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1.
Cell ; 152(3): 406-16, 2013 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-23374338

RESUMO

Ciliates are an ancient and diverse group of microbial eukaryotes that have emerged as powerful models for RNA-mediated epigenetic inheritance. They possess extensive sets of both tiny and long noncoding RNAs that, together with a suite of proteins that includes transposases, orchestrate a broad cascade of genome rearrangements during somatic nuclear development. This Review emphasizes three important themes: the remarkable role of RNA in shaping genome structure, recent discoveries that unify many deeply diverged ciliate genetic systems, and a surprising evolutionary "sign change" in the role of small RNAs between major species groups.


Assuntos
Evolução Biológica , Cilióforos/genética , Instabilidade Genômica , RNA de Protozoário/genética , RNA não Traduzido/genética , Genoma de Protozoário , RNA Longo não Codificante/genética
2.
Mol Cell ; 78(2): 289-302.e6, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32302541

RESUMO

Microprocessor initiates the processing of microRNAs (miRNAs) from the hairpin regions of primary transcripts (pri-miRNAs). Pri-miRNAs often contain multiple miRNA hairpins, and this clustered arrangement can assist in the processing of otherwise defective hairpins. We find that miR-451, which derives from a hairpin with a suboptimal terminal loop and a suboptimal stem length, accumulates to 40-fold higher levels when clustered with a helper hairpin. This phenomenon tolerates changes in hairpin order, linker lengths, and the identities of the helper hairpin, the recipient hairpin, the linker-sequence, and the RNA polymerase that transcribes the hairpins. It can act reciprocally and need not occur co-transcriptionally. It requires Microprocessor recognition of the helper hairpin and linkage of the two hairpins, yet predominantly manifests after helper-hairpin processing. It also requires enhancer of rudimentary homolog (ERH), which copurifies with Microprocessor and can dimerize and interact with other proteins that can dimerize, suggesting a model in which one Microprocessor recruits another Microprocessor.


Assuntos
Proteínas de Ciclo Celular/genética , MicroRNAs/genética , RNA Polimerase III/genética , Fatores de Transcrição/genética , RNA Polimerases Dirigidas por DNA/genética , Regulação da Expressão Gênica/genética , Humanos , Conformação de Ácido Nucleico , Processamento Pós-Transcricional do RNA/genética , Proteínas de Ligação a RNA/genética , Sequências Reguladoras de Ácido Nucleico/genética , Transcrição Gênica
3.
Cell ; 151(6): 1243-55, 2012 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-23217708

RESUMO

Genome duality in ciliated protozoa offers a unique system to showcase their epigenome as a model of inheritance. In Oxytricha, the somatic genome is responsible for vegetative growth, whereas the germline contributes DNA to the next sexual generation. Somatic nuclear development removes all transposons and other so-called "junk" DNA, which comprise ~95% of the germline. We demonstrate that Piwi-interacting small RNAs (piRNAs) from the maternal nucleus can specify genomic regions for retention in this process. Oxytricha piRNAs map primarily to the somatic genome, representing the ~5% of the germline that is retained. Furthermore, injection of synthetic piRNAs corresponding to normally deleted regions leads to their retention in later generations. Our findings highlight small RNAs as powerful transgenerational carriers of epigenetic information for genome programming.


Assuntos
Conjugação Genética , Genoma de Protozoário , Oxytricha/citologia , Oxytricha/genética , RNA de Protozoário/genética , RNA Interferente Pequeno/genética , Sequência de Aminoácidos , Sequência de Bases , Rearranjo Gênico , Macronúcleo/genética , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência
4.
Genome Res ; 33(3): 463-477, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-37310928

RESUMO

Structural variations (SVs) are a major contributor to genetic diversity and phenotypic variations, but their prevalence and functions in domestic animals are largely unexplored. Here we generated high-quality genome assemblies for 15 individuals from genetically diverse sheep breeds using Pacific Biosciences (PacBio) high-fidelity sequencing, discovering 130.3 Mb nonreference sequences, from which 588 genes were annotated. A total of 149,158 biallelic insertions/deletions, 6531 divergent alleles, and 14,707 multiallelic variations with precise breakpoints were discovered. The SV spectrum is characterized by an excess of derived insertions compared to deletions (94,422 vs. 33,571), suggesting recent active LINE expansions in sheep. Nearly half of the SVs display low to moderate linkage disequilibrium with surrounding single-nucleotide polymorphisms (SNPs) and most SVs cannot be tagged by SNP probes from the widely used ovine 50K SNP chip. We identified 865 population-stratified SVs including 122 SVs possibly derived in the domestication process among 690 individuals from sheep breeds worldwide. A novel 168-bp insertion in the 5' untranslated region (5' UTR) of HOXB13 is found at high frequency in long-tailed sheep. Further genome-wide association study and gene expression analyses suggest that this mutation is causative for the long-tail trait. In summary, we have developed a panel of high-quality de novo assemblies and present a catalog of structural variations in sheep. Our data capture abundant candidate functional variations that were previously unexplored and provide a fundamental resource for understanding trait biology in sheep.


Assuntos
Estudo de Associação Genômica Ampla , Cauda , Animais , Ovinos/genética , Regiões 5' não Traduzidas , Alelos , Fenótipo
5.
Glob Chang Biol ; 29(2): 391-403, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36203244

RESUMO

Approximately half of the global annual production of wastewater is released untreated into aquatic environments, which results in worldwide organic matter pollution in urban rivers, especially in highly populated developing countries. Nonetheless, information on microbial community assembly and assembly-driving processes in organic matter-polluted urban rivers remains elusive. In this study, a field study based on water and sediment samples collected from 200 organic matter-polluted urban rivers of 82 cities in China and Indonesia is combined with laboratory water-sediment column experiments. Our findings demonstrate a unique microbiome in these urban rivers. Among the community assembly-regulating factors, both organic matter and geographic conditions play major roles in determining prokaryotic and eukaryotic community assemblies, especially regarding the critical role of organic matter in regulating taxonomic composition. Using a dissimilarity-overlap approach, we found universality in the dynamics of water and sediment community assembly in organic matter-polluted urban rivers, which is distinctively different from patterns in eutrophic and oligotrophic waters. The prokaryotic and eukaryotic communities are dominated by deterministic and stochastic processes, respectively. Interestingly, water prokaryotic communities showed a three-phase cyclic succession of the community assembly process before, during, and after organic matter pollution. Our study provides the first large-scale and comprehensive insight into the prokaryotic and eukaryotic community assembly in organic matter-polluted urban rivers and supports their future sustainable management.


Assuntos
Microbiota , Rios , Cidades , Água , China
6.
Mol Cell ; 60(1): 131-45, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26412306

RESUMO

MicroRNAs (miRNAs) are small regulatory RNAs processed from stem-loop regions of primary transcripts (pri-miRNAs), with the choice of stem loops for initial processing largely determining what becomes a miRNA. To identify sequence and structural features influencing this choice, we determined cleavage efficiencies of >50,000 variants of three human pri-miRNAs, focusing on the regions intractable to previous high-throughput analyses. Our analyses revealed a mismatched motif in the basal stem region, a preference for maintaining or improving base pairing throughout the remainder of the stem, and a narrow stem-length preference of 35 ± 1 base pairs. Incorporating these features with previously identified features, including three primary-sequence motifs, yielded a unifying model defining mammalian pri-miRNAs in which motifs help orient processing and increase efficiency, with the presence of more motifs compensating for structural defects. This model enables generation of artificial pri-miRNAs, designed de novo, without reference to any natural sequence yet processed more efficiently than natural pri-miRNAs.


Assuntos
Biologia Computacional/métodos , MicroRNAs/metabolismo , Precursores de RNA/química , RNA Helicases DEAD-box/metabolismo , Células HEK293 , Humanos , Modelos Moleculares , Conformação de Ácido Nucleico , Precursores de RNA/metabolismo , Processamento Pós-Transcricional do RNA , Ribonuclease III/metabolismo
7.
Environ Sci Technol ; 55(14): 9579-9590, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-33852286

RESUMO

Surface sediments of polluted urban rivers can be a reservoir of hydrophobic persistent organic pollutants (POPs). In this study, we comprehensively assessed the contamination of two groups of POPs, that is, polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), in 173 black-odorous urban rivers in China. Spatial distribution of PCBs and PBDEs showed similar patterns but very different contamination levels in surface sediments, that is, average concentrations of 10.73 and 401.16 ng/g dw for the ∑PCBs and ∑PBDEs, respectively. Tetra-/di-CBs and deca-BDE are major PCBs and PBDEs and accounted for 59.11 and 95.11 wt % of the ∑PCBs and ∑PBDEs, respectively. Compared with the persistence of PBDEs, the EF changes of chiral PCBs together with previous cultivation evidence indicated indigenous bioconversion of PCBs in black-odorous urban rivers, particularly the involvement of uncharacterized Dehalococcoidia in PCB dechlorination. Major PCB sources (and their relative contributions) included pigment/painting (25.36%), e-waste (22.92%), metallurgical industry (13.25%), and e-waste/biological degradation process (10.95%). A risk assessment indicated that exposure of resident organisms in urban river sediments to deca-/penta-BDEs could pose a high ecological risk. This study provides the first insight into the contamination, conversion and ecological risk of PCBs and PBDEs in nationwide polluted urban rivers in China.


Assuntos
Bifenilos Policlorados , Poluentes Químicos da Água , China , Monitoramento Ambiental , Sedimentos Geológicos , Éteres Difenil Halogenados/análise , Bifenilos Policlorados/análise , Rios , Poluentes Químicos da Água/análise
8.
Genet Sel Evol ; 53(1): 74, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34507524

RESUMO

BACKGROUND: Goat, one of the first domesticated livestock, is a worldwide important species both culturally and economically. The current goat reference genome, known as ARS1, is reported as the first nonhuman genome assembly using 69× PacBio sequencing. However, ARS1 suffers from incomplete X chromosome and highly fragmented Y chromosome scaffolds. RESULTS: Here, we present a very high-quality de novo genome assembly, Saanen_v1, from a male Saanen dairy goat, with the first goat Y chromosome scaffold based on 117× PacBio long-read sequencing and 118× Hi-C data. Saanen_v1 displays a high level of completeness thanks to the presence of centromeric and telomeric repeats at the proximal and distal ends of two-thirds of the autosomes, and a much reduced number of gaps (169 vs. 773). The completeness and accuracy of the Saanen_v1 genome assembly are also evidenced by more assembled sequences on the chromosomes (2.63 Gb for Saanen_v1 vs. 2.58 Gb for ARS1), a slightly increased mapping ratio for transcriptomic data, and more genes anchored to chromosomes. The eight putative large assembly errors (1 to ~ 7 Mb each) found in ARS1 were amended, and for the first time, the substitution rate of this ruminant Y chromosome was estimated. Furthermore, sequence improvement in Saanen_v1, compared with ARS1, enables us to assign the likely correct positions for 4.4% of the single nucleotide polymorphism (SNP) probes in the widely used GoatSNP50 chip. CONCLUSIONS: The updated goat genome assembly including both sex chromosomes (X and Y) and the autosomes with high-resolution quality will serve as a valuable resource for goat genetic research and applications.


Assuntos
Genoma/genética , Genômica , Cabras/genética , Animais , Cromossomos de Mamíferos/genética , Indústria de Laticínios , Masculino , Polimorfismo de Nucleotídeo Único
9.
Biomacromolecules ; 21(6): 2176-2186, 2020 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-32286801

RESUMO

Many biological high-performance composites, such as bone, antler, and crustacean cuticles, are composed of densely mineralized and ordered nanofiber materials. The mimicry of even simplistic bioinspired structures, i.e., of densely and homogeneously mineralized nanofibrillar materials with controllable mechanical performance, continues to be a grand challenge. Here, using alkaline phosphatase as an enzymatic catalyst, we demonstrate the dense, homogeneous, and spatially controlled mineralization of calcium phosphate nanostructures within networks of anionically charged cellulose nanofibrils (CNFs) and cationically charged chitin nanofibrils (ChNFs)-both emerging biobased nanoscale building blocks for sustainable high-performance materials design. Our study reveals that anionic CNFs lead to a more homogeneous nanoscale mineralization with very high mineral contents up to ca. 70 wt % with a transition from amorphous to crystalline deposits, while cationic ChNFs yield rod-like crystalline morphologies. The bone-inspired CNF bulk films exhibit a significantly increased stiffness, maintain good flexibility and translucency, and have a significant gain in wet state mechanical properties. The mechanical properties can be tuned both by the enzyme concentration and the mineralization time. Moreover, we also show a spatial control of the mineralization using kinetically controlled substrate uptake in a dialysis reactor, and by spatially selectively incorporating the enzyme into 2D printed filament patterns. The strategy highlights possibilities for spatial encoding of enzymes in tailored structures and patterns and programmed mineralization processes, promoting the potential application of mineralized CNF biomaterials with complex gradients for bone substitutes and tissue regeneration in general.


Assuntos
Materiais Biomiméticos , Nanofibras , Biomimética , Celulose , Diálise Renal
10.
Environ Sci Technol ; 54(14): 8791-8800, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32551541

RESUMO

Polluted urban river sediments could be a sink of persistent and toxic polychlorinated biphenyls (PCBs) in urban areas and provide desired growth niches for organohalide-respiring bacteria (OHRB). In this study, microcosms were set up with surface sediments of nationwide polluted urban rivers in China, of which 164 cultures could dechlorinate tetrachloroethene (PCE) to dichloroethenes (DCEs) and to vinyl chloride and/or ethene. Further in vivo tests showed extensive PCB dechlorination with different pathways in 135 PCE pregrown cultures. Taking reductive dechlorination of PCB180 (2345-245-CB) as an example, 121 and 14 cultures preferentially removed flanked para- and meta-chlorines, respectively. Strikingly, all in vitro assays with the 135 PCE pregrown cultures showed identical PCB dechlorination pathways with their living cultures, implying the involvement of bifunctional reductive dehalogenases (RDases) to dechlorinate both PCBs and PCE. Further 16S rRNA and RDase gene-based analyses, together with enantioselective dechlorination of chiral PCBs, suggested that Dehalococcoides and Dehalogenimonas in the 135 cultures largely employed distinctively different novel bifunctional RDases to catalyze PCB/PCE dechlorination. Quantitative assessment of the community assembly process with the modified stochasticity ratio (MST) indicated three different stages in enrichment of OHRB. The second stage, as the only one controlled by stochastic processes (MST > 0.5), required extra attention in monitoring community successional patterns to minimize stochastic variance for enriching the PCB/PCE-dechlorinating OHRB.


Assuntos
Chloroflexi , Bifenilos Policlorados , Tetracloroetileno , Bactérias , Biodegradação Ambiental , China , Chloroflexi/genética , RNA Ribossômico 16S , Rios
11.
J Am Chem Soc ; 140(51): 17932-17944, 2018 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-30477299

RESUMO

Aromatic donor-acceptor interactions are of high importance in supramolecular chemistry, materials science and biology. Compared to other noncovalent interactions, such as hydrogen bonding, the binding is often weak. Here we show that strong donor-acceptor interactions between planar aromatics with binding free energies down to -10.1 kcal mol-1 and association constants of up to 2.34 × 107 L mol-1 for 1:1 complexes can be realized using cyclic trinuclear complexes of gold(I) with pyridinate, imidazolate, or carbeniate ligands. Data were obtained through NMR and UV/vis absorption spectroscopic studies and supported by quantum chemical calculations for a variety of acceptors. By using a specifically designed bridged naphthalene diimide-based acceptor with only one binding site, we furthermore show that a 1:2 (donor:acceptor) binding model is best suited to quantify the donor and acceptor/complex equilibrium. Scanning electron microscopy on selected donor-acceptor pairs shows crystalline supramolecular assemblies. We anticipate this study to be relevant for the future design of supramolecular systems and chemical sensors and the determination of binding energies between planar donors and acceptors.

12.
Biomacromolecules ; 18(6): 1866-1873, 2017 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-28440631

RESUMO

We investigated how a genetically engineered resilin fusion protein modifies cellulose surfaces. We characterized the pH-responsive behavior of a resilin-like polypeptide (RLP) having terminal cellulose binding modules (CBM) and showed its binding to cellulose nanofibrils (CNF). Characterization of the resilin fusion protein at different pHs revealed substantial conformational changes of the protein, which were observed as swelling and contraction of the protein layer bound to the nanocellulose surface. In addition, we showed that employment of the modified resilin in cellulose hydrogel and nanopaper increased their modulus of stiffness through a cross-linking effect.


Assuntos
Materiais Biocompatíveis/química , Celulose/química , Proteínas de Insetos/química , Nanoestruturas/química , Proteínas Recombinantes de Fusão/química , Sequência de Aminoácidos , Clonagem Molecular , Módulo de Elasticidade , Elasticidade , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Concentração de Íons de Hidrogênio , Proteínas de Insetos/biossíntese , Proteínas de Insetos/genética , Ligação Proteica , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Trichoderma/genética , Trichoderma/metabolismo
13.
Biomacromolecules ; 17(4): 1458-65, 2016 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-26907991

RESUMO

Native cellulose nanocrystals (CNCs) are valuable high quality materials with potential for many applications including the manufacture of high performance materials. In this work, a relatively effortless procedure was introduced for the production of CNCs, which gives a nearly 100% yield of crystalline cellulose. However, the processing of the native CNCs is hindered by the difficulty in dispersing them in water due to the absence of surface charges. To overcome these difficulties, we have developed a one-step procedure for dispersion and functionalization of CNCs with tailored cellulose binding proteins. The process is also applicable for polysaccharides. The tailored cellulose binding proteins are very efficient for the dispersion of CNCs due to the selective interaction with cellulose, and only small fraction of proteins (5-10 wt %, corresponds to about 3 µmol g(-1)) could stabilize the CNC suspension. Xyloglucan (XG) enhanced the CNC dispersion above a fraction of 10 wt %. For CNC suspension dispersed with carboxylmethyl cellulose (CMC) we observed the most long-lasting stability, up to 1 month. The cellulose binding proteins could not only enhance the dispersion of the CNCs, but also functionalize the surface. This we demonstrated by attaching gold nanoparticles (GNPs) to the proteins, thus, forming a monolayer of GNPs on the CNC surface. Cryo transmission electron microscopy (Cryo-TEM) imaging confirmed the attachment of the GNPs to CNC solution conditions.


Assuntos
Celulose/química , Celulose/síntese química , Nanopartículas/química , Polissacarídeos/química , Proteínas/química , Microscopia Crioeletrônica , Glucanos/química , Ouro/química , Microscopia de Força Atômica , Xilanos/química
14.
Anal Methods ; 16(25): 4074-4082, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38855900

RESUMO

Prothioconazole and its metabolite are considered a potential threat to human health and environmental safety. Thus, the development of a sensitive and rapid detection method for prothioconazole is crucial to ensure the safety of agricultural products. In this study, a new hapten of prothioconazole was designed and synthesized, and a selective polyclonal antibody with high affinity against prothioconazole was produced, which was obtained from immunized New Zealand white rabbits. Based on the polyclonal antibody, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and indirect competitive chemiluminescence enzyme immunoassay (ic-CLEIA) were developed for detecting prothioconazole pesticides. Under optimized experimental conditions, the limit of quantification (LOQ) values for ic-CLEIA and ic-ELISA were 1.8 and 10.7 ng mL-1, respectively. The results demonstrated that the sensitivity (LOQ) achieved by ic-CLEIA was more than five times higher compared to that obtained with ic-ELISA. In addition, the recoveries obtained by adding standard prothioconazole to wheat grain, soybean, and pond water samples were in the range of 81.9 to 104.7% for ic-ELISA and 89.0 to 118.0% for ic-CLEIA.


Assuntos
Anticorpos , Ensaio de Imunoadsorção Enzimática , Glycine max , Triazóis , Triticum , Animais , Ensaio de Imunoadsorção Enzimática/métodos , Triazóis/análise , Triazóis/química , Triticum/química , Glycine max/química , Coelhos , Anticorpos/imunologia , Anticorpos/química , Poluentes Químicos da Água/análise , Grão Comestível/química , Água Doce/análise , Limite de Detecção , Medições Luminescentes/métodos , Fungicidas Industriais/análise , Haptenos/química , Haptenos/imunologia
15.
Polymers (Basel) ; 16(11)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38891529

RESUMO

We developed a highly sensitive solid-state sensor for mercury detection by stabilizing red-sub-nanometric fluorescent gold nanoclusters (AuNC, 0.9 ± 0.1 nm diameter) with bovine serum albumin in a matrix composed of cellulose nanofibrils (CNF) (BSA-AuNC/CNF). The main morphological and optical features of the system were investigated via atomic force/transmission electron microscopy and UV-Vis/fluorescence spectroscopy. The hybrid film (off-white and highly transparent) showed strong photoluminescene under UV irradiation. The latter is assigned to the AuNC, which also increase the ductility of the emitting film, which was demonstrated for high sensitivity Hg2+ detection. When used as a sensor system, following AuNC printing on CNF hybrid films, a limit of detection <10 nM was confirmed. What is more, nanocellulose films have a high pore structure and selective separation properties, showcasing a wide range of potential applications in many fields such as water treatment and oil-water separation.

16.
Food Chem ; 447: 138916, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-38461723

RESUMO

As one of the most abundant plant polyphenols in the human diet, (-)-epicatechin (EC) can improve insulin sensitivity and regulate glucose homeostasis. However, the primary mechanisms involved in EC anti-T2DM benefits remain unclear. The present study explored the effects of EC on the gut microbiota and liver transcriptome in type 2 diabetes mellitus (T2DM) Goto-Kakizaki rats for the first time. The findings showed that EC protected glucose homeostasis, alleviated systemic oxidative stress, relieved liver damage, and increased serum insulin. Further investigation showed that EC reshaped gut microbiota structure, including inhibiting the proliferation of lipopolysaccharide (LPS)-producing bacteria and reducing serum LPS. In addition, transcriptome analysis revealed that the insulin signaling pathway may be the core pathway of the EC anti-T2DM effect. Therefore, EC may modulate the gut microbiota and liver insulin signaling pathways by the gut-liver axis to alleviate T2DM. As a diet supplement, EC has promising potential in T2DM prevention and treatment.


Assuntos
Catequina , Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Ratos , Humanos , Animais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/genética , Catequina/metabolismo , Lipopolissacarídeos/farmacologia , Glicemia/metabolismo , Insulina , Fígado/metabolismo
17.
Foods ; 13(17)2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39272504

RESUMO

Lamb meat has become very popular with consumers in recent years due to its nutritional benefits. As a lean red meat, lamb is an important natural source of polyunsaturated and saturated fatty acids, which can be modified by adjustments in livestock feed. This study used proteomic and metabolic analyses to compare a basal ration supplemented with either mulberry silage or corn silage. Supplementation with mulberry silage led to a reduction in subcutaneous carcass fatness compared with corn silage. Additionally, changes in the proteome associated with fatty acid metabolism and oxidation resulted in decreased levels of saturated and trans fatty acids, while significantly increasing the levels of α-linolenic acid (ALA) and oleic acid and reducing linoleic acid content.

18.
Int J Biol Macromol ; 277(Pt 2): 134331, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39089538

RESUMO

Dietary management and interventions are crucial in the clinical management of diabetes. Numerous active dietary components in black tea have demonstrated positive effects on blood glucose levels and metabolic functions. However, limited research has explored the potential of theaflavins (TF), polyphenols in black tea, for diabetes management. In this study, high-purity TF was administered to Goto-Kakizaki (GK) diabetic model rats for four weeks to investigate its impact on diabetic pathology and analyze the underlying mechanisms through liver transcriptomics, hepatocyte metabolomics, and gut microbiome analysis. The findings indicated that continuous administration of TF (100 mg/kg) significantly suppressed blood glucose levels, reduced insulin resistance, and decreased the expression of oxidative stress indicators and inflammatory factors in GK rats. Further analysis revealed that TF might alleviate insulin resistance by improving hepatic glycogen conversion and reducing hepatic lipid deposition through modulation of key pathways, such as peroxisome proliferator-activated receptors and PI3K/AKT/GSK-3 pathways within the liver, thereby ameliorating diabetic symptoms. Additionally, TF intake facilitated the restoration of the intestinal microbial community structure by reducing the abundance of harmful bacteria and increasing the abundance of beneficial bacteria. It also reduced endotoxin lipopolysaccharide production, thereby lowering the chances of insulin resistance development and enhancing its efficacy in regulating blood glucose levels. These findings offer a novel perspective on the potential of black tea and its active constituents to prevent and treat diabetes and other metabolic disorders, providing valuable references for identifying and applying active dietary components from tea.


Assuntos
Biflavonoides , Catequina , Diabetes Mellitus Experimental , Microbioma Gastrointestinal , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Animais , Biflavonoides/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Catequina/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Masculino , Transdução de Sinais/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Resistência à Insulina , Glicemia/metabolismo , Glicemia/efeitos dos fármacos , Receptor de Insulina/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Chá/química , Estresse Oxidativo/efeitos dos fármacos
19.
Front Nutr ; 11: 1399390, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39149545

RESUMO

Introduction: In Northeast China, Dorper and Australian White rams are commonly crossbred with small-tailed Han (STH) ewes to improve the offspring's meat yield and quality. However, the differences in traits and the flavor between the crossbred sheep and STH sheep remain unclear. In addition, the candidate genes potentially influencing the meat quality in the three sheep breeds require further verification. Methods: A total of 18 2-month-old healthy rams were raised over a period of 5 months, which included 6 STH, 6 Dorper and small-tailed Han crossbred (Do × STH), and 6 Australian white and small-tailed Han crossbred (Au × STH) offspring. The differences in slaughter, meat quality traits, fatty acid and amino acid composition in the muscular longissimus dorsi (MLD), and volatile compounds in the semitendinosus muscle were compared between the sheep breeds. The candidate genes related to intramuscular fat (IMF) content and fatty acids were validated. Results: The results of this study revealed that the crossbred sheep had higher body weight, carcass weight, bone weight, net meat weight, and IMF content than the STH sheep (p < 0.05). The Do × STH offspring had a higher pH value (24 h), moisture content, and cooking percentage; they also had redder and brighter meat color. The content of myristate, palmitic, and margaric acids in the crossbred sheep was higher than that in the STH sheep (p < 0.05). The Do × STH offspring had the highest saturated fatty acid content (p < 0.05). The Au × STH offspring had the highest protein content (p < 0.05). The arachidonic acid and amino acid (Asp, Ala, Ile, Leu, Lys, Thr, and essential amino acid) contents were higher in the STH sheep than in the crossbred sheep (p < 0.05). The odor activity value (OAV) analysis showed that most of the aldehydes in the Au × STH offspring had higher values. The PDK4 gene expression was positively associated with the IMF content and was negatively correlated with the linoleic acid content in the Do × STH sheep (p < 0.05). The TMEM273 gene expression was positively associated with linoleic and arachidonic acid contents and was negatively correlated with oleic and palmitic acid contents in the Do × STH sheep (p < 0.05). Discussion: The results showed the differences between the crossbred sheep and STH sheep and provided the candidate genes related to meat quality in sheep.

20.
Artigo em Inglês | MEDLINE | ID: mdl-39142817

RESUMO

Sheep were domesticated in the Fertile Crescent and then spread globally, where they have been encountering various environmental conditions. The Tibetan sheep has adapted to high altitudes on the Qinghai-Tibet Plateau over the past 3000 years. To explore genomic variants associated with high-altitude adaptation in Tibetan sheep, we analyzed Illumina short-reads of 994 whole genomes representing ∼ 60 sheep breeds/populations at varied altitudes, PacBio High fidelity (HiFi) reads of 13 breeds, and 96 transcriptomes from 12 sheep organs. Association testing between the inhabited altitudes and 34,298,967 variants was conducted to investigate the genetic architecture of altitude adaptation. Highly accurate HiFi reads were used to complement the current ovine reference assembly at the most significantly associated ß-globin locus and to validate the presence of two haplotypes A and B among 13 sheep breeds. The haplotype A carried two homologous gene clusters: (1) HBE1, HBE2, HBB-like, and HBBC, and (2) HBE1-like, HBE2-like, HBB-like, and HBB; while the haplotype B lacked the first cluster. The high-altitude sheep showed highly frequent or nearly fixed haplotype A, while the low-altitude sheep dominated by haplotype B. We further demonstrated that sheep with haplotype A had an increased hemoglobin-O2 affinity compared with those carrying haplotype B. Another highly associated genomic region contained the EGLN1 gene which showed varied expression between high-altitude and low-altitude sheep. Our results provide evidence that the rapid adaptive evolution of advantageous alleles play an important role in facilitating the environmental adaptation of Tibetan sheep.


Assuntos
Altitude , Haplótipos , Animais , Ovinos/genética , Haplótipos/genética , Adaptação Fisiológica/genética , Transcriptoma/genética , Polimorfismo de Nucleotídeo Único/genética , Proteômica/métodos , Globinas beta/genética , Aclimatação/genética , Tibet , Multiômica
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