Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 123
Filtrar
1.
Physiol Plant ; 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34549440

RESUMO

Water-saving and drought-resistant rice (WDR) is widely grown in central China in recent years. However, studies have not explored the interaction effect of WDR and irrigation regimes on drought-resistance capacities under severe drought at sensitive growth periods. A pot experiment was conducted using a WDR cultivar Hanyou73 (HY73) and traditional high-yielding and drought-sensitive cultivar Huiliangyou 898 (HLY898). Three irrigation regimes, including flooding irrigation (W1), mild wetting-drying alternation irrigation (W2), and severe wetting-drying alternation irrigation (W3), were applied before heading. At heading, severe drought with -50 KPa soil water potential was established for all treatments and cultivars. The findings showed that cultivar HY73 under W2 treatment had the highest yield, 1000-grain yield, filled grain, relative water content, and photosynthesis potential compared with the other combinations. The higher net photosynthetic rate (Pn ) was attributed to larger mesophyll conductance (gm ) in drought for cultivar HY73 under W2 treatment compared with that for cultivar HLY898 and the other water treatments. Enhanced photo-respiration rate may be an important photoprotection mechanism for achieving high Pn for cultivar HY73 coupled with W2 treatment than for other combinations in drought. The relative expression level of OsPIP1;1 gene was significantly down-regulated during drought in all cultivars and water regimes. But OsPIP1;2, OsPIP2;3, OsTIP2;2, and OsTIP3;1 genes were upregulated to alleviate the significant decrease in gs and gm under drought. These results suggest that WDR and mild wetting-drying alternation irrigation (W2) have significant interaction effects in improving photosynthetic production potential by maintaining higher gm under severe drought. This article is protected by copyright. All rights reserved.

2.
Parasit Vectors ; 14(1): 502, 2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34579769

RESUMO

BACKGROUND: Eimeria necatrix is one of the most pathogenic parasites, causing high mortality in chickens. Although its genome sequence has been published, the sequences and complete structures of its mRNA transcripts remain unclear, limiting exploration of novel biomarkers, drug targets and genetic functions in E. necatrix. METHODS: Second-generation merozoites (MZ-2) of E. necatrix were collected using Percoll density gradients, and high-quality RNA was extracted from them. Single-molecule real-time (SMRT) sequencing and Illumina sequencing were combined to generate the transcripts of MZ-2. Combined with the SMRT sequencing data of sporozoites (SZ) collected in our previous study, the transcriptome and transcript structures of E. necatrix were studied. RESULTS: SMRT sequencing yielded 21,923 consensus isoforms in MZ-2. A total of 17,151 novel isoforms of known genes and 3918 isoforms of novel genes were successfully identified. We also identified 2752 (SZ) and 3255 (MZ-2) alternative splicing (AS) events, 1705 (SZ) and 1874 (MZ-2) genes with alternative polyadenylation (APA) sites, 4019 (SZ) and 2588 (MZ-2) fusion transcripts, 159 (SZ) and 84 (MZ-2) putative transcription factors (TFs) and 3581 (SZ) and 2039 (MZ-2) long non-coding RNAs (lncRNAs). To validate fusion transcripts, reverse transcription-PCR was performed on 16 candidates, with an accuracy reaching up to 87.5%. Sanger sequencing of the PCR products further confirmed the authenticity of chimeric transcripts. Comparative analysis of transcript structures revealed a total of 3710 consensus isoforms, 815 AS events, 1139 genes with APA sites, 20 putative TFs and 352 lncRNAs in both SZ and MZ-2. CONCLUSIONS: We obtained many long-read isoforms in E. necatrix SZ and MZ-2, from which a series of lncRNAs, AS events, APA events and fusion transcripts were identified. Information on TFs will improve understanding of transcriptional regulation, and fusion event data will greatly improve draft versions of gene models in E. necatrix. This information offers insights into the mechanisms governing the development of E. necatrix and will aid in the development of novel strategies for coccidiosis control.

3.
Int Immunopharmacol ; 100: 108117, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34509933

RESUMO

FPS-ZM1 is an inhibitor of the receptor for advanced glycation end products (RAGE). Nevertheless, there are few reports about its direct effects on microglial inflammation, and the underlying molecular mechanisms remain to be clarified. The present study investigated the potential effects of FPS-ZM1 on lipopolysaccharide (LPS)-mediated microglial inflammation both in vivo and in vitro, and further elucidated the possible molecular mechanisms of action. FPS-ZM1 decreased LPS-induced overproduction of interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and cyclooxygenase 2 (COX-2), in both BV-2 cells and primary microglial cells. FPS-ZM1 (10 mg/kg, i.p.) ameliorated proliferation and activation of microglia in the hippocampus of C57BL/6J mice subjected to LPS challenge (5 mg/kg, i.p.). Meanwhile, overproduction of pro-inflammatory cytokines IL-1ß and TNF-α in the hippocampus was alleviated after treatment with FPS-ZM1. RNA-Sequencing (RNA-Seq) analysis showed involvement of Janus kinase (JAK)-signal transducers and activators of transcription (STAT) signaling pathway in the regulation of FPS-ZM1 on LPS-induced microglial inflammation. Further investigations demonstrated that FPS-ZM1 downregulated LPS-mediated increases in the phosphorylation levels of JAK/STAT both in vivo and in vitro. FPS-ZM1 also suppressed the nuclear translocation of transcription factor STAT1/3/5 in BV-2 cells. In addition, inhibition of JAK/STAT signaling pathway had an anti-inflammatory effect similar to FPS-ZM1 treatment. Taken together, our results verified the inhibitory effects of FPS-ZM1 against LPS-stimulated microglial inflammation, and for the first time demonstrated such anti-inflammatory activities on microglia are associated with regulation of JAK/STAT signaling pathway both in vivo and in vitro, which may shed new light on the pharmacological mechanisms of FPS-ZM1 against microglial inflammation.

4.
Inorg Chem ; 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34310118

RESUMO

Transition-metal phosphides and sulfides are considered as promising cocatalysts for the photocatalytic hydrogen evolution reaction (HER), and the cocatalytic effect can be improved by directed heterostructure engineering. In this study, a novel lattice-matched CoP/CoS2 heterostructure having a nanosheet morphology was developed as an HER cocatalyst and integrated in situ onto graphitic carbon nitride (g-C3N4) nanosheets via a successive phosphorization and vulcanization route. First-principles density functional theory calculations evidenced that the construction of the lattice-matched CoP/CoS2 heterostructure resulted in the redistribution of interface electrons, enhanced metallic characteristics, and improved H* adsorption. As a result of these effects, the CoP/CoS2 heterostructure cocatalyst formed a 2D/2D Schottky junction with the g-C3N4 nanosheets, thus promoting photoelectron transfer to CoP/CoS2 and realizing fast charge-carrier separation and good HER activity. As expected, the CoP/CoS2 heterostructure exhibited excellent cocatalytic activity, and the optimal loading of the cocatalyst on g-C3N4 enhanced its HER activity to 3.78 mmol g-1 h-1. This work furnishes a new perspective for the development of highly active noble-metal-free cocatalysts via heterostructure engineering for water splitting applications.

5.
Analyst ; 146(15): 4803-4810, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34241602

RESUMO

Pattern recognition, also called "array sensing," is a recognition strategy with a wide and expandable analysis range, based on high-throughput analysis data. In this work, we constructed a sensor array for the identification of targets including bacterial pathogens and proteins by using FAM-labeled DNA probes and 2D nanosheet materials. We designed an ordered and extendible DNA library for the collection of recognition probes. Unlike traditional DNA probes with random and massive sequences, our DNA library was constructed following a 5-digit binary number (00000-11111, 0 = CCC, and 1 = TTT), and especially, 8 special symmetry sequences were chosen from the library. Two different nanosheet materials were used as the quencher. When targets were added, the interaction between DNA and the nanosheets was competitively affected, and as a result, the fluorescence signal changed accordingly. Finally, by using our fluorescent sensor array, 17 bacteria and 8 proteins were precisely recognized. We believe that our work has provided a simple and valuable strategy for the improvement of the recognition range and discrimination precision for the development of pattern recognition.


Assuntos
Nanoestruturas , DNA/genética , Sondas de DNA/genética , Corantes Fluorescentes , Biblioteca Gênica , Espectrometria de Fluorescência
6.
J Hazard Mater ; 421: 126690, 2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34315019

RESUMO

Shellfish toxins are derived from harmful algae and are easily accumulated in environment and marine food through the food chain, exposing high risks on human health. Preliminary rapid screening is one of the most effective monitoring ways to reduce the potential risks; however, the traditional methods encounter with many limitations, such as complicated procedures, low sensitivity and specificity, and ethical problems. Alternatively, bioaffinity sensors are proposed and draw particular attention. Among them, the aptasensors are springing up and emerging as superior alternatives in recent years, exhibiting high practicability to analyze shellfish toxins in real samples in the marine food chain. Herein, the latest research progresses of aptasensors towards shellfish toxins in the marine food chain in the past five years was reviewed for the first time, in terms of the aptamers applied in these aptasensors, construction principles, signal transduction techniques, response types, individual performance properties, practical applications, and advantages/disadvantages of these aptasensors. Synchronously, critical discussions were given and future perspectives were prospected. We hope this review can serve as a powerful reference to promote further development and application of aptasensors to monitor shellfish toxins, as well as other analytes with similar demands.

7.
Anal Chim Acta ; 1173: 338710, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34172145

RESUMO

Saxitoxin (STX) is a small molecule toxin (Mw. ca. 299 g/mol) with high acute toxicity, and it has urgent need of facile analytical methods. Herein, a competitive colorimetric aptasensor was developed for highly sensitive detection of STX. An anti-STX aptamer was hybridized with a complementary strand on the magnetic beads and was competitively bound by STX. The supernatant containing the aptamer binding to STX was obtained by magnetic separation, which could trigger hybridization chain reaction (HCR) to generate rigid double stranded DNAs (dsDNAs) with sticky end and variable length. These HCR-dsDNAs were found to be able to facilitate significant enhancement on the peroxidase-like catalytic capability of AuNPs nanozyme towards 3,3,5,5-tetramethylbenzidine (TMB). The concentration of STX was responded in a "turn on" mode, based on the amplified colorimetric transduction thereof. The aptasensor realized high sensitivity, with a limit of detection (LOD) as low as 42.46 pM. Moreover, a wide linear detection range of 78.13-2500 pM, good selectivity, as well as good recovery rates of 106.2-113.5% when analyzing STX in real shellfish samples were obtained. This strategy could be referred to develop robust aptasensors for simple and highly sensitive detection of other small molecules and toxins.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas Metálicas , Catálise , Colorimetria , Ouro , Limite de Detecção , Saxitoxina
8.
Vet Parasitol ; 296: 109480, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34120030

RESUMO

Eimeria necatrix is one of the most pathogenic chicken coccidia and causes avian coccidiosis, an enteric disease of major economic importance worldwide. Eimeria parasites have complex developmental life cycles, with an exogenous phase in the environment and an endogenous phase in the chicken intestine. Oocysts excreted by chickens rapidly undergo meiosis and cell division to form eight haploid sporozoites (SZ). SZ liberated from sporocysts in the chicken intestine migrate to their preferred site of development to initiate cellular invasion. To date, almost nothing is known about the proteins that mediate parasite invasion in E. necatrix. In order to discover genes with functions involved in cellular invasion, the transcriptome profiles of E. necatrix unsporulated oocysts (UO) and SZ were analyzed using a combination of third-generation single-molecule real-time sequencing (TGS) and second-generation sequencing (SGS) followed by qRT-PCR validation. Correction of TGS long reads by SGS short reads resulted in 34,932 (UO) and 23,040 (SZ) consensus isoforms. After subsequent assembly, a total of 4949 and 4254 genes were identified from UO and SZ libraries, respectively. A total of 8376 genes were identified as differentially expressed genes (DEGs) between SZ and UO. Compared to UO, 4057 genes were upregulated and 4319 genes were downregulated in SZ. Approximately 1399 and 1758 genes were defined as stage-specific genes in SZ and UO, respectively. Gene Ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that 2978 upregulated SZ genes were clustered into 29 GO terms, and 857 upregulated SZ genes were associated with 26 KEGG pathways. We also predicted a further 50 upregulated SZ genes and 73 upregulated UO genes encoding microneme proteins, apical membrane antigens, rhoptry neck proteins, rhoptry proteins, dense granule proteins, heat shock proteins, calcium-dependent protein kinases, cyclin-dependent kinases, cGMP-dependent protein kinase, and glycosylphosphatidylinositol-anchored surface antigens. Our data reveal new features of the E. necatrix transcriptional landscape and provide resources for the development of novel vaccine candidates against E. necatrix infection.


Assuntos
Eimeria , Interações Hospedeiro-Parasita , Oocistos , Esporozoítos , Transcriptoma , Animais , Galinhas , Eimeria/genética , Interações Hospedeiro-Parasita/genética , Oocistos/genética , Análise de Sequência de RNA/veterinária , Esporozoítos/genética , Transcriptoma/genética
9.
Food Chem ; 364: 130361, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34153597

RESUMO

The residual tetracyclines in food are frequently applied as the model compounds to develop aptasensors. Until now, more than 100 advanced aptasensors towards tetracyclines have been developed and published in English. This review summarizes and discusses comprehensively these advanced aptasensors, in terms of the principle designs, applied frontier transducers/materials, working performance, and advantages/disadvantages. The aptasensors are classified according to the inherent transduction techniques, i.e., optics, optics-electricity, optics-mass, and electricity-mass. Moreover, the present challenges such as the limited specificity and limited affinity of the aptamers, the future prospects and trends such as further combination with other advanced materials and technologies, and the urgent need of expanding the practical application were discussed and prospected. We hope this review can serve as a powerful tool for both tracing the development progresses of aptasensors and providing adequate references for further development of aptasensing methods for food-related analytes.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Antibacterianos , Análise de Alimentos , Tetraciclinas
11.
Taiwan J Obstet Gynecol ; 60(3): 449-453, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33966726

RESUMO

OBJECTIVE: The purpose of this study is to analyze uterine electromyography burst patterns in patients with spontaneous labor and patients with uterine inertia. MATERIALS AND METHODS: Uterine electromyography was recorded using 4 silver/silver chloride electrodes placed periumbilical. Thirty women in the spontaneous labor were enrolled. Uterine electromyography was also recorded from patients with uterine inertia before and after oxytocin treatment. EMG bursts were characterized by analysis of multiple variables including burst frequency, duration, root mean squared, amplitude, and total power. RESULTS: There were significant reductions (P < .01) in all EMG burst characteristics. In addition, uterine electromyography parameters were all increased after oxytocin treatment and were comparable (P > .05) to patients in spontaneous labor. CONCLUSIONS: Uterine electromyography can be used effectively to distinguish patients progressing with spontaneous labor from patients that develop uterine inertia. Uterine inertia is characterized by reduced EMG activity and failure of cervical dilation. Uterine electromyography is a quantitative, non-invasive assessment tool that contributes to the diagnosis, evaluation and management of patients with spontaneous labor and uterine inertia.

12.
Org Biomol Chem ; 19(18): 3960-3982, 2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-33978039

RESUMO

Bridged polycycles are privileged molecular skeletons with wide occurrence in bioactive natural products and pharmaceuticals. Therefore, they have been the pursing target molecules of numerous chemists. The rapid and convenient generation of sp3-rich complex three-dimensional molecular skeletons from simple and easily available aromatics has made dearomatization a highly valuable synthetic tool for the construction of rigid and challenging bridged rings. This review summarizes the-state-of-the-art advances of dearomatization strategies in the application of bridged ring formation, discusses their advantages and limitations and the in-depth mechanism, and highlights their synthetic value in the total synthesis of natural products. We wish this review will provide an important reference for medicinal and synthetic chemists and will inspire further development in this intriguing research area.

13.
Analyst ; 146(11): 3526-3533, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-33881427

RESUMO

Since the application of RNA interference (RNAi) is rapidly developing in GMO technology, accurate and sensitive detection of functional RNA molecules was urgently needed, for the safety and functional assessment of RNAi crops. In this work, we developed an electrochemical biosensor for transgene-derived long RNA based on a poly-adenine (polyA) DNA capture probe. The polyA self-assembling monolayer (SAM) provided enhanced interface stability and optimized surface density for the subsequent hybridization of the long RNA molecule. A multiple reporter probe system (MRP) containing 12 reporter probes (RPs) and 2 spacers was applied to open the complex molecular secondary structure and hybridize with the long RNA, with the critical assistance of dimethyl sulfoxide (DMSO). By using 3 addressable RPs, structural recognition was performed among long stem-loop RNA, long dsRNA (no loop), and siRNA. Excellent selectivity was achieved when the extracted total RNA samples were directly analyzed. When reverse transcription recombinase polymerase amplification (RT-RPA) technology was combined, the sensitivity was improved to 10 aM. To the best of our knowledge, this is the first electrochemical biosensor with the excellent capability of quantification and structural analysis of the long RNA of the RNAi GMO. Our work shows great potential in a wide range of RNAi GMO samples.


Assuntos
Técnicas Biossensoriais , Zea mays , Sondas de DNA , Técnicas Eletroquímicas , Poli A , Interferência de RNA , Zea mays/genética
14.
Opt Lett ; 46(9): 2192-2195, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33929452

RESUMO

We demonstrate, to the best of our knowledge, the first high-power large-mode-area Er:Yb codoped fiber amplifier pumped by 1018 nm fiber lasers. The output power reaches 219.6 W, which is the highest power operating at 1600 nm with near-diffraction-limitation beam quality. The 1018 nm pumping scheme contributes to the mitigation of Er,Yb fiber bottlenecking, improvement in signal gain, and reduction of heat generation. Also, we inject co-propagating C-band amplified spontaneous emission (ASE) into the master amplifier to avoid unwanted backward-propagating ASE.

15.
Mol Cell Biochem ; 476(7): 2791-2801, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33719002

RESUMO

Term labour is associated with activation of inflammation which results in myometrial contractility, cervical ripening and decidual/membrane rupture. Serum amyloid A1 (SAA1) is an acute response protein, whose role and underlying regulatory mechanisms in human labour remain unknown. In this study, we found that the mRNA and protein expression of SAA1 in human myometrium at term was increased in labouring tissues compared to non-labouring tissues. In addition, the expression of SAA1 was significantly increased in human primary myometrial cells treated with the pro-inflammatory cytokines interleukin-1 beta (IL-1ß) or tumour necrosis factor-alpha (TNF-α). Knockdown of SAA1 using siRNA (siSAA1) resulted in a significant reduction in the expression and secretion of pro-inflammatory cytokines (IL8, IL6), chemokines (CXCL5, CCL2), adhesion molecules (ICAM1, ICAM5) and contraction-associated factors (COX2, PGE2). Mechanistically, the effects of SAA1 were mediated through activation of the Yes-associated protein (YAP) pathway. There was a decrease in the protein expression of phosphorylated YAP (pYAP) after treatment of siSAA1-transfected human primary myometrial cells with IL-1ß or TNF-α. Moreover, enhanced expression of YAP reversed the effect of siSAA1 on pro-labour mediators. In conclusion, these experiments demonstrated that SAA1 accelerates the inflammatory response associated with parturition by activating YAP pathway, which may be a novel understanding of the molecular mechanism of labour onset.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Citocinas/metabolismo , Miométrio/metabolismo , Parto/metabolismo , Proteína Amiloide A Sérica/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Adulto , Feminino , Humanos
16.
Gynecol Obstet Invest ; 86(1-2): 88-93, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33596572

RESUMO

INTRODUCTION: Parturition involves multiple complex metabolic processes that supply essential metabolites to facilitate fetal delivery. Little is known about the dynamic metabolic responses during labor. OBJECTIVE: To profile the changes of myometrial metabolites between nonlabor and labor. METHODS: The study involved 30 women in nonlabor and 30 in labor who underwent cesarean section. The characteristics of myometrial metabolite changes during parturition were explored through untargeted metabolomic analysis. Data were analyzed by multivariate and univariate statistical analysis. RESULTS: Partial least squares-discriminant analysis plots significantly differentiated between the groups. In total, 392 metabolites were significantly distinct between the groups, among which lipid molecules were predominant. A 75% increase in fatty acids, 67% increase in fatty acid carnitines, 66% increase in glycerophospholipids, 83% increase in mono- and diacylglycerols, and 67% decrease in triacyclglycerols were observed in the patients during labor. Most glucose, amino acid, and steroid hormone metabolism also slightly increased in labor. CONCLUSIONS: An increase in lipolysis, fatty acid oxidation, amino acid catabolism, and steroid hormone metabolism was observed during parturition. The change of lipolysis and fatty acid oxidation is the most significant.


Assuntos
Trabalho de Parto/metabolismo , Metaboloma , Miométrio/metabolismo , Parto/metabolismo , Adulto , Cesárea , Feminino , Humanos , Gravidez
17.
BMC Dev Biol ; 21(1): 4, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33517884

RESUMO

BACKGROUND: Our previous study have shown that the PSMD11 protein was an important survival factor for cancer cells except for its key role in regulation of assembly and activity of the 26S proteasome. To further investigate the role of PSMD11 in carcinogenesis, we constructed a conditional exon 5 floxed allele of PSMD11 (PSMD11flx) in mice. RESULTS: It was found that homozygous PSMD11 flx/flx mice showed normal and exhibited a normal life span and fertility, and showed roughly equivalent expression of PSMD11 in various tissues, suggesting that the floxed allele maintained the wild-type function. Cre recombinase could induce efficient knockout of the floxed PSMD11 allele both in vitro and in vivo. Mice with constitutive single allele deletion of PSMD11 derived from intercrossing between PSMD11flx/flx and CMV-Cre mice were all viable and fertile, and showed apparent growth retardation, suggesting that PSMD11 played a significant role in the development of mice pre- or postnatally. No whole-body PSMD11 deficient embryos (PSMD11-/-) were identified in E7.5-8.5 embryos in uteros, indicating that double allele knockout of PSMD11 leads to early embryonic lethality. To avoid embryonic lethality produced by whole-body PSMD11 deletion, we further developed conditional PSMD11 global knockout mice with genotype Flp;FSF-R26CAG - CreERT2/+; PSMD11 flx/flx, and demonstrated that PSMD11 could be depleted in a temporal and tissue-specific manner. Meanwhile, it was found that depletion of PSMD11 could induce massive apoptosis in MEFs. CONCLUSIONS: In summary, our data demonstrated that we have successfully generated a conditional knockout allele of PSMD11 in mice, and found that PSMD11 played a key role in early and postnatal development in mice, the PSMD11 flx/flx mice will be an invaluable tool to explore the functions of PSMD11 in development and diseases.

18.
Plant Physiol ; 186(2): 865-873, 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-33638984

RESUMO

Reproductive isolation is a prerequisite to form and maintain a new species. Multiple prezygotic and postzygotic reproductive isolation barriers have been reported in plants. In the model plant, Arabidopsis thaliana conspecific pollen tube precedence controlled by AtLURE1/PRK6-mediated signaling has been recently reported as a major prezygotic reproductive isolation barrier. By accelerating emergence of own pollen tubes from the transmitting tract, A. thaliana ovules promote self-fertilization and thus prevent fertilization by a different species. Taking advantage of a septuple atlure1null mutant, we now report on the role of AtLURE1/PRK6-mediated signaling for micropylar pollen tube guidance. Compared with wild-type (WT) ovules, atlure1null ovules displayed remarkably reduced micropylar pollen tube attraction efficiencies in modified semi-in vivo A. thaliana ovule targeting assays. However, when prk6 mutant pollen tubes were applied, atlure1null ovules showed micropylar attraction efficiencies comparable to that of WT ovules. These findings indicate that AtLURE1/PRK6-mediated signaling regulates micropylar pollen tube attraction in addition to promoting emergence of own pollen tubes from the transmitting tract. Moreover, semi-in vivo ovule targeting competition assays with the same amount of pollen grains from both A. thaliana and Arabidopsis lyrata showed that A. thaliana WT and xiuqiu mutant ovules are mainly targeted by own pollen tubes and that atlure1null mutant ovules are also entered to a large extent by A. lyrata pollen tubes. Taken together, we report that AtLURE1/PRK6-mediated signaling promotes conspecific micropylar pollen tube attraction representing an additional prezygotic isolation barrier.

19.
J Matern Fetal Neonatal Med ; 34(8): 1297-1303, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31269830

RESUMO

BACKGROUND: Excessive trophoblasts erosivity is the main pathological manifestation in placenta accreta. Similar to early pregnancy, trophoblasts of placenta accreta might have a similar anoxic state in abnormal continuous invasion, in which autophagy may also have some changes causing invasive ability in accreta. METHODS: Ten accreta placentas (placenta accreta group), as well as 10 non-accreta placentas (control group), were collected according to accreta criteria. The expression of hypoxia-induced autophage factors (HIF1α, Beclin 1, LC3B, and P62) and invasion-related markers (E-cadherin and MMP-9) were detected using immunohistochemical method. Comparison in scores grade was made between the two groups by Fisher's exact test and Spearman's test was used for correlation analysis. RESULTS: HIF1α was mainly expressed in cytomembrane of trophoblasts, in which moderate positive 50% (5/10) and strong positive 50% (5/10) in placenta accreta group compared to 50% (5/10) or weak positive 30% (3/10) in control group, with a significant statistically difference (p < .05). The negative, weak positive, moderate positive, and strong positive rates of Beclin-1 expression were 0, 10, 30, and 60% versus 60, 40, 0, and 0% in placenta accreta group and control group, respectively, statistically different (p < .05). The expression of LC3B was also statistically significant (0, 10, 20, 70% versus 50, 20, 30, 0%) between two groups, and P62 expression was also statistically different between two groups. The positive rates of E-cadherin expression were obviously negatively correlated with Beclin-1, LC3B, and P62 expression, while positive rates of MMP-9 expression were positively correlated with autophagy-associated markers. CONCLUSIONS: Hypoxia state might be involved in the occurrence of placental accreta, and persistent hypoxia state induced autophage disorders could cause down-regulated E-cadherin and down-regulated MMP-9, thus leading to more invasiveness of placenta trophoblasts.


Assuntos
Placenta Acreta , Trofoblastos , Autofagia , Feminino , Humanos , Hipóxia , Placenta , Gravidez
20.
Plant Reprod ; 34(1): 47-60, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33258014

RESUMO

KEY MESSAGE: Analyses of secretomes of in vitro grown pollen tubes from Amborella, maize and tobacco identified many components of processes associated with the cell wall, signaling and metabolism as well as novel small secreted peptides. Flowering plants (angiosperms) generate pollen grains that germinate on the stigma and produce tubes to transport their sperm cells cargo deep into the maternal reproductive tissues toward the ovules for a double fertilization process. During their journey, pollen tubes secrete many proteins (secreted proteome or secretome) required, for example, for communication with the maternal reproductive tissues, to build a solid own cell wall that withstands their high turgor pressure while softening simultaneously maternal cell wall tissue. The composition and species specificity or family specificity of the pollen tube secretome is poorly understood. Here, we provide a suitable method to obtain the pollen tube secretome from in vitro grown pollen tubes of the basal angiosperm Amborella trichopoda (Amborella) and the Poaceae model maize. The previously published secretome of tobacco pollen tubes was used as an example of eudicotyledonous plants in this comparative study. The secretome of the three species is each strongly different compared to the respective protein composition of pollen grains and tubes. In Amborella and maize, about 40% proteins are secreted by the conventional "classic" pathway and 30% by unconventional pathways. The latter pathway is expanded in tobacco. Proteins enriched in the secretome are especially involved in functions associated with the cell wall, cell surface, energy and lipid metabolism, proteolysis and redox processes. Expansins, pectin methylesterase inhibitors and RALFs are enriched in maize, while tobacco secretes many proteins involved, for example, in proteolysis and signaling. While the majority of proteins detected in the secretome occur also in pollen grains and pollen tubes, and correlate in the number of mapped peptides with relative gene expression levels, some novel secreted small proteins were identified. Moreover, the identification of secreted proteins containing pro-peptides indicates that these are processed in the apoplast. In conclusion, we provide a proteome resource from three distinct angiosperm clades that can be utilized among others to study the localization, abundance and processing of known secreted proteins and help to identify novel pollen tube secreted proteins for functional studies.


Assuntos
Magnoliopsida , Tubo Polínico , Óvulo Vegetal , Peptídeos , Tabaco , Zea mays
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...