Genomic and Proteomic Analyses of the Fungus Arthrobotrys oligospora Provide Insights into Nematode-Trap Formation

Nematode-trapping fungi are “carnivorous” and attack their hosts using specialized trapping devices. The morphological development of these traps is the key indicator of their switch from saprophytic to predacious lifestyles. Here, the genome of the nematode-trapping fungus Arthrobotrys oligospora Fres. (ATCC24927) was reported. The genome contains 40.07 Mb assembled sequence with 11,479 predicted genes. Comparative analysis showed that A. oligospora shared many more genes with pathogenic fungi than with non-pathogenic fungi. Specifically, compared to several sequenced ascomycete fungi, the A. oligospora genome has a larger number of pathogenicity-related genes in the subtilisin, cellulase, cellobiohydrolase, and pectinesterase gene families. Searching against the pathogen-host interaction gene database identified 398 homologous genes involved in pathogenicity in other fungi. The analysis of repetitive sequences provided evidence for repeat-induced point mutations in A. oligospora. Proteomic and quantitative PCR (qPCR) analyses revealed that 90 genes were significantly up-regulated at the early stage of trap-formation by nematode extracts and most of these genes were involved in translation, amino acid metabolism, carbohydrate metabolism, cell wall and membrane biogenesis. Based on the combined genomic, proteomic and qPCR data, a model for the formation of nematode trapping device in this fungus was proposed. In this model, multiple fungal signal transduction pathways are activated by its nematode prey to further regulate downstream genes associated with diverse cellular processes such as energy metabolism, biosynthesis of the cell wall and adhesive proteins, cell division, glycerol accumulation and peroxisome biogenesis. This study will facilitate the identification of pathogenicity-related genes and provide a broad foundation for understanding the molecular and evolutionary mechanisms underlying fungi-nematodes interactions

Research on the Evolution of the Express Packaging Recycling Strategy, Considering Government Subsidies and Synergy Benefits

With the year-on-year growth of e-commerce transactions and the increasing popularity of the concept of ecological civilization, the waste and recycling of express packages have aroused widespread discussion and attention. On the issue of express package recycling, how consumers, e-commerce enterprises, and e-commerce platforms choose their own strategies, how to better promote the recycling of express packages, and what is the effect mechanism of government subsidies on different players. These are the questions that this article wants to answer. Since this article involves many stakeholders, in order to better identify the strategic choice and evolution of different entities and to better study the influence of government subsidies on the strategic choice of game players, this article uses two triparty evolutionary game models. The results show that without subsidies, changes in the rate of return and the initial probability will affect the evolution of the equilibrium strategy, while the synergistic benefits will have a corrective effect in some cases; when government subsidies are included and the probability of the three parties choosing “green strategies” is relatively low, subsidies should be paid to e-commerce companies mainly; lower subsidies can only provide incentives for e-commerce platforms. This article can provide certain references and value for government policymakers

The Relationship between Environmental Regulations and Green Economic Efficiency: A Study Based on the Provinces in China

This study examined the relationship between environmental regulations (ER) and green economic efficiency (GEE) based on the panel data of 30 provinces in China from 2008 to 2017. Firstly, GEE was calculated and evaluated using the super-efficiency SBM model with undesirable outputs. Secondly, the impact of ER on GEE was studied with the Tobit model. Finally, this article draws conclusions based on the above analysis and offers some suggestions for government and enterprise. The results show that the GEE of China is generally low. The GEE of the eastern region is much higher than that of the middle and western regions, with the western region performing slightly better than the middle. From west to east, there is a V shape, with high efficiency in the west and east and low efficiency in the middle. The impact of ER on GEE has the characteristics of nonlinearity and spatial heterogeneity. At the national level, as well as in the middle and western regions, the impact of ER on GEE shows an inverted U shape that first rises and then falls. ER are currently within the range conducive to the development of GEE. If the intensity of ER exceeds the critical value, they will have a negative impact on GEE. In the eastern region, the impact of ER on GEE is shown as a U shape that first falls and then rises. At present, the ER are not of sufficient intensity to contribute to the improvement of GEE. Only when the intensity of the ER exceeds the critical value will they have a positive influence on the GEE

Electron–Phonon Coupling-Mediated Ultralong Carrier Lifetime in an All-Inorganic Two-Dimensional Cs₂PbI₂Cl₂ Perovskite: Explanation for the High Antisite Defect Tolerance

Two-dimensional (2D) halide perovskite are appealing candidates for applications in optoelectronics and photovoltaics, but their energy conversion efficiency is severely limited by nonradiative electron–hole recombination. In most investigations, point defects with deep defect levels and deep charge-state transition levels in the band gap are treated as the carrier recombination centers. For the all-inorganic 2D Css 2PbI2Cl2, the IPb antisite defect is the most likely to form and cause nonradiative electron–hole recombination. By using density functional theory and ab initio nonradiative molecular dynamics calculations, we found that the IPb defect can introduce the deep acceptor and donor levels into the band gap. Because electron–phonon coupling gives rise to weak nonadiabatic coupling and rapid loss of electronic coherence, those levels lead to a reduction of the carrier loss and the prolongation of the excited-state carrier lifetime, thereby enhancing the photoelectric and defect tolerance properties of the Cs2PbI2Cl2 material. These results could deepen the understanding of the chemistry of defects and carrier dynamics in perovskite materials

Spectral selective fluorescence molecular imaging with volume holographic imaging system

A compact volume holographic imaging (VHI) method that can detect fluorescence objects located in diffusive medium in spectral selective imaging manner is presented. The enlargement of lateral field of view of the VHI system is realized by using broadband illumination and demagnification optics. Each target spectrum of fluorescence emitting from a diffusive medium is probed by tuning the inclination angle of the transmission volume holographic grating (VHG). With the use of the single transmission VHG, fluorescence images with different spectrum are obtained sequentially and precise three-dimensional (3D) information of deep fluorescent objects located in a diffusive medium can be reconstructed from these images. The results of phantom experiments demonstrate that two fluorescent objects with a sub-millimeter distance can be resolved by spectral selective imaging

MicroRNA-130b targets Fmr1 and regulates embryonic neural progenitor cell proliferation and differentiation

AbstractFragile X syndrome, one of the most common forms of inherited mental retardation, is caused by expansion of the CGG repeat in the 5′-untranslated region of the X-linked Fmr1 gene, which results in transcriptional silencing and loss of expression of its encoded protein FMRP. The loss of FMRP increases proliferation and alters fate specification in adult neural progenitor cells (aNPCs). However, little is known about Fmr1 mRNA regulation at the transcriptional and post-transcriptional levels. In the present study, we report that miR-130b regulated Fmr1 expression by directly targeting its 3′-untranslated region (3′ UTR). Up-regulation of miR-130b in mouse embryonic neural progenitor cells (eNPCs) decreased Fmr1 expression, markedly increased eNPC proliferation and altered the differentiation tendency of eNPCs, suggesting that antagonizing miR-130b may be a new therapeutic entry point for treating Fragile X syndrome

Spectral selective fluorescence molecular imaging with volume holographic imaging system

A compact volume holographic imaging (VHI) method that can detect fluorescence objects located in diffusive medium in spectral selective imaging manner is presented. The enlargement of lateral field of view of the VHI system is realized by using broadband illumination and demagnification optics. Each target spectrum of fluorescence emitting from a diffusive medium is probed by tuning the inclination angle of the transmission volume holographic grating (VHG). With the use of the single transmission VHG, fluorescence images with different spectrum are obtained sequentially and precise three-dimensional (3D) information of deep fluorescent objects located in a diffusive medium can be reconstructed from these images. The results of phantom experiments demonstrate that two fluorescent objects with a sub-millimeter distance can be resolved by spectral selective imaging

Depicting the Profile of METTL3-Mediated lncRNA m6A Modification Variants and Identified SNHG7 as a Prognostic Indicator of MNNG-Induced Gastric Cancer

As a representative example of an environmental chemical carcinogen, MNNG exposure is closely associated with the onset of gastric cancer (GC) where N6-methyladenosine (m6A) RNA methylation tends to be the critical epigenetic event. However, the effect of m6A modification on long non-coding RNAs (lncRNAs) in MNNG-induced GC onset is still unclear. To address the above issue, based on the Methylated RNA immunoprecipitation sequencing (MeRIP-seq) data of MNNG-induced malignant cells (MCs) and GC cells, we comprehensively analyzed the MNNG exposure-associated vital lncRNAs. MeRIP-seq analysis identified 1432 lncRNA transcripts in the MC cell, and 3520 lncRNA transcripts were found to be m6A modified in the GC cell, respectively. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that MNNG exposure could spark cellular localization change, which might be the critical cellular note variation for malignant transformation. We demonstrated that METTL3 is responsible for N6 methylation of lncRNAs and identified SNHG7 as a downstream target of METTL3. More importantly, we observed that SNHG7 was progressively up-regulated during gastric carcinogenesis by MNNG exposure. Finally, we investigated SNHG7 expression in different stages of GC malignancies and found that elevated SNHG7 expression correlated with advanced clinical features and poor prognosis in GC. In conclusion, our study found for the first time that METTL3 regulates the m6A methylation level of lncRNA SNHG7 and its expression in MNNG exposure-induced GC, suggesting that SNHG7 as a predictive biomarker or therapeutic target for GC

Splicing-Related Features of Introns Serve to Propel Evolution

<div><p>The role of spliceosomal intronic structures played in evolution has only begun to be elucidated. Comparative genomic analyses of fungal snoRNA sequences, which are often contained within introns and/or exons, revealed that about one-third of snoRNA-associated introns in three major snoRNA gene clusters manifested polymorphisms, likely resulting from intron loss and gain events during fungi evolution. Genomic deletions can clearly be observed as one mechanism underlying intron and exon loss, as well as generation of complex introns where several introns lie in juxtaposition without intercalating exons. Strikingly, by tracking conserved snoRNAs in introns, we found that some introns had moved from one position to another by excision from donor sites and insertion into target sties elsewhere in the genome without needing transposon structures. This study revealed the origin of many newly gained introns. Moreover, our analyses suggested that intron-containing sequences were more prone to sustainable structural changes than DNA sequences without introns due to intron's ability to jump within the genome via unknown mechanisms. We propose that splicing-related structural features of introns serve as an additional motor to propel evolution.</p> </div