How insect communities are assembled in nature remains largely unknown. In particular, whether habitat filtering or competition serves as the main mechanism in forming insect communities is rarely ...subject to an in-depth investigation. One bottleneck lies in the difficulty of species identification when dealing with a large number of diverse insects. However, high-throughput sequencing technology coupled with classic DNA barcoding offers a great opportunity to infer community assembly for this speciose group. In this study, using 13,909 full-length barcodes obtained by Sanger sequencing or the full-length metabarcoding method (SOAPBarcode), we showed that competition was the main assembly mechanism for the moth communities in the younger Taihang Mountain, while habitat filtering for those in the old Yanshan Mountain. The two sequencing methods showed highly consistent results with regards to both diversity composition and community assembly mechanism. Significant phylogenetic signals and structure suggested that the focal moth communities were the result of the non-neutral assembly process, which was further confirmed by results of neutral assembly test that accounted for immigration and speciation rates. Our study showed that the full-length metabarcoding method can facilitate community assembly inferences, even for speciose taxonomic groups.
The advent in high-throughput-sequencing (HTS) technologies has revolutionized conventional biodiversity research by enabling parallel capture of DNA sequences possessing species-level diagnosis. ...However, polymerase chain reaction (PCR)-based implementation is biased by the efficiency of primer binding across lineages of organisms. A PCR-free HTS approach will alleviate this artefact and significantly improve upon the multi-locus method utilizing full mitogenomes. Here we developed a novel multiplex sequencing and assembly pipeline allowing for simultaneous acquisition of full mitogenomes from pooled animals without DNA enrichment or amplification. By concatenating assemblies from three de novo assemblers, we obtained high-quality mitogenomes for all 49 pooled taxa, with 36 species >15 kb and the remaining >10 kb, including 20 complete mitogenomes and nearly all protein coding genes (99.6%). The assembly quality was carefully validated with Sanger sequences, reference genomes and conservativeness of protein coding genes across taxa. The new method was effective even for closely related taxa, e.g. three Drosophila spp., demonstrating its broad utility for biodiversity research and mito-phylogenomics. Finally, the in silico simulation showed that by recruiting multiple mito-loci, taxon detection was improved at a fixed sequencing depth. Combined, these results demonstrate the plausibility of a multi-locus mito-metagenomics approach as the next phase of the current single-locus metabarcoding method.
Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved. We inferred the phylogeny of insects from 1478 protein-coding genes. ...Phylogenomic analyses of nucleotide and amino acid sequences, with site-specific nucleotide or domain-specific amino acid substitution models, produced statistically robust and congruent results resolving previously controversial phylogenetic relationships. We dated the origin of insects to the Early Ordovician ~479 million years ago (Ma), of insect flight to the Early Devonian (~406 Ma), of major extant lineages to the Mississippian (~345 Ma), and the major diversification of holometabolous insects to the Early Cretaceous. Our phylogenomic study provides a comprehensive reliable scaffold for future comparative analyses of evolutionary innovations among insects.
Understanding diversity patterns requires accounting for the roles of both historical and contemporary factors in the assembly of communities. Here, we compared diversity patterns of two moth ...assemblages sampled from Taihang and Yanshan mountains in Northern China and performed ancestral range reconstructions using the Multi‐State Speciation and Extinction model, to track the origins of these patterns. Further, we estimated diversification rates of the two moth assemblages and explored the effects of contemporary ecological factors. From 7,788 specimens we identified 835 species belonging to 23 families, using both DNA barcode analysis and morphology. Moths in Yanshan mountains showed higher species diversity than in Taihang mountains. Ancestral range analysis indicated Yanshan as the origin, with significant historical dispersals from Yanshan to Taihang. Asymmetrical diversification, population expansion, along with frequent and considerable gene flow were detected between communities. Moreover, dispersal limitation or the joint effect of environment filtering and dispersal limitation were inferred as main driving forces shaping current diversity patterns. In summary, we demonstrate that a multiscale (community, population and species level) analysis incorporating both historical and contemporary factors can be useful in delineating factors contributing to community assembly and patterning in diversity.
see also the Perspective by Susan R. Kennedy and Henrik Krehenwinkel.
Zinc is an essential minor element for rice growth and human health, which can also change the structure of the microorganisms. However, it remains unclear for the effects of zinc fertilizer on ...microbiome function in agricultural soils and crops. To solve this research gap, we investigated the relationship between improving rice (
Oryza sativa
L.) yield, Zn concentration, soil microbial community diversity, and function by the application of Zn fertilizer. The field trials included three rice varieties (Huanghuazhan, Nanjing9108, and Nuodao-9925) and two soil Zn levels (0 and 30 kg ha
–1
) in Jiangsu province, China. As a test, we studied the variety of soil bacterial composition, diversity, and function using 16S rRNA gene sequencing. The results showed that soil Zn application reduced the diversity of microbial community, but the bacterial network was more closely linked, and the metabolic function of bacterial community was improved, which increased the grain yield (17.34–19.52%) and enriched the Zn content of polished rice (1.40–20.05%). Specifically, redundancy analysis (RDA) and Mantel’s test results revealed soil total nitrogen (TN) was the primary driver that led to a community shift in the rice rhizosphere bacterial community, and soil organic carbon (SOC) was considered to have a strong influence on dominant phyla. Furthermore, network analysis indicated the most critical bacterial taxa were identified as
Actinobacteria, Bacteroidetes, Proteobacteria
, and
Chloroflexi
based on their topological roles of microorganisms. KEGG metabolic pathway prediction demonstrated that soil Zn application significantly (
p
< 0.05) improved lipid metabolism, amino acid metabolism, carbohydrate metabolism, and xenobiotic biodegradation. Overall, their positive effects were different among rice varieties, of which Nanjing-9108 (NJ9108) performed better. This study opens new avenues to deeply understand the plant and soil–microbe interactions by the application of fertilizer and further navigates the development of Zn-rich rice cultivation strategies.
To reduce the pain caused by subcutaneous injections, microneedle patches as the new transdermal drug delivery method are gaining increased attention. In this study, we fabricated a composite ...insulin-loaded microneedle patch. Silk fibroin, a natural polymer material, was used as the raw material. The tip of the microneedle had good dissolving property and was able to dissolve rapidly to promote the release of insulin. The pedestal had the property of swelling without dissolving and was carrying insulin as a drug store. The insulin carried by the pedestal could release continuously through the micropore channels created by the microneedles. This kind of microneedle could achieve a sustained release effect. It was observed that the insulin had good storage stability in this kind of microneedle, and it maintained more than 90% of its biological activity after 30 days. The results of transdermal delivery to diabetic rats showed that the microneedle patches displayed an apparent hypoglycemic effect and indicated a sustained release effect. These drug-loaded silk microneedle patches may act as potential delivery systems for the treatment of diabetes.
Silk fibroin is a widely used biocompatible medical material with tunable mechanical, degradability and environmental non-toxicity. This paper prepared the silk fibroin/chitosan hydrogel microneedle ...with pH sensitivity by blending silk fibroin with chitosan to induce graft cross-linking. The cross-linked silk fibroin/chitosan microneedles network is expanded by hydrogen ions and water molecules, forming a more significant swelling. In vitro, the transdermal drug release showed that insulin loaded in microneedles exhibited pH-sensitive drug release behavior and was released faster under acidic conditions than under neutral conditions. By changing the pH of the solution, microneedles can achieve a stimulating response to the environment, thereby intelligently regulating the transdermal release of insulin.
Atom transfer radical polymerization (ATRP) is a "living"/controlled radical polymerization, which is also used for surface grafting of various materials including textiles. However, the commonly ...used metal complex catalyst, CuBr, is mildly toxic and results in unwanted color for textiles. In order to replace the transition metal catalyst of surface-initiated ATRP, the possibility of HRP biocatalyst was investigated in this work. 2-hydroxypropyl methacrylate (HPMA) was grafted onto the surface of silk fabric using the horseradish peroxidase (HRP) biocatalyzed ATRP method, which is used to improve the crease resistance of silk fabric. The structure of grafted silk fabric was characterized by Fourier transform infrared spectrum, X-ray photoelectron spectroscopy, thermogravimetic analysis, and scanning electron microscopy. The results showed that HPMA was successfully grafted onto silk fabric. Compared with the control silk sample, the wrinkle recovery property of grafted silk fabric was greatly improved, especially the wet crease recovery property. However, the whiteness, breaking strength, and moisture regain of grafted silk fabric decreased somewhat. The present work provides a novel, biocatalyzed, environmentally friendly ATRP method to obtain functional silk fabric, which is favorable for clothing application and has potential for medical materials.
•The TL peaks began to shift to lower temperature with increasing TiO2.•The integral luminous areas of OSL curves increase with increasing TiO2.•TL intensity and TL curve width increase with ...increasing beta dose.
Ti,Mg:α-Al2O3 transparent ceramics were successfully fabricated by conventional sintering process under vacuum condition. The SEM micrographs showed that TiO2 effectively inhibited excessive grain growth of Ti,Mg:α-Al2O3 transparent ceramics as sintering proceeds. The fluorescence spectra, thermoluminescence and optically stimulated luminescence of Ti,Mg:α-Al2O3 transparent ceramics were compared to its single crystals. The influence of different content of TiO2 on the thermoluminescence and optically stimulated luminescence of Ti,Mg:α-Al2O3 transparent ceramics were studied. The results showed that the thermoluminescence peaks began to shift to lower temperature with increasing content of TiO2, and the intensity of thermoluminescence peaks increased. The integral luminous areas of OSL curves increased with the increasing content of TiO2.
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