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1.
Acc Chem Res ; 56(12): 1469-1481, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37219046

RESUMO

ConspectusFor optical and electronic applications of supramolecular assemblies, control of the hierarchical structure from nano- to micro- and millimeter scale is crucial. Supramolecular chemistry controls intermolecular interactions to build up molecular components with sizes ranging from several to several hundreds of nanometers using bottom-up self-assembly process. However, extending the supramolecular approach up to a scale of several tens of micrometers to construct objects with precisely controlled size, morphology, and orientation is challenging. Especially for microphotonics applications such as optical resonators and lasers, integrated optical devices, and sensors, a precise design of a micrometer-scale object is required. In this Account, we review the recent progress on precise control of microstructures from π-conjugated organic molecules and polymers, which work as micro-photoemitters and are suitable for optical applications.After the introduction on the importance of the control of the hierarchical structures from molecular assembly, we review supramolecular methodology for assembling molecules and supramolecules to form microstructures such as spheres and polygons with precisely controlled morphology and molecular orientations. The resultant microstructures act as anisotropic emitters of circularly polarized luminescence. We report that synchronous crystallization of π-conjugated chiral cyclophanes forms concave hexagonal pyramidal microcrystals with homogeneous size, morphology, and orientation, which clearly paves the way for the precise control of skeletal crystallization under kinetic control. Furthermore, we show microcavity functions of the self-assembled micro-objects. The self-assembled π-conjugated polymer microspheres work as whispering gallery mode (WGM) optical resonators, where the photoluminescence exhibits sharp and periodic emission lines. The spherical resonators with molecular functions act as long-distance photon energy transporters, convertors, and full-color microlasers. Fabrication of microarrays with photoswitchable WGM microresonators by the surface self-assembly technique realizes optical memory with physically unclonable functions of WGM fingerprints. All-optical logic operations are demonstrated by arranging the WGM microresonators on synthetic and natural optical fibers, where the photoswitchable WGM microresonators act as a gate for light propagation via a cavity-mediated energy transfer cascade. Meanwhile, the sharp WGM emission line is appropriate for utilization as optical sensors for monitoring the mode shift and mode splitting. The resonant peaks sensitively respond to humidity change, absorption of volatile organic compounds, microairflow, and polymer decomposition by utilizing structurally flexible polymers, microporous polymers, nonvolatile liquid droplets, and natural biopolymers as media of the resonators. We further construct microcrystals from π-conjugated molecules with rods and rhombic plates, which act as WGM laser resonators with light-harvesting function. Our developments, precise design and control of organic/polymeric microstructures, form a bridge between nanometer-scale supramolecular chemistry and bulk materials and pave the way toward flexible micro-optics applications.

2.
J Am Chem Soc ; 145(25): 13920-13928, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37306612

RESUMO

Here, we report an anomalous pathway complexity in the supramolecular polymerization of a chiral monomer, which displays an unusual chiroptical feature that does not follow any of the known stereochemical rules such as "chiral self-sorting" and "majority rule". We newly developed a planar-chiral ferrocene-cored tetratopic pyridyl monomer FcL, which underwent AgBF4-mediated supramolecular polymerization to give nanotubes FcNTs composed of metal-organic nanorings FcNRs. Although FcNRs must be homochiral because of a strong geometrical constraint, FcNRs were formed even efficiently from racemic FcL and AgBF4. Detailed studies revealed the presence of two competing pathways for producing homochiral FcNRs as the constituents of FcNTs: (i) spontaneous cyclization of initially formed acyclic polymers -[FcL-Ag+]n- and (ii) template (FcNR)-assisted cyclization via a Ag+···Ag+ metallophilic interaction. The dominance of the two pathways changes depending on the %ee of chiral FcL. Namely, when the %ee of FcL is high, -[FcL-Ag+]n- must contain sufficiently long homochiral sequences that can be readily cyclized into FcNRs. Meanwhile, when the %ee of FcL is low, the homochiral sequences in -[FcL-Ag+]n- must be short and therefore are hardly eligible for spontaneous cyclization. Why were FcNRs formed? Even though the probability is very low, homochiral -[FcL-Ag+]n- can be statistically generated and undergo spontaneous cyclization to give FcNRs minutely. We found that FcNRs can be amplified by heterochirally templating their own synthesis using metallophilic interaction. Because of this stereochemical preference, the growth of FcNRs into FcNTs via the template-assisted mechanism occurs only when both (R,R)FcL and (S,S)FcL are present in the polymerization system.

3.
J Am Chem Soc ; 143(23): 8772-8779, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34085826

RESUMO

It has long been surmised that the circular polarization of luminescence (CPL) emitted by a chiral molecule or a molecular assembly should vary with the direction in which the photon is emitted. Despite its potential utility, this anisotropic CPL has not yet been demonstrated at the level of single molecules or supramolecular assemblies. Here we show that conjugated polymers bearing chiral side chains self-assemble into solid microspheres with a twisted bipolar interior, which are formed via liquid-liquid phase separation and subsequent condensation into a cholesteric lyotropic liquid crystalline mesophase. The resultant microspheres, when dispersed in methanol, exhibit CPL with a glum value as high as 0.23. The microspheres are mechanically robust enough to be handled with a microneedle under ambient conditions, allowing comprehensive examination of the angular anisotropy of CPL. The single microsphere is found to exhibit distinct angularly anisotropic birefringence and CPL with glum up to ∼0.5 in the equatorial plane, which is 2.5-fold greater than that along the polar axis. Such optically anisotropic solid materials are important for the application to next-generation microlight-emitting and visualizing devices as well as for fundamental optics studies of chiral light-matter interaction.

4.
Mol Genet Genomics ; 296(3): 705-717, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33772345

RESUMO

Cytoplasmic male sterility (CMS) observed in many plants leads defect in the production of functional pollen, while the expression of CMS is suppressed by a fertility restorer gene in the nuclear genome. Ogura CMS of radish is induced by a mitochondrial orf138, and a fertility restorer gene, Rfo, encodes a P-type PPR protein, ORF687, acting at the translational level. But, the exact function of ORF687 is still unclear. We found a Japanese variety showing male sterility even in the presence of Rfo. We examined the pollen fertility, Rfo expression, and orf138 mRNA in progenies of this variety. The progeny with Type H orf138 and Rfo showed male sterility when their orf138 mRNA was unprocessed within the coding region. By contrast, all progeny with Type A orf138 were fertile though orf138 mRNA remained unprocessed in the coding region, demonstrating that ORF687 functions on Type A but not on Type H. In silico analysis suggested a specific binding site of ORF687 in the coding region, not the 5' untranslated region estimated previously, of Type A. A single nucleotide substitution in the putative binding site diminishes affinity of ORF687 in Type H and is most likely the cause of the ineffectiveness of ORF687. Furthermore, fertility restoration by RNA processing at a novel site in some progeny plants indicated a new and the third fertility restorer gene, Rfs, for orf138. This study clarified that direct ORF687 binding to the coding region of orf138 is essential for fertility restoration by Rfo.


Assuntos
Proteínas de Arabidopsis/genética , Fertilidade/genética , Genes de Plantas/genética , Nucleotídeos/genética , Fases de Leitura Aberta/genética , Polimorfismo de Nucleotídeo Único/genética , Proteínas Quinases/genética , Raphanus/genética , Regiões 5' não Traduzidas/genética , Aminoácidos/genética , Sequência de Bases , Citoplasma/genética , Regulação da Expressão Gênica de Plantas/genética , Mitocôndrias/genética , Infertilidade das Plantas/genética , Proteínas de Plantas/genética , Pólen/genética , Processamento Pós-Transcricional do RNA/genética , RNA Mensageiro/genética
5.
Genome ; 64(12): 1081-1089, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34129801

RESUMO

The mitochondrial gene orf108, which is co-transcribed with atp1 and causes cytoplasmic male sterility in Brassica crops, is widely distributed across wild species and genera of Brassicaceae. However, to date, intraspecific variations in the presence of orf108 have not yet been studied, and the mechanisms underlying the wide distribution of the gene remain unclear. We analyzed the presence and sequence variations of orf108 in two wild species, Brassica maurorum and Moricandia arvensis. After polymerase chain reaction amplification of the 5' region of atp1 and the coding sequence of orf108, we determined the DNA sequences. Brassica maurorum and M. arvensis showed variations in the presence of orf108 or orf117 (orf108V117) both between and within accessions and were not fixed to the mitochondrial type with the male sterile genes. Sequencing of the amplicons showed that B. maurorum had orf108V117 instead of orf108. Sequencing also indicated mitochondrial heteroplasmy in the two species; in particular, in B. maurorum, one plant possessed both orf108 and orf108V117 sequences. These results suggest that substoichiometric shifting of mitochondrial genomes leads to the acquisition or loss of orf108. Furthermore, fertility restorer genes of the two species were involved in the processing of the mRNA of male sterility genes at different sites.


Assuntos
Brassica , Brassicaceae/genética , Genes de Plantas , Infertilidade das Plantas , Brassica/genética , Citoplasma , Infertilidade das Plantas/genética , RNA Mensageiro
6.
Breed Sci ; 70(5): 637-641, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33603561

RESUMO

In addition to Ogura cytoplasmic male sterility (CMS), which is used extensively for F1 hybrid seed production in Brassicaceae crops, two other CMS systems, NWB CMS and DCGMS, have also been identified. The causal gene for the latter two CMS systems has been identified as a novel chimeric gene, orf463. We previously reported that orf463 is specific to black radish cultivars and that it is present in line 'RS-5' of Raphanus raphanistrum; however, the orf463 sequence in 'RS-5' differed from that of black radish cultivars. Though, R. raphanistrum with an orf463 sequence identical to that found in black radish cultivars was recently identified. We therefore sought to determine whether the orf463 gene in line 'RS-5' induces CMS in radishes. We crossed 'RS-5' as a female parent with a cultivated radish, 'Uchiki-Gensuke', as a male parent, and examined the gross plant morphology and pollen fertility of the resulting progeny. The F2 population contained both male sterile plants and plants with black roots. The findings showed that R. raphanistrum contains two types of orf463 genes that induce CMS, and that the origin of black radishes could be attributed to R. raphanistrum having orf463 gene.

7.
Angew Chem Int Ed Engl ; 59(31): 12674-12679, 2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-32338404

RESUMO

Microcrystallites are promising minute mirrorless laser sources. A variety of luminescent organic compounds have been exploited along this line, but dendrimers have been inapplicable owing to their fragility and extremely poor crystallinity. Now, a dendrimer family that overcomes these difficulties is presented. First-, second-, and third-generation carbazole (Cz) dendrimers with a carbon-bridged oligo(phenylenevinylene) (COPV2) core (GnCOPV2, n=1-3) assemble to form microcrystals. The COPV2 cores align uni/bidirectionally in the crystals while the Cz units in G2- and G3COPV2 align omnidirectionally. The dendrons work as light-harvesting antennas that absorb non-polarized light and transfer it to the COPV2 core, from which a polarized luminescence radiates. Furthermore, these crystals act as laser resonators, where the lasing thresholds are strongly coupled with the crystal morphology and the orientation of COPV2, which is in contrast with the conventional amorphous dendrimers.

8.
Breed Sci ; 67(4): 357-362, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29085245

RESUMO

The complete sequence of the mitochondrial genome was determined for two cultivars of Brassica rapa. After determining the sequence of a Chinese cabbage variety, 'Oushou hakusai', the sequence of a mizuna variety, 'Chusei shiroguki sensuji kyomizuna', was mapped against the sequence of Chinese cabbage. The precise sequences where the two varieties demonstrated variation were ascertained by direct sequencing. It was found that the mitochondrial genomes of the two varieties are identical over 219,775 bp, with a single nucleotide polymorphism (SNP) between the genomes. Because B. rapa is the maternal species of an amphidiploid crop species, Brassica juncea, the distribution of the SNP was observed both in B. rapa and B. juncea. While the mizuna type SNP was restricted mainly to cultivars of mizuna (japonica group) in B. rapa, the mizuna type was widely distributed in B. juncea. The finding that the two Brassica species have these SNP types in common suggests that the nucleotide substitution occurred in wild B. rapa before both mitotypes were domesticated. It was further inferred that the interspecific hybridization between B. rapa and B. nigra took place twice and resulted in the two mitotypes of cultivated B. juncea.

9.
J Am Chem Soc ; 137(24): 7628-31, 2015 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-26053066

RESUMO

Coassembly of an achiral ferrocene-cored tetratopic pyridyl ligand (FcL) with AgBF4 in CH2Cl2/MeCN (7:3 v/v) containing chiral Bu4N(+) (+)- or (-)-menthylsulfate (MS*(-)) results in the formation of an "optically active" metal-organic nanotube (FcNT) composed of a C10-symmetric double-decker nanoring featuring 10 FcL units and 20 Ag(+) ions. The circular dichroism spectrum of FcNT along with its 2D X-ray diffraction (2D XRD) pattern indicates that the constituent metal-organic nanorings in FcNT stack one-handed helically on top of each other. A crystal structure of the dimeric double-decker model complex (Ag2(FcL')2) from a ditopic ferrocene ligand (FcL') and AgBF4 allowed for confirming the binding of MS*(-) onto the Ag(+) center of the complex. The results of detailed spectroscopic studies indicate that in its double-decker aromatic arrays, FcNT possibly possesses propeller-chiral twists in addition to the helically chiral structure, where the former is considerably more dynamic than the latter. Notably, both chiral structural motifs responded nonlinearly to an enantiomeric excess of MS*(-) (majority rule) though with no stereochemical influence on one another.

10.
Curr Genet ; 60(4): 277-84, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24916859

RESUMO

The complete mitochondrial genome sequences of Brassica species have provided insight into inter- and intraspecific variation of plant mitochondrial genomes. However, the size of mitochondrial genome sequenced for Brassica oleracea hitherto does not match to its physical mapping data. This fact led us to investigate B. oleracea mitochondrial genome in detail. Here we report novel B. oleracea mitochondrial genome, derived from var. capitata, a cabbage cultivar ''Fujiwase''. The genome was assembled into a 219,952-bp circular sequence that is comparable to the mitochondrial genomes of other Brassica species (ca. 220-232 kb). This genome contained 34 protein-coding genes, 3 rRNA genes and 17 tRNA genes. Due to absence of a large repeat (140 kb), the mitochondrial genome of ''Fujiwase'' is clearly smaller than the previously reported mitochondrial genome of B. oleracea accession ''08C717'' (360 kb). In both mitotypes, all genes were identical, except cox2-2, which was present only in the Fujiwase type. At least two rearrangement events via large and small repeat sequences have contributed to the structural differences between the two mitotypes. PCR-based marker analysis revealed that the Fujiwase type is predominant, whereas the 08C717 type coexists at low frequency in all B. oleracea cultivars examined. Intraspecific variations in the mitochondrial genome in B. oleracea may occur because of heteroplasmy, coexistence of different mitotypes within an individual, and substoichiometric shifting. Our data indicate that the Fujiwase-type genome should be used as the representative genome of B. oleracea.


Assuntos
Brassica/genética , Genoma Mitocondrial/genética , Genoma de Planta/genética , Mitocôndrias/genética , DNA Mitocondrial/química , DNA Mitocondrial/genética , DNA de Plantas/química , DNA de Plantas/genética , Análise de Sequência de DNA
11.
Genome ; 57(11-12): 577-82, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25767903

RESUMO

Crop species of Brassica (Brassicaceae) consist of three monogenomic species and three amphidiploid species resulting from interspecific hybridizations among them. Until now, mitochondrial genome sequences were available for only five of these species. We sequenced the mitochondrial genome of the sixth species, Brassica nigra (nuclear genome constitution BB), and compared it with those of Brassica oleracea (CC) and Brassica carinata (BBCC). The genome was assembled into a 232 145 bp circular sequence that is slightly larger than that of B. oleracea (219 952 bp). The genome of B. nigra contained 33 protein-coding genes, 3 rRNA genes, and 17 tRNA genes. The cox2-2 gene present in B. oleracea was absent in B. nigra. Although the nucleotide sequences of 52 genes were identical between B. nigra and B. carinata, the second exon of rps3 showed differences including an insertion/deletion (indel) and nucleotide substitutions. A PCR test to detect the indel revealed intraspecific variation in rps3, and in one line of B. nigra it amplified a DNA fragment of the size expected for B. carinata. In addition, the B. carinata lines tested here produced DNA fragments of the size expected for B. nigra. The results indicate that at least two mitotypes of B. nigra were present in the maternal parents of B. carinata.


Assuntos
Genoma Mitocondrial , Mostardeira/genética , Brassica/genética , Éxons , Genes Mitocondriais , Variação Genética , Análise de Sequência de DNA
12.
Breed Sci ; 64(1): 38-47, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24987289

RESUMO

Brassicaceae crops display strong hybrid vigor, and have long been subject to F1 hybrid breeding. Because the most reliable system of F1 seed production is based on cytoplasmic male sterility (CMS), various types of CMS have been developed and adopted in practice to breed Brassicaceae oil seed and vegetable crops. CMS is a maternally inherited trait encoded in the mitochondrial genome, and the male sterile phenotype arises as a result of interaction of a mitochondrial CMS gene and a nuclear fertility restoring (Rf) gene. Therefore, CMS has been intensively investigated for gaining basic insights into molecular aspects of nuclear-mitochondrial genome interactions and for practical applications in plant breeding. Several CMS genes have been identified by molecular genetic studies, including Ogura CMS from Japanese radish, which is the most extensively studied and most widely used. In this review, we discuss Ogura CMS, and other CMS systems, and the causal mitochondrial genes for CMS. Studies on nuclear Rf genes and the cytoplasmic effects of alien cytoplasm on general crop performance are also reviewed. Finally, some of the unresolved questions about CMS are highlighted.

13.
ACS Appl Bio Mater ; 7(3): 1513-1525, 2024 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-38354359

RESUMO

Skin is the body barrier that constrains the infiltration of particles and exogenous aggression, in which the hair follicle plays an important role. Recent studies have shown that small particles can penetrate the skin barrier and reach the hair follicle, making them a potential avenue for delivering hair growth-related substances. Interestingly, keratin-based microspheres are widely used as drug delivery carriers in various fields. In this current study, we pursue the effect of newly synthesized 3D spherical keratin particles on inducing hair growth in C57BL/6 male mice and in human hair follicle dermal papilla cells. The microspheres were created from partially sulfonated, water-soluble keratin. The keratin microspheres swelled in water to form spherical gels, which were used for further experiments. Following topical application for a period of 20 days, we observed a regrowth of hair in the previously depleted area on the dorsal part of the mice in the keratin microsphere group. This observation was accompanied by the regulation of hair-growth-related pathways as well as changes in markers associated with epidermal cells, keratin, and collagen. Interestingly, microsphere keratin treatment enhanced the cell proliferation and the expression of hair growth markers in dermal papilla cells. Based on our data, we propose that 3D spherical keratin has the potential to specifically target hair follicle growth and can be employed as a carrier for promoting hair growth-related agents.


Assuntos
Cabelo , Queratinas , Masculino , Camundongos , Humanos , Animais , Queratinas/metabolismo , Queratinas/farmacologia , Microesferas , Camundongos Endogâmicos C57BL , Cabelo/metabolismo , Água
14.
Chem Commun (Camb) ; 60(59): 7634-7637, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-38958669

RESUMO

A microsphere, assembled from a chiral π-conjugated polymer with narrow polydispersity, features a well-organized twisted-bipolar structure and exhibits highly biased circularly polarized luminescence (CPL). The CPL emitted toward the equatorial direction is 61-fold greater than that emitted along the zenith direction, which is the highest anisotropy among existing microscopic CPL emitters.

15.
Genome ; 56(4): 187-93, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23706071

RESUMO

In wheat (Triticum) and Aegilops, chloroplast and mitochondrial genomes have been studied for over three decades to clarify the phylogenetic relationships among species, and most of the maternal lineages of polyploid species have been clarified. Mitochondrial genomes of Emmer (tetraploid with nuclear genome AABB) and Dinkel (hexaploid with AABBDD) wheat are classified into two different types, VIIa and VIIb, by the presence-absence of the third largest HindIII fragment (named H3) in the mitochondrial DNA. Although the mitochondrial genome in the genera often provides useful information to clarify the phylogenetic relationship among closely related species, the phylogenetic significance of this dimorphism has yet not been clarified. In this study, to facilitate analysis using a large number of accessions, a sequence characterized amplified region (SCAR) marker that distinguishes the type VIIb mitochondrial genome from type VIIa was first developed. Mitochondrial genome type was determined for each of 30 accessions of wild and cultivated Emmer wheat and 25 accessions of Dinkel wheat. The mitochondrial genome type for each accession was compared with the plastogroup that had been determined using chloroplast microsatellite markers. Unexpectedly, the distribution of mitochondrial genome type was not in accordance with that of the plastogroups, suggesting occasional paternal leakage of either the mitochondrial or chloroplast genome during speciation and differentiation of Emmer and Dinkel wheat. An alternative possibility that substoichiometric shifting is involved in the observed dimorphism of the mitochondrial genome is also discussed.


Assuntos
Evolução Molecular , Genoma de Cloroplastos , Genoma Mitocondrial , Desequilíbrio de Ligação , Triticum/genética , Marcadores Genéticos , Especiação Genética , Genoma de Planta , Repetições de Microssatélites , Filogenia , Ploidias
16.
Chem Commun (Camb) ; 59(11): 1477-1480, 2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36651843

RESUMO

Optical resonators work as precise physical and chemical sensors. Here, we assemble a whispering gallery mode resonator from a natural polymer, fibroin protein, and successfully observe its catalytic degradation reaction as a spectral shift. This methodology will contribute to the precise in situ observation of biological reactions by optical microscopy.


Assuntos
Microscopia , Polímeros , Hidrólise , Urinálise
17.
Nanoscale ; 15(47): 19062-19068, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-37987533

RESUMO

Thermally tolerant polymer optical resonators are fabricated from a stereocomplex of poly(L-lactic acid) and poly(D-lactic acid) through the oil-in-water miniemulsion method. The thermal stability of the microspheres of the stereocomplex poly(lactic acid) (SC-PLA) is superior to that of the homochiral poly(lactic acid) (HC-PLA). As a result of the high thermal stability, the optical resonator properties of the SC-PLA microspheres are preserved at an elevated temperature of up to 230 °C, which is 70 °C higher than that of microspheres formed from HC-PLA.

18.
BMC Genomics ; 13: 352, 2012 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-22846596

RESUMO

BACKGROUND: Plant mitochondrial genome has unique features such as large size, frequent recombination and incorporation of foreign DNA. Cytoplasmic male sterility (CMS) is caused by rearrangement of the mitochondrial genome, and a novel chimeric open reading frame (ORF) created by shuffling of endogenous sequences is often responsible for CMS. The Ogura-type male-sterile cytoplasm is one of the most extensively studied cytoplasms in Brassicaceae. Although the gene orf138 has been isolated as a determinant of Ogura-type CMS, no homologous sequence to orf138 has been found in public databases. Therefore, how orf138 sequence was created is a mystery. In this study, we determined the complete nucleotide sequence of two radish mitochondrial genomes, namely, Ogura- and normal-type genomes, and analyzed them to reveal the origin of the gene orf138. RESULTS: Ogura- and normal-type mitochondrial genomes were assembled to 258,426-bp and 244,036-bp circular sequences, respectively. Normal-type mitochondrial genome contained 33 protein-coding and three rRNA genes, which are well conserved with the reported mitochondrial genome of rapeseed. Ogura-type genomes contained same genes and additional atp9. As for tRNA, normal-type contained 17 tRNAs, while Ogura-type contained 17 tRNAs and one additional trnfM. The gene orf138 was specific to Ogura-type mitochondrial genome, and no sequence homologous to it was found in normal-type genome. Comparative analysis of the two genomes revealed that radish mitochondrial genome consists of 11 syntenic regions (length >3 kb, similarity >99.9%). It was shown that short repeats and overlapped repeats present in the edge of syntenic regions were involved in recombination events during evolution to interconvert two types of mitochondrial genome. Ogura-type mitochondrial genome has four unique regions (2,803 bp, 1,601 bp, 451 bp and 15,255 bp in size) that are non-syntenic to normal-type genome, and the gene orf138 was found to be located at the edge of the largest unique region. Blast analysis performed to assign the unique regions showed that about 80% of the region was covered by short homologous sequences to the mitochondrial sequences of normal-type radish or other reported Brassicaceae species, although no homology was found for the remaining 20% of sequences. CONCLUSIONS: Ogura-type mitochondrial genome was highly rearranged compared with the normal-type genome by recombination through one large repeat and multiple short repeats. The rearrangement has produced four unique regions in Ogura-type mitochondrial genome, and most of the unique regions are composed of known Brassicaceae mitochondrial sequences. This suggests that the regions unique to the Ogura-type genome were generated by integration and shuffling of pre-existing mitochondrial sequences during the evolution of Brassicaceae, and novel genes such as orf138 could have been created by the shuffling process of mitochondrial genome.


Assuntos
Citoplasma/metabolismo , DNA Mitocondrial/genética , Genoma Mitocondrial/genética , Infertilidade das Plantas/genética , Raphanus/metabolismo , Raphanus/fisiologia , Raphanus/genética
19.
Chem Commun (Camb) ; 58(85): 11887-11897, 2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36193786

RESUMO

Organic molecules favour dense packing so that they can maximise the enthalpic gain upon solidification. Multidentate organic molecules that can form reticular bonding networks have been considered essential to overcome this tendency and assemble the molecules in a porous manner. Meanwhile, contrary to this understanding, a few organic molecules have been found to form porous molecular crystals by simply stacking with each other via van der Waals forces or analogous very weak noncovalent interactions. Although the porous molecular crystals were relatively rare in the 2000s due to the difficulty in the synthesis, their number has increased in the last decade, and their functional uniqueness has been unveiled eventually. This article reviews the recent advances in such functional porous molecular crystals. Particularly, thermal stability, processability, structural dynamicity, reactivity, and self-healing ability are highlighted. In addition, fundamental principles behind their functionalities, including the history, energetics, and the effect of crystallization solvent, are also reviewed.


Assuntos
Porosidade , Cristalização , Termodinâmica , Solventes/química
20.
Science ; 377(6606): 673-678, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35926016

RESUMO

Skeletal or concave polyhedral crystals appear in a variety of synthetic processes and natural environments. However, their morphology, size, and orientation are difficult to control because of their highly kinetic growth character. We report a methodology to achieve synchronous, uniaxial, and stepwise growth of micrometer-scale skeletal single crystals from planar-chiral double-decker molecules. Upon drop-casting of a heated ethanol solution onto a quartz substrate, the molecules spontaneously assemble into standing vessel-shaped single crystals uniaxially and synchronously over the wide area of the substrate, with small size polydispersity. The crystal edge is active even after consumption of the molecules and resumes stereoselective growth with successive feeding. The resultant morphology can be packed into polycyclic aromatic hydrocarbon-like microarchitectures and behaves as a microscopic container.

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