromolecules endows the digital synthetic polymers with higher stability and storage density but less occupied space. Through subtly designing each unit of coded structure, the information can be readily encoded into digital synthetic polymers in a more economical scheme and more decodable, opening up new avenues for molecular digital data storage with high-level security. This tutorial review summarizes recent advances in salient features of digital synthetic polymers for data storage, including encoding, decoding, editing, erasing, encrypting, and repairing. The current challenges and outlook are finally discussed to offer potential solution guidance and new perspectives for the creation of next-generation digital synthetic polymers and broaden the scope of their applicability.

14.
Nano Lett ; 23(12): 5842-5850, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-36995289

RESUMO

Plasmonic polymeric nanoassemblies offer valuable opportunities in photoconversion applications. Localized surface plasmon mechanisms behind such nanoassemblies govern their functionalities under light illumination. However, an in-depth investigation at the single nanoparticle (NP) level is still challenging, especially when the buried interface is involved, due to the availability of suitable techniques. Here, we synthesized an anisotropic heterodimer composed of a self-assembled polymer vesicle (THPG) capped with a single gold NP, enabling an 8-fold enhancement in hydrogen generation compared to the nonplasmonic THPG vesicle. We explored the anisotropic heterodimer at the single particle level by employing advanced transmission electron microscopes, including one equipped with a femtosecond pulsed laser, which allows us to visualize the polarization- and frequency-dependent distribution of the enhanced electric near fields at the vicinity of Au cap and Au-polymer interface. These elaborated fundamental findings may guide designing new hybrid nanostructures tailored for plasmon-related applications.

15.
J Integr Plant Biol ; 66(7): 1408-1426, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38578160

RESUMO

Structural variations (SVs) are a feature of plant genomes that has been largely unexplored despite their significant impact on plant phenotypic traits and local adaptation to abiotic and biotic stress. In this study, we employed woolly grape (Vitis retordii), a species native to the tropical and subtropical regions of East Asia with both coastal and inland habitats, as a valuable model for examining the impact of SVs on local adaptation. We assembled a haplotype-resolved chromosomal reference genome for woolly grape, and conducted population genetic analyses based on whole-genome sequencing (WGS) data from coastal and inland populations. The demographic analyses revealed recent bottlenecks in all populations and asymmetric gene flow from the inland to the coastal population. In total, 1,035 genes associated with plant adaptive regulation for salt stress, radiation, and environmental adaptation were detected underlying local selection by SVs and SNPs in the coastal population, of which 37.29% and 65.26% were detected by SVs and SNPs, respectively. Candidate genes such as FSD2, RGA1, and AAP8 associated with salt tolerance were found to be highly differentiated and selected during the process of local adaptation to coastal habitats in SV regions. Our study highlights the importance of SVs in local adaptation; candidate genes related to salt stress and climatic adaptation to tropical and subtropical environments are important genomic resources for future breeding programs of grapevine and its rootstocks.


Assuntos
Vitis , Vitis/genética , Adaptação Fisiológica/genética , Genoma de Planta/genética , Genética Populacional , Polimorfismo de Nucleotídeo Único/genética , Tolerância ao Sal/genética , Variação Estrutural do Genoma/genética , Genômica , Genes de Plantas
16.
J Integr Plant Biol ; 66(2): 196-207, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38158885

RESUMO

Rice (Oryza sativa) is a significant crop worldwide with a genome shaped by various evolutionary factors. Rice centromeres are crucial for chromosome segregation, and contain some unreported genes. Due to the diverse and complex centromere region, a comprehensive understanding of rice centromere structure and function at the population level is needed. We constructed a high-quality centromere map based on the rice super pan-genome consisting of a 251-accession panel comprising both cultivated and wild species of Asian and African rice. We showed that rice centromeres have diverse satellite repeat CentO, which vary across chromosomes and subpopulations, reflecting their distinct evolutionary patterns. We also revealed that long terminal repeats (LTRs), especially young Gypsy-type LTRs, are abundant in the peripheral CentO-enriched regions and drive rice centromere expansion and evolution. Furthermore, high-quality genome assembly and complete telomere-to-telomere (T2T) reference genome enable us to obtain more centromeric genome information despite mapping and cloning of centromere genes being challenging. We investigated the association between structural variations and gene expression in the rice centromere. A centromere gene, OsMAB, which positively regulates rice tiller number, was further confirmed by expression quantitative trait loci, haplotype analysis and clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein 9 methods. By revealing the new insights into the evolutionary patterns and biological roles of rice centromeres, our finding will facilitate future research on centromere biology and crop improvement.


Assuntos
DNA Satélite , Oryza , DNA Satélite/metabolismo , Oryza/genética , Oryza/metabolismo , Sequência de Bases , Centrômero/genética , Genoma de Planta/genética
17.
Angew Chem Int Ed Engl ; 63(27): e202404589, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38654509

RESUMO

Artificial vesicles are recognized as powerful platforms for a large body of research across the disciplines of chemistry, physics and biology. Despite the great progress, control of the size distribution to make uniform vesicles remains fundamentally difficult due to the highly uncontrollable growth kinetics, especially for micron-sized vesicles. Here we report a template-free living self-assembly method to prepare monodisperse vesicles around 1 µm from an alternating copolymer. The polymer forms nanodisks (ca. 9 nm) in N,N-dimethylformamide (DMF), acting as seeds for subsequent growth. By adding water, the nanodisks gradually grow into larger circular bilayer nanosheets, which bend to crowns and continue to grow into uniform micron-sized vesicles. The first-order growth kinetics as well as the small size polydispersity index (<0.1) suggests the living self-assembly characteristics. This work paves a new way in both living self-assembly and monodisperse polymer vesicles.

18.
Angew Chem Int Ed Engl ; : e202408345, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38888253

RESUMO

Membrane materials that resist nonspecific or specific adsorption are urgently required in widespread applications. In water purification, inevitable membrane fouling not only limits separation performance, but also remarkably increases operation requirements, and augments extra maintenance costs and higher energy consumption. In this work, we report a freestanding interfacial polymerization (IP) fabrication strategy for in-situ creation of asymmetric block copolymer (BCP) nanofilms with antifouling properties, greatly outperforming the conventional surface post-modification approaches. The resultant asymmetric BCP nanofilms with highly-dense, highly-hydrophilic polyethylene glycol (PEG) brushes, can be readily formed via a typical IP process of a double-hydrophilic BCP composed of an antifouling PEG block and a membrane-forming multiamine block. The asymmetric BCP nanofilms have been applied for efficient and sustainable natural water purification, demonstrating extraordinary antifouling capabilities accompanied with superior separation performance far beyond commercial polyamide nanofiltration membranes. The antifouling behaviors of BCP nanofilms derived from the combined effect of the hydration layer, electrostatic repulsion and steric hindrance were further elucidated by water flux and fouling resistance in combination with all-atom molecular dynamics simulation. This work opens up a new avenue for large-scale and low-cost creation of broad-spectrum, asymmetric membrane materials with diverse functional "defect-free" surfaces in real-world applications.

19.
Chemistry ; 29(38): e202300879, 2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37104095

RESUMO

Inspired by carbon monoxide dehydrogenase (CODH), mimicking its inner and outer spheres is a promising strategy in CO2 reduction catalyst design. However, artificial CODH-like catalysts are generally limited to the inner sphere effect and only applicable in organic solvents or for electrocatalysis. Herein, an aqueous CODH mimic with both inner and outer spheres for photocatalysis is reported. In this polymeric unimolecular catalyst, the inner sphere is composed of cobalt porphyrin with four appended amido groups and the outer sphere consists of four poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) arms. Upon visible light irradiation (λ >420 nm), the as-prepared catalyst exhibits a turnover number (TONCO ) of 1731.2 in the reduction of CO2 into CO, which is comparable to most reported molecular catalysts in aqueous solution. The mechanism studies indicate that, in this water-dispersible and structurally well-defined CODH mimic, the cobalt porphyrin core serves as the catalysis center and the amido groups function as hydrogen-bonding pillars helping to stabilize the CO2 adduct intermediate, whereas the PDMAEMA shell renders both water solubility and a CO2 reservoir through reversibly capturing of CO2 . The present work has clarified the significance of coordination sphere effects for improving the aqueous photocatalytic CO2 reduction performance of CODH mimics.


Assuntos
Mimetismo Molecular , Soluções , Catálise , Oxirredução , Dióxido de Carbono/química , Micelas
20.
Reprod Biomed Online ; : 103772, 2023 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-38749801

RESUMO

RESEARCH QUESTION: What is the role and mechanism of action of transcription factor AP-2 gamma (TFAP2C) in porcine early embryo development? DESIGN: TFAP2C siRNA were injected into porcine oocytes, which subsequently underwent IVF. Different stages of embryos were collected for RNA sequencing, quantitative polymerase chain reaction, immunofluorescence staining to explore the affects in gene expression and epigenetic modification. Porcine fetal fibroblasts were transfected with siRNA, and cells were collected for chromatin immunoprecipitation and dual luciferase reporter assays. RESULTS: The deficiency of TFAP2C led to disorders in early embryonic development; 1208 genes were downregulated and 792 genes were upregulated in TFAP2C knockdown (TFAP2C-KD) embryos. The expression of epigenetic modification enzymes KDM5B, SETD2 were significantly elevated in the TFAP2C-KD group (P < 0.001). Meanwhile, the modification levels of H3K4me3 and H3K4me2 were significantly decreased (P = 0.0021, P = 0.0029), and H3K36me3 and DNA methylation were significantly increased in TFAP2C-KD group (P = 0.0045, P = 0.0025). DNMT1 was mainly expressed in nuclei in the TFAP2C-KD group (P = 0.0103). In addition, TFAP2C could bind to the promoter region of SETD2, and the mutation of the TFAP2C binding site resulted in increased activity of SETD2 promoter (P < 0.001). CONCLUSIONS: The knockdown of TFAP2C affects early embryonic development by regulating histone modification and DNA methylation.

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