Development of a High-throughput Sequencing Platform for Detection of Viral Encephalitis Pathogens Based on Amplicon Sequencing

Objective Viral encephalitis is an infectious disease severely affecting human health.It is caused by a wide variety of viral pathogens,including herpes viruses,flaviviruses,enteroviruses,and other viruses.The laboratory diagnosis of viral encephalitis is a worldwide challenge.Recently,high-throughput sequencing technology has provided new tools for diagnosing central nervous system infections.Thus,In this study,we established a multipathogen detection platform for viral encephalitis based on amplicon sequencing.Methods We designed nine pairs of specific polymerase chain reaction(PCR)primers for the 12 viruses by reviewing the relevant literature.The detection ability of the primers was verified by software simulation and the detection of known positive samples.Amplicon sequencing was used to validate the samples,and consistency was compared with Sanger sequencing.Results The results showed that the target sequences of various pathogens were obtained at a coverage depth level greater than 20×,and the sequence lengths were consistent with the sizes of the predicted amplicons.The sequences were verified using the National Center for Biotechnology Information BLAST,and all results were consistent with the results of Sanger sequencing.Conclusion Amplicon-based high-throughput sequencing technology is feasible as a supplementary method for the pathogenic detection of viral encephalitis.It is also a useful tool for the high-volume screening of clinical samples.

Variation of microbiological and small molecule metabolite profiles of Nuodeng ham during ripening by high-throughput sequencing and GC-TOF-MS

The internal microbial diversity and small molecular metabolites of Nuodeng ham in different processing years(the first,second and third year sample)were analyzed by high-throughput sequencing technology and gas chromatography-time of flight mass spectrography(GC-TOF-MS)to study the effects of microorganisms and small molecular metabolites on the quality of ham in different processing years.The results showed that the dominant bacteria phyla of Nuodeng ham in different processing years were Proteobacteria and Firmicutes,the dominant fungi phyla were Ascomycota and Basidiomycota,while Staphylococcus and Aspergillus were the dominant bacteria and fungi of Nuodeng ham,respectively.Totally,252 kinds of small molecular metabolites were identified from Nuodeng ham in different processing years,and 12 different metabolites were screened through multivariate statistical analysis.Further metabolic pathway analysis showed that 23 metabolic pathways were related to ham fermentation,of which 8 metabolic pathways had significant effects on ham fermentation(Impact>0.01,P<0.05).The content of L-proline,phenyllactic acid,L-lysine,carnosine,taurine,D-proline,betaine and creatine were significantly positively correlated with the relative abundance of Staphylococcus and Serratia,but negatively correlated with the relative abundance of Halomonas,Aspergillus and Yamadazyma.

Development and Characterization of Microsatellite Markers for Harpadon nehereus Based on High-Throughput Sequencing and Cross-Species Amplification in Three Myctophiformes Fishes

Harpadon nehereus is a widespread economical fish found in the coastal seas of China and has important ecological value in the marine ecosystem.H_(o)wever,its germplasm resources have been seriously degraded due to natural factors and anthropogenic activities.In this study,high-throughput sequencing was applied to search for microsatellite loci in H.nehereus transcriptome to provide references for its resource conservation and utilization.Polymorphic loci were developed by non-denaturing polyacrylamide gel electrophoresis,and their cross-species amplified ability was detected in three related species.A total of 5652 microsatellites were identified from 16974320 unigenes.Among the primer pairs designed for 100 SSRs for PCR amplification,80%were successfully amplified,and 26 loci were polymorphic with a high number of alleles from 3 to 11 each.The expected(H_(e))and observed(H_(o))heterozygosities were 0.355–0.885 and 0.375–0.958,respectively.Most of the loci were highly polymorphic(polymorphism information content:0.316–0.852;mean:0.713),and these markers can be applied in the population genetic diversity research of H.nehereus.H_(o)wever,the transferability of these primers was low,probably because of the close relation of the collected species.In follow-up work,simple sequence repeats will be excavated with genome-based technologies,and related species will be gathered to address the present inadequacies.

Identification of novel salt stress-responsive microRNAs through sequencing and bioinformatic analysis in a unique halophilic Dunaliella salina strain

Dunaliella salina is a classic halophilic alga.However,its molecular mechanisms in response to high salinity at the post transcriptional level remain unknown.A unique halophilic alga strain,DS-CN1,was screened from four D.salina strains via cell biological,physiological,and biochemical methods.High-throughput sequencing of small RNAs(sRNAs)of DS-CN1 in culture medium containing 3.42-mol/L NaCl(SS group)or 0.05-mol/L NaCl(CO group)was performed on the BGISEQ-500 platform.The annotation and sequences of D.salina sRNAs were profiled.Altogether,44 novel salt stress-responsive microRNAs(miRNAs)with a relatively high C content,with the majority of them being 24 nt in length,were identified and characterized in DS-CN1.Twenty-one differentially expressed miRNAs(DEMs)in SS and CO were screened via bioinformatic analysis.A total of 319 putative salt stress-related genes targeted(104 overlapping genes)by novel miRNAs in this alga were screened based on our previous transcriptome sequencing research.Furthermore,these target genes were classified and enriched by GO and KEGG pathway analysis.Moreover,5 novel DEMs(dsa-mir3,dsa-mir16,dsa-mir17,and dsa-mir26 were significantly upregulated,and dsa-mir40 was significantly downregulated)and their corresponding 10 target genes involved in the 6 significantly enriched metabolic pathways were verified by quantitative real-time PCR.Next,their regulatory relationships were comprehensively analyzed.Lastly,a unique salt stress response metabolic network was constructed based on the novel DEM-target gene pairs.Taken together,our results suggest that 44 novel salt stress-responsive microRNAs were identified,and 4 of them might play important roles in D.salina upon salinity stress and contribute to clarify its distinctive halophilic feature.Our study will shed light on the regulatory mechanisms of salt stress responses.

Differential Expression and Regulation of Switchgrass Root MicroRNA in Response to Alkali-salt Stress Using High-throughput Deep Sequencing

Switchgrass(Panicum virgatum L.)as a high-quality bioenergy crop that can effectively improve saline-alkali soil has strong resistance to stress and grows well in marginal soil and some abiotic stress environments.This study used alkali-sensitive genotype AM(AM-314/MS-155)and alkali-tolerant genotype ALA(Alamo)as experimental materials to investigate molecular mechanisms of switchgrass tolerance to alkali-salt stress.When the plants were grown to E5 stage,the alkali-salt stress treatment was carried out by soaking method(Na2CO3:NaHCO3=1:9,C(Na+)=150 mmol·L-1 and pH=9.0)and fresh root samples were taken after treatments for 0(CK),6 and 24 h,respectively,the differentially expressed microRNAs and their regulatory network were analyzed.A total of 1049 known miRNAs and 68 novel miRNAs were identified.Seventy-two differentially expressed miRNAs in ALA were more than three times higher than those in AM and 36.1%differentially expressed miRNAs was significantly down-regulated(p<0.05).Through analyses of differentially expressed miRNAs and their target genes,it was found that under alkali-salt stress,differentially expressed miRNAs in AM were mainly involved in the regulation of cellular ROS clearance,ethylene signal transduction,and root,leaf and flower development.MiRNAs in ALA were also involved in water transport,DNA methylation,response to high osmotic pressure,activation of stress-related genes and more complex responses to alkali-salt stress processes,but those in AM were not.ALA was significantly higher than AM in the number of microRNAs responding to alkali-salt stress and in the functional diversity of their regulatory target genes.

A MicroRNA Catalog of Swine Umbilical Vein Endothelial Cells Identified by Deep Sequencing

MicroRNAs （miRNAs） are endogenous -22 nt RNAs that play important regulatory roles in targeting mRNAs for cleavage or translational repression. Despite the discovery of increasing numbers of human and mouse miRNAs, little is known about miRNAs from pig. In this study, we sought to extend the repertoire of porcine small regulatory RNAs using Solexa sequencing. We sequenced a library of small RNAs prepared from immortalized swine umbilical vein endothelial cells （SUVECs）. We produced over 13.6 million short sequence reads, of which 8 547 658 perfectly mapped to the pig genome. A bioinformatics pipeline was used to identify authentic mature miRNA sequences. We identified 154 porcine miRNA genes, among which 146 were conserved across species, and 8 were pig-specific miRNA genes. The 146 miRNA genes encoded 116 conserved mature miRNAs and 66 miRNA^＊. The 8 pig-specific miRNA genes encoded 4 mature miRNAs. Four potential novel miRNAs were identified. The secondary structures of the 154 miRNA genes were predicted; 13 miRNAs have 2 structures, and miR-9 and miR-199 have 4 and 3 structures, respectively. 36 miRNAs were organized into 19 compact clusters, miR-206, miR-21 and miR-378 were the relatively highly expressed miRNAs. In conclusion, Solexa sequencing allowed the successful discovery of known and novel porcine miRNAs with high accuracy and efficiency. Furthermore, our results supply new data to the somewhat insufficient pig miRBase, and are useful for investigating features of the blood-brain barrier, vascular diseases and inflammation.

High-throughput Sequencing Technology and Its Application

Gene sequencing is a great way to interpret life, and high-throughput sequencing technology is a revolutionary technological innovation in gene sequencing researches. This technology is characterized by low cost and high-throughput data. Currently, high-throughput sequencing technology has been widely applied in multi-level researches on genomics, transcriptomics and epigenomics. And it has fundamentally changed the way we approach problems in basic and translational researches and created many new possibilities. This paper presented a general description of high-throughput sequencing technology and a comprehensive review of its application with plain, concisely and precisely. In order to help researchers finish their work faster and better, promote science amateurs and understand it easier and better.

Comparison of rumen archaeal diversity in adult and elderly yaks(Bos grunniens)using 16S rRNA gene high-throughput sequencing

This study was conducted to investigate the phylogenetic diversity of archaea in the rumen of adult and elderly yaks. Six domesticated female yaks, 3 adult yaks （（5.3±0.6） years old）, and 3 elderly yaks （（10.7±0.6） years old）, were used for the rumen contents collection. Illumina MiSeq high-throughput sequencing technology was applied to examine the archaeal composition of rumen contents. A total of 92 901 high-quality archaeal sequences were analyzed, and these were assigned to 2 033 operational taxonomic units （OTUs）. Among these, 974 OTUs were unique to adult yaks while 846 OTUs were unique to elderly yaks; 213 OTUs were shared by both groups. At the phylum level, more than 99% of the obtained OTUs belonged to the Euryarchaeota phylum. At the genus level, the archaea could be divided into 7 archaeal genera. The 7 genera （i.e., Methanobrevibacter, Methanobacterium, Methanosphaera, Thermogymnomonas, Methanomicrobiu, Meth- animicrococcus and the unclassified genus） were shared by all yaks, and their total abundance accounted for 99% of the rumen archaea. The most abundant archaea in elderly and adult yaks were Methanobrevibacterand Thermogymnomonas, respectively. The abundance of Methanobacteria （class）, Methanobacteriales （order）, Methanobacteriaceae （family）, and Methanobrevibacter （genus） in elderly yaks was significantly higher than in adult yaks. In contrast, the abundance of Ther-mogymnomonas in elderly yaks was 34% lower than in adult yaks, though the difference was not statistically significant. The difference in abundance of other archaea was not significant between the two groups. These results suggested that the structure of archaea in the rumen of yaks changed with age. This is the first study to compare the phytogenetic differences of rumen archaeal structure and composition using the yak model.

Genome-wide identification of RNA editing in seven porcine tissues by matched DNA and RNA high-throughput sequencing

Background: RNA editing is a co/posttranscriptional modification mechanism that increases the diversity of transcripts, with potential functional consequences. The advent of next-generation sequencing technologies has enabled the identification of RNA edits at unprecedented throughput and resolution. However, our knowledge of RNA editing in swine is still limited.Results: Here, we utilized RES-Scanner to identify RNA editing sites in the brain, subcutaneous fat, heart, liver,muscle, lung and ovary in three 180-day-old Large White gilts based on matched strand-specific RNA sequencing and whole-genome resequencing datasets. In total, we identified 74863 editing sites, and 92.1% of these sites caused adenosine-to-guanosine(A-to-G) conversion. Most A-to-G sites were located in noncoding regions and generally had low editing levels. In total, 151 A-to-G sites were detected in coding regions(CDS), including 94 sites that could lead to nonsynonymous amino acid changes. We provide further evidence supporting a previous observation that pig transcriptomes are highly editable at PRE-1 elements. The number of A-to-G editing sites ranged from 4155(muscle) to 25001(brain) across the seven tissues. The expression levels of the ADAR enzymes could explain some but not all of this variation across tissues. The functional analysis of the genes with tissuespecific editing sites in each tissue revealed that RNA editing might play important roles in tissue function.Specifically, more pathways showed significant enrichment in the fat and liver than in other tissues, while no pathway was enriched in the muscle.Conclusions: This study identified a total of 74863 nonredundant RNA editing sites in seven tissues and revealed the potential importance of RNA editing in tissue function. Our findings largely extend the porcine editome and enhance our understanding of RNA editing in swine.

Microbial diversity in Huguangyan Maar Lake of China revealed by high-throughput sequencing

Huguangyan Maar Lake is a typical maar lake in the southeast of China. It is well preserved and not disturbed by anthropogenic activities. In this study, microbial community structures in sediment and water samples from Huguangyan Maar Lake were investigated using a high-throughput sequencing method. We found significant differences between the microbial community compositions of the water and the sediment. The sediment samples contained more diverse Bacteria and Archaea than did the water samples. Actinobacteria, Betaproteobacteria, Cyanobacteria, and Deltaproteobacteria predominated in the water samples while Deltaproteobacteria, Anaerolineae, Nitrospira, and Dehalococcoidia were the major bacterial groups in the sediment. As for Archaea, Woesearchaeota (DHVEG-6), unclassified Archaea, and Deep Sea Euryarchaeotic Group were detected at higher abundances in the water, whereas the Miscellaneous Crenarchaeotic Group, Thermoplasmata, and Methanomicrobia were significantly more abundant in the sediment. Interactions between Bacteria and Archaea were common in both the water column and the sediment. The concentrations of major nutrients (NO^3-, PO4^3-, SiO3^2- and NH4^+) shaped the microbial population structures in the water. At the higher phylogenetic levels including phylum and class, many of the dominant groups were those that were also abundant in other lakes;however, novel microbial populations (unclassified) were often seen at the lower phylogenetic levels. Our study lays a foundation for examining microbial biogeochemical cycling in sequestered lakes or reservoirs.

High-throughput sequencing analysis of the regulation of intestinal flora in giant pandas with indigestion using a probiotic agent LyPB

This study aimed to investigate the eff ect of LyPB on the intestinal microfl ora of giant pandas with indigestion,using high-throughput sequencing(HTS)technology.The species distribution and microfl oral density and diversity before and after administration of the LyPB probiotic agent were analyzed.LyPB evidently has the ability to adjust the fl oral imbalance in the panda’s intestine.To test the eff ects of LyPB on the microfl ora of the panda gut,fecal samples were taken from a healthy giant panda(Anan)without administration of LyPB and from a dyspeptic giant panda Yangyang before and after LyPB administration.Compared with the sample obtained from healthy Anan(anan-c)and that obtained from dyspeptic Yangyang before LyPB administration(yangyang1),the sample taken from Yangyang(yangyang2)after LyPB administration displayed a signifi cant increase in the operational taxonomic unit index.An increase in the Chao index indicated an increase in the microfl oral richness,while an increase in the Shannon index indicated an increase in microfl oral diversity.At phylum and genus levels,a signifi cant increase was observed in the density of probiotic bacteria of phylum fi rmicutes,genus Streptococcus,while a drastic reduction in the density of Escherichia coli/Escherichia coli Shigella/bacteria of genus Shigella was observed.Data obtained in this study shows that LyPB preparations successfully improve the microbial structure within the panda’s intestinal canal by signifi cantly increasing the eff ective microbial community and decreasing the number of pathogenic microbes.

Identification of Zinc Deficiency-Responsive MicroRNAs in Brassica juncea Roots by Small RNA Sequencing

The importance of zinc （Zn） as a micronutrient essential for plant growth and development is becoming increasingly apparent. Much of the world’s soil is Zn-deficient, and soil-based Zn deficiency is often accompanied by Zn deficiency in human populations. MicroRNAs （miRNAs） play important roles in the regulation of plant gene expression at the level of translation. Many miRNAs involved in the modulation of heavy metal toxicity responses in plants have been identiifed;however, the role of miRNAs in the plant Zn deifciency response is almost completely unknown. Using high-throughput Solexa sequencing, we identiifed several miRNAs that respond to Zn deifciency in Brassica juncea roots. At least 21 conserved candidate miRNA families, and 101 individual members within those families, were identiifed in both the control and the Zn-deifcient B. juncea roots. Among this, 15 miRNAs from 9 miRNA families were differentially expressed in the control and Zn-deifcient plants. Of the 15 differentially expressed miRNAs, 13 were up-regulated in the Zn-deifcient B. juncea roots, and only two, miR399b and miR845a, were down-regulated. Bioinformatics analysis indicated that these miRNAs were involved in modulating phytohormone response, plant growth and development, and abiotic stress responses in B. juncea roots. These data help to lay the foundation for further understanding of miRNA function in the regulation of the plant Zn deifciency response and its impact on plant growth and development.

Differential mRNA expression profiling of oral squamous cell carcinoma by high-throughput RNA sequencing

Differentially expressed genes are thought to regulate the development and progression of oral squamous cell carcinomas （OSCC）. The purpose of this study was to screen differentially expressed mRNAs in OSCC and matched paraneoplastic normal tissues, and to explore the intrinsic mechanism of OSCC development and progres- sion. We obtained the differentially expressed mRNA expression profiles in 10 pairs of fresh-frozen OSCC tissue specimens and matched paraneoplastic normal tissue specimens by high-throughput RNA sequencing. By using Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway enrichment analyses, the functional significance of the differentially expressed genes were analyzed. We identified 1,120 sig- nificantly up-regulated mRNAs and 178 significantly down-regulated mRNAs in OSCC, compared to normal tissue. The differentially expressed mRNAs were involved in 20 biological processes and 68 signal pathways. Compared to adjacent normal tissue, the expression of MAGEAll was up-regulated; TCHH was down-regulated. These find- ings were verified by real-time PCR. These differentially expressed mRNAs may function as oncogenes or tumor suppressors in the development and progression of OSCC. This study provides novel insights into OSCC. However, further work is needed to determine if these differentially expressed mRNAs have potential roles as diagnostic bio- markers and candidate therapeutic targets for OSCC.

MicroRNA and mRNA profiling of cerebral cortex in a transgenic mouse model of Alzheimer’s disease by RNA sequencing

In a previous study,we found that long non-coding genes in Alzheimer’s disease(AD)are a result of endogenous gene disorders caused by the recruitment of microRNA(miRNA)and mRNA,and that miR-200a-3p and other representative miRNAs can mediate cognitive impairment and thus serve as new biomarkers for AD.In this study,we investigated the abnormal expression of miRNA and mRNA and the pathogenesis of AD at the epigenetic level.To this aim,we performed RNA sequencing and an integrative analysis of the cerebral cortex of the widely used amyloid precursor protein and presenilin-1 double transgenic mouse model of AD.Overall,129 mRNAs and 68 miRNAs were aberrantly expressed.Among these,eight down-regulated miRNAs and seven up-regulated miRNAs appeared as promising noninvasive biomarkers and therapeutic targets.The main enriched signaling pathways involved mitogen-activated kinase protein,phosphatidylinositol 3-kinase-protein kinase B,mechanistic target of rapamycin kinase,forkhead box O,and autophagy.An miRNA-mRNA network between dysregulated miRNAs and corresponding target genes connected with AD progression was also constructed.These miRNAs and mRNAs are potential biomarkers and therapeutic targets for new treatment strategies,early diagnosis,and prevention of AD.The present results provide a novel perspective on the role of miRNAs and mRNAs in AD.This study was approved by the Experimental Animal Care and Use Committee of Institute of Medicinal Biotechnology of Beijing,China(approval No.IMB-201909-D6)on September 6,2019.

Characterization of Bacterial Community Associated with Four Organs of the Yesso Scallop (Patinopecten yessoensis) by High-Throughput Sequencing

We used Illumina high-throughput sequencing of PCR-amplified V3-V4 16 S rRNA gene regions to characterize bacterial communities associated with the adductor muscles, gills, gonads and intestines of the Yesso scallop(Patinopecten yessoensis) from waters around Zhangzidao, Dalian, China. Overall, 421,276 optimized reads were classified as 25 described bacterial phyla and 308 genera. Firmicutes, Proteobacteria, Tenericutes, Bacteroidetes, Chlamydiae and Spirochaetae accounted for > 97% of the total reads in the four organs. The bacterial 16 S rDNA sequences assigned to Firmicutes and Proteobacteria were abundant in the adductor muscles, gills and gonads; while reads from Tenericutes were dominant in the intestines, followed by those from Firmicutes, Chlamydiae, Proteobacteria and Bacteroidetes. At the genus level, the dominant genera in the adductor muscles, gills and gonads appeared to be Bacillus, Enterococcus and Lactococcus, whereas Mycoplasma was dominant in the intestines. The relative abundances of Bacillus, Enterococcus, Lactococcus, Alkaliphilus, Raoultella, Paenibacillus and Oceanobacillus were significantly lower in the intestine than in the other three organs. Cluster analysis and principal coordinates analysis of the operational taxonomy units profile revealed significant differences in the bacterial community structure between the intestine and the other three organs. Taken together, these results suggest that scallops have intestine-specific bacterial communities and the adductor muscles, gills and gonads harbor similar communities. The difference in the bacterial community between organs may relate to unique habitats, surroundings, diet and their respective physiological functions.

基于小RNA转录组测序的扩展青霉胞内microRNA研究

微小RNA(miRNA)在真核基因表达调控中具有广泛的作用.为了探索miRNA在分子水平上对采后病原菌扩展青霉发育及致病力形成的影响,对扩展青霉菌丝进行了小RNA转录组测序分析.共检测到1个已知miRNA和17个新预测的miRNA,揭示了它们的序列、前体结构和潜在的靶基因信息,并与指状青霉胞内miRNA进行了比较分析.

Profile and development of microsatellite primers for Acanthogobius ommaturus based on high-throughput sequencing technology

Acanthogobius ommaturus,a fish species of the Family Gobiidae,is a marine commercial fish perched on the bottom of seawater.In this study,Illumina high-throughput sequencing technology was applied to obtain the candidate microsatellite markers of A.ommaturus.A total of 4746 microsatellite-rich fragments were found,of which 4542 microsatellites are with primer fragments,containing 971 dinucleotide sequences,2643 trinucleotide sequences,569 tetranucleotide sequences,406 pentanucleotide sequences,and 212 hexanucleotide sequences.Based on the results of high-throughput sequencing,a total of 141 pairs of the microsatellite primers were designed and screened.And then 24 polymorphic primers were finally obtained by polyacrylamide gel electrophoresis.In total,271 alleles were detected in the 24 pairs of primers.The number of alleles for different primers ranged from 5 to 19.The average number of effective alleles(Na)was 11.292;the average observed heterozygosity(Ho)of the 24 pairs of primers was 0.665,the average expected heterozygosity(He)was 0.880,and the average polymorphic information content was 0.846.All sites were highly polymorphic(PIC>0.50).

High-throughput sequencing analysis of differentially expressed mi RNAs and target genes in ischemia/reperfusion injury and apelin-13 neuroprotection

miRNAs regulate a variety of biological processes through pairing-based regulation of gene expression at the 3＇ end of the noncoding region of the target miRNA, miRNAs were found to be abnormally expressed in ischemia/reperfusion injury models. High-throughput sequencing is a recently developed method for sequencing miRNAs and has been widely used in the analysis of miRNAs. In this study, ischemia/reperfusion injury models were intracerebroventricularly injected with 50 pg/kg apelin-13. High-throughput sequencing showed that 357 known miRNAs were differentially expressed among rat models, among which 78 changed to 〉 2-fold or 〈 0.5-fold. Quantita- tive real-time polymerase chain reaction was selected to confirm the expression levels of four miRNAs that were differentially expressed, the results of which were consistent with the results of high-throughput sequencing. Gene Ontology analysis revealed that the predicted targets of the different miRNAs are particularly associated with cellular process, metabolic process, single-organism process, cell, and binding. Kyoto Encyclopedia of Gene and Genome analysis showed that the target genes are involved in metabolic pathways, mitogen-ac- tivated protein kinase signaling pathway, calcium signaling pathway, and nuclear factor-KB signaling pathway. Our findings suggest that differentially expressed miRNAs and their target genes play an important role in ischemia/reperfusion injury and neuroprotection by apelin-13.

Gelatin filter capture-based high-throughput sequencing analysis of microbial diversity in haze particulate matter

Airborne particulate matter(PM),especially PM2.5,can be easily adsorbed by human respiratory system.Their roles in carrying pathogens for spreading epidemic diseases has attracted great concern.Herein,we developed a novel gelatin filter-based and culture-independent method for investigation of the microbial diversity in PM samples during a haze episode in Tianjin,China.This method involves particle capture by gelatin filters,filter dissolution for DNA extraction,and high-throughput sequencing for analysis of the microbial diversity.A total of 584 operational taxonomic units(OTUs)of bacteria and 370 OTUs of fungi at the genus level were identified during hazy days.The results showed that both bacterial and fungal diversities could be evaluated by this method.This study provides a convenient strategy for investigation of microbial biodiversity in haze,facilitating accurate evaluation of airborne epidemic diseases.

Identification and profiling of microRNAs of Euphausia superba using Illumina deep sequencing

MicroRNAs(miRNAs) are an abundant class of conserved, non-coding small RNAs that play important role in gene regulation at post translational level. There have been no reports on the miRNAs of the Antarctic krill E uphausia superba despite the species' crucial position in Antarctic food webs. Two small RNA libraries were constructed from eyestalk and muscle, subsequently, and deep sequencing analysis was performed to investigate and profile E. superba miRNAs. A total of 19 304 586 and 23 005 104 unique sequences were obtained from the eyestalk and muscle, respectively. After compared the small RNA sequences with the Rfam database, 12 342 039 and 7 907 477 reads in eyestalk and muscle were matched to the transcriptome sequence of E. superba. A total of 236 distinct miRNAs were identified after annotation to known animal miRNAs registered in miRBase 21. In both libraries, the most abundant known miRNA were miR-750 with 92 583 reads in muscle and miR-1304-3 p with 56 386 reads in eyestalk while the average value was less than 106, revealing a wide range of different expression levels. In addition, miR-277 a enriched in both libraries and may be involved in modulating Krebs cycle by targeting to Vimar. Differential expression analysis showed that 56 mature miRNAs were significantly up/down regulated according to expression fold change. It appeared that the expression of several abundant miRNAs maybe tissue-specific or tissue-bias. Notably, the expression pattern of miR-750 and miR-1 family, which was suggested as the crucial candidates, involved in muscle development. Taken together, this study provides the first miRNA profile of E. superba and some of these miRNAs were expected to play important role in immune response, reproduction, energy metabolism, and muscle development and so on. Thus, the results provides a reference for functional studies of miRNAs in E. superba.