cPAS-based sequencing on the BGISEQ-500 to explore small non-coding RNAs

Placental Transcriptome Analysis in Connection with Low Litter Birth Weight Phenotype (LBWP) Sows

It is possible to identify sub-populations of sows in every pig herd that consistently give birth to low birth weight (BW) piglets, irrespective of the litter size. A previous study from our group demonstrated that placental development is a main factor affecting the litter birth weight phenotype (LBWP) in sows, thereby impacting the BW of entire litters, but the biological and molecular pathways behind this phenomenon are largely unknown. The aim of this study was to investigate the differential gene expression in placental tissues at day 30 of gestation between low LBWP (LLBWP) vs. high LBWP (HLBWP) sows from a purebred Large White maternal line. Using mRNA sequencing, we found 45 differentially expressed genes (DEGs) in placental tissues of LLBWP and HLBWP sows. Furthermore, (GO) enrichment of upregulated DEGs predicted that there were two biological processes significantly related to cornification and regulation of cell population proliferation. To better understand the molecular interaction between cell proliferation and cornification, we conducted transcriptional factor binding site (TFBS) prediction analysis. The results indicated that a highly significant TFBS was located at the 5' upstream of all four upregulated genes (CDSN, DSG3, KLK14, KRT17), recognized by transcription factors EGR4 and FOSL1. Our findings provide novel insight into how transcriptional regulation of two different biological processes interact in placental tissues of LLBWP sows.

Testicular piRNA Analysis Identified Dysregulated piRNAs in Non-obstructive Azoospermia

Male infertility has remained idiopathic in a remarkable proportion of all cases. Gonadal expression of PIWI-interacting RNAs (piRNAs) has been shown to be vital to normal spermatogenesis, as they are expressed in almost all types of testicular germ cells. These molecules and their related Piwi proteins strictly regulate transposable elements' activity and gene expression. We aimed to identify dysregulated piRNAs in idiopathic non-obstructive azoospermic (NOA) testis by global expression analysis. Testis tissue samples from 18 azoospermic patients (ten NOA and eight OA) were studied by small RNA sequencing. To validate high-throughput sequencing data, quantitative real-time polymerase chain reactions for two differentially altered piRNAs were performed. Bioinformatics analyses were undertaken to identify pathways affected by piRNA dysregulation. In the NOA group, 1328 piRNAs were identified to be differentially expressed, of which 1322 were downregulated and 6 were upregulated. Bioinformatics analysis corroborated the involvement of dysregulated piRNA in spermatogenesis. We also identified 64 clusters of differentially expressed piRNAs, of which 42 clusters had a minimum of ten absolute piRNA hits. Our study suggests that piRNAs show significant dysregulation in infertility. Their target genes play a role in their self-biogenesis, probably by regulating their own production through a feedback mechanism. The downregulated piRNAs may find value as biomarkers for the presence of spermatozoa in the testis of azoospermic individuals, while the upregulated piRNAs are great candidates for further investigation of their precise functions in spermatogenesis.

Comparative transcriptomic analysis of Illumina and MGI next-generation sequencing platforms using RUNX3- and ZBTB46-instructed embryonic stem cells

Introduction: We have previously observed phenotypic and developmental changes upon the ectopic expression of the RUNX3 or the ZBTB46 transcription factors in mouse embryonic stem cell (ESC) derived progenitors. In this study, we evaluated the gene expression profiles of the RUNX3- and the ZBTB46-instructed murine ESCs with RNA-seq testing two next-generation sequencing technologies. Methods: We compared the DNA nanoball-based DNBSEQ G400 sequencer (MGI) with the bridge-PCR-based NextSeq 500 instrument (Illumina) for RNA sequencing. Moreover, we also compared two types of MGI sequencing reagents (Standard versus Hot-massive parallel sequencing (MPS)) with the DNBSEQ G400. Results: We observed that both sequencing platforms showed comparable levels of quality, sequencing uniformity, and gene expression profiles. For example, highly overlapping RUNX3- and ZBTB46-regulated gene lists were obtained from both sequencing datasets. Moreover, we observed that the Standard and the Hot-MPS-derived RUNX3- and ZBTB46-regulated gene lists were also considerably overlapped. This transcriptome analysis also helped us to identify differently expressed genes in the presence of the transgenic RUNX3 or ZBTB46. For example, we found that Gzmb, Gzmd, Gzme, Gdf6, and Ccr7 genes were robustly upregulated upon the forced expression of Runx3; on the other hand, Gpx2, Tdpoz4, and Arg2 were induced alongside the ectopic expression of Zbtb46. Discussion: Similar gene expression profile and greatly overlapping RUNX3- and ZBTB46-regulated gene sets were detected with both DNA sequencing platforms. Our analyses demonstrate that both sequencing technologies are suitable for transcriptome profiling and target gene selection. These findings suggest that DNBSEQ G400 represents a cost-effective alternative sequencing platform for gene expression monitoring. Moreover, this analysis provides a resource for exploration of the RUNX3- and ZBTB46-dependent gene regulatory networks.

Comprehensive clinical assays for molecular diagnostics of gliomas: the current state and future prospects

Glioma is one of the most intractable types of cancer, due to delayed diagnosis at advanced stages. The clinical symptoms of glioma are unclear and due to a variety of glioma subtypes, available low-invasive testing is not effective enough to be introduced into routine medical laboratory practice. Therefore, recent advances in the clinical diagnosis of glioma have focused on liquid biopsy approaches that utilize a wide range of techniques such as next-generation sequencing (NGS), droplet-digital polymerase chain reaction (ddPCR), and quantitative PCR (qPCR). Among all techniques, NGS is the most advantageous diagnostic method. Despite the rapid cheapening of NGS experiments, the cost of such diagnostics remains high. Moreover, high-throughput diagnostics are not appropriate for molecular profiling of gliomas since patients with gliomas exhibit only a few diagnostic markers. In this review, we highlighted all available assays for glioma diagnosing for main pathogenic glioma DNA sequence alterations. In the present study, we reviewed the possibility of integrating routine molecular methods into the diagnosis of gliomas. We state that the development of an affordable assay covering all glioma genetic aberrations could enable early detection and improve patient outcomes. Moreover, the development of such molecular diagnostic kits could potentially be a good alternative to expensive NGS-based approaches.

Complete chloroplast genome of Lens lamottei reveals intraspecies variation among with Lens culinaris

Lens lamottei is a member of the Fabaceae family and the second gene pool of the genus Lens. The environmental factors that drove the divergence among wild and cultivated species have been studied extensively. Recent research has focused on genomic signatures associated with various phenotypes with the acceleration of next-generation techniques in molecular profiling. Therefore, in this study, we provide the complete sequence of the chloroplast genome sequence in the wild Lens species L. lamottei with a deep coverage of 713 × next-generation sequencing (NGS) data for the first time. Compared to the cultivated species, Lens culinaris, we identified synonymous, and nonsynonymous changes in the protein-coding regions of the genes ndhB, ndhF, ndhH, petA, rpoA, rpoC2, rps3, and ycf2 in L. lamottei. Phylogenetic analysis of chloroplast genomes of various plants under Leguminosae revealed that L. lamottei and L. culinaris are closest to one another than to other species. The complete chloroplast genome of L. lamottei also allowed us to reanalyze previously published transcriptomic data, which showed high levels of gene expression for ATP-synthase, rubisco, and photosystem genes. Overall, this study provides a deeper insight into the diversity of Lens species and the agricultural importance of these plants through their chloroplast genomes.

Transcriptomic analysis of Amaranthus retroflex resistant to PPO-inhibitory herbicides

Amaranthus retroflexus L. is one of the malignant weeds which can cause a reduction in the soybean yield. We found a population of A. retroflexus (R-Q) resistant to fomesafen through the initial screening of whole-plant dose response bioassay in the research. The resistance index of the population (R-Q) was 183 times of the sensitive population (S-N). The resistant and sensitive populations were used as experimental materials in the paper. Strand-specific RNA-Seq analyses of R‒Q and S‒N populations obtained from herbicide-treated and mock-treated leaf samples after treatment were conducted to generate a full-length transcriptome database. We analyzed differentially expressed genes (DEGs) among the R-Q and S‒N A. retroflexus populations treated with recommended dose and mock-treated on the 1st (24 h) and 3rd (72 h) days to identify genes involved in fomesafen resistance. All 82,287 unigenes were annotated by Blastx search with E-value < 0.00001 from 7 databases. A total of 94,815 DEGs among the three group comparisons were identified. Two nuclear genes encoding PPO (PPX1 and PPX2) and five unigenes belonging to the AP2-EREBP, GRAS, NAC, bHLH and bZIP families exhibited different expression patterns between individuals of S‒N and R-Q populations. The A. retroflexus transcriptome and specific transcription factor families which can respond to fomesafen in resistant and susceptible genotypes were reported in this paper. The PPX1 and PPX2 genes of the target enzyme were identified. The study establishes the foundation for future research and provides opportunities to manage resistant weeds better.

Cross-platform comparisons for targeted bisulfite sequencing of MGISEQ-2000 and NovaSeq6000

BACKGROUND

An accurate and reproducible next-generation sequencing platform is essential to identify malignancy-related abnormal DNA methylation changes and translate them into clinical applications including cancer detection, prognosis, and surveillance. However, high-quality DNA methylation sequencing has been challenging because poor sequence diversity of the bisulfite-converted libraries severely impairs sequencing quality and yield. In this study, we tested MGISEQ-2000 Sequencer's capability of DNA methylation sequencing with a published non-invasive pancreatic cancer detection assay, using NovaSeq6000 as the benchmark.

RESULTS

We sequenced a series of synthetic cell-free DNA (cfDNA) samples with different tumor fractions and found MGISEQ-2000 yielded data with similar quality as NovaSeq6000. The methylation levels measured by MGISEQ-2000 demonstrated high consistency with NovaSeq6000. Moreover, MGISEQ-2000 showed a comparable analytic sensitivity with NovaSeq6000, suggesting its potential for clinical detection. As to evaluate the clinical performance of MGISEQ-2000, we sequenced 24 clinical samples and predicted the pathology of the samples with a clinical diagnosis model, PDACatch classifier. The clinical model performance of MGISEQ-2000's data was highly consistent with that of NovaSeq6000's data, with the area under the curve of 1. We also tested the model's robustness with MGISEQ-2000's data when reducing the sequencing depth. The results showed that MGISEQ-2000's data showed matching robustness of the PDACatch classifier with NovaSeq6000's data.

CONCLUSIONS

Taken together, MGISEQ-2000 demonstrated similar data quality, consistency of the methylation levels, comparable analytic sensitivity, and matching clinical performance, supporting its application in future non-invasive early cancer detection investigations by detecting distinct methylation patterns of cfDNAs.

Characteristics of the Fecal Microbiome of Piglets with Diarrhea Identified Using Shotgun Metagenomics Sequencing

Diarrhea in piglets is one of the most common diseases leading to high mortality and, as a result, to economic losses. Shotgun metagenomic sequencing was performed on the DNBSEQ-G50, MGI system to study the role of the fecal microbiome in the development of diarrhea in newborn piglets. Analysis of the study data showed that the composition of the fecal microbiome at the level of bacteria and fungi did not differ in piglets with diarrhea from the healthy group. Bacteria belonging to the phyla Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, and Fusobacteria were the most abundant. However, a higher level of bacterial alpha diversity was observed in the group of piglets with diarrhea, which may be due to dysbacteriosis and inflammation. The study of the virome showed the difference between the two types of phages: Bacteroides B40-8 prevailed in diseased piglets, while Escherichia virus BP4 was found in greater numbers in healthy piglets. The results of our study suggest that the association between the fecal microbiome and susceptibility to diarrhea in suckling piglets may have been previously overestimated.

Trypanosoma cruzi dysregulates expression profile of piRNAs in primary human cardiac fibroblasts during early infection phase

Trypanosoma cruzi, the etiological agent of Chagas Disease, causes severe morbidity, mortality, and economic burden worldwide. Though originally endemic to Central and South America, globalization has led to increased parasite presence in most industrialized countries. About 40% of infected individuals will develop cardiovascular, neurological, and/or gastrointestinal pathologies. Accumulating evidence suggests that the parasite induces alterations in host gene expression profiles in order to facilitate infection and pathogenesis. The role of regulatory gene expression machinery during T. cruzi infection, particularly small noncoding RNAs, has yet to be elucidated. In this study, we aim to evaluate dysregulation of a class of sncRNAs called piRNAs during early phase of T. cruzi infection in primary human cardiac fibroblasts by RNA-Seq. We subsequently performed in silico analysis to predict piRNA-mRNA interactions. We validated the expression of these selected piRNAs and their targets during early parasite infection phase by stem loop qPCR and qPCR, respectively. We found about 26,496,863 clean reads (92.72%) which mapped to the human reference genome. During parasite challenge, 441 unique piRNAs were differentially expressed. Of these differentially expressed piRNAs, 29 were known and 412 were novel. In silico analysis showed several of these piRNAs were computationally predicted to target and potentially regulate expression of genes including SMAD2, EGR1, ICAM1, CX3CL1, and CXCR2, which have been implicated in parasite infection, pathogenesis, and various cardiomyopathies. Further evaluation of the function of these individual piRNAs in gene regulation and expression will enhance our understanding of early molecular mechanisms contributing to infection and pathogenesis. Our findings here suggest that piRNAs play important roles in infectious disease pathogenesis and can serve as potential biomarkers and therapeutic targets.

miR-383-5p, miR-181a-5p, and miR-181b-5p as Predictors of Response to First-Generation Somatostatin Receptor Ligands in Acromegaly

Acromegaly is a chronic systemic disease caused in the vast majority of cases by growth hormone (GH)-secreting adenoma, with surgery being the first-line treatment. When a cure is not attained with surgery, first-generation somatostatin receptor ligands (fg-SRLs) are the most common medication prescribed. Predictors of response to fg-SRLs have been studied; however, they cannot fully predict the response to fg-SRL. MicroRNAs are small RNAs, the main role of which is messenger RNA (mRNA) post-transcriptional regulation. This study aimed to identify the microRNAs involved in resistance to treatment with fg-SRLs in acromegaly. Ten patients with acromegaly undergoing treatment with fg-SRLs were selected to undergo miRNA sequencing: five controlled and five uncontrolled with treatment. Bioinformatic analysis was performed to detect differentially expressed miRNAs. Then, the same 10 samples were used for validation by qPCR and an additional 22 samples were analyzed, totaling 32 samples. e We found 59 differentially expressed miRNAs in the first analysis. miR-181a-5p and miR-181b-5p were downregulated, and miR-383-5p was upregulated in the uncontrolled group. Receiver operating characteristic (ROC) curve analysis of miR-383-5p showed an NPV of 84.3% and a PPV of 84.5%. In summary, miR-181a-5p, miR-181b-5p, and miR-383-5p are biomarkers of response to fg-SRLs, and they can be used individually or included in prediction models as tools to guide clinical decisions.

A combined miRNA-piRNA signature in the serum and urine of rabbits infected with Toxoplasma gondii oocysts

BACKGROUND

Increasing evidence has shown that non-coding RNA (ncRNA) molecules play fundamental roles in cells, and many are stable in body fluids as circulating RNAs. Study on these ncRNAs will provide insights into toxoplasmosis pathophysiology and/or help reveal diagnostic biomarkers.

METHODS

We performed a high-throughput RNA-Seq study to comprehensively profile the microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs) in rabbit serum and urine after infection with Toxoplasma gondii oocysts during the whole infection process.

RESULTS

Total RNA extracted from serum and urine samples of acutely infected [8 days post-infection (DPI)], chronically infected (70 DPI) and uninfected rabbits were subjected to genome-wide small RNA sequencing. We identified 2089 miRNAs and 2224 novel piRNAs from the rabbit sera associated with T. gondii infection. Meanwhile, a total of 518 miRNAs and 4182 novel piRNAs were identified in the rabbit urine associated with T. gondii infection. Of these identified small ncRNAs, 1178 and 1317 serum miRNAs and 311 and 294 urine miRNAs were identified as differentially expressed (DE) miRNAs in the acute and chronic stages of infections, respectively. A total of 1748 and 1814 serum piRNAs and 597 and 708 urine piRNAs were found in the acute and chronic infection stages, respectively. Of these dysregulated ncRNAs, a total of 88 common DE miRNAs and 120 DE novel piRNAs were found in both serum and urine samples of infected rabbits.

CONCLUSIONS

These findings provide valuable data for revealing the physiology of herbivore toxoplasmosis caused by oocyst infection. Circulating ncRNAs identified in this study are potential novel diagnostic biomarkers for the detection/diagnosis of toxoplasmosis in herbivorous animals.

The type-B response regulators ARR10, ARR12, and ARR18 specify the central cell in Arabidopsis

In Arabidopsis thaliana, the female gametophyte consists of two synergid cells, an egg cell, a diploid central cell, and three antipodal cells. CYTOKININ INDEPENDENT 1 (CKI1), a histidine kinase constitutively activating the cytokinin signaling pathway, specifies the central cell and restricts the egg cell. However, the mechanism regulating CKI1-dependent central cell specification is largely unknown. Here, we showed that the type-B ARABIDOPSIS RESPONSE REGULATORS10, 12, and 18 (ARR10/12/18) localize at the chalazal pole of the female gametophyte. Phenotypic analysis showed that the arr10 12 18 triple mutant is female sterile. We examined the expression patterns of embryo sac marker genes and found that the embryo sac of arr10 12 18 plants had lost central cell identity, a phenotype similar to that of the Arabidopsis cki1 mutant. Genetic analyses demonstrated that ARR10/12/18, CKI1, and ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN2, 3, and 5 (AHP2/3/5) function in a common pathway to regulate female gametophyte development. In addition, constitutively activated ARR10/12/18 in the cki1 embryo sac partially restored the fertility of cki1. Results of transcriptomic analysis supported the conclusion that ARR10/12/18 and CKI1 function together to regulate the identity of the central cell. Our results demonstrated that ARR10/12/18 function downstream of CKI1-AHP2/3/5 as core factors to determine cell fate of the female gametophyte.

Parental transfer of an antibiotic mixture induces cardiotoxicity in early life-stage zebrafish: A cross-generational study

Antibiotic residues in the aquatic environment have been shown to induce significant adverse effects on the early-life stage development of aquatic organisms, though the underlying molecular mechanisms of these effects have not been well characterized. In this study, we performed global mRNA-miRNA sequencing, canonical pathway analyses, morphological, physiological, immunohistochemical, and behavioral analyses to comprehensively assess the cross-generational cardiotoxicity and mechanisms of antibiotic mixtures in zebrafish. Following parental treatment to 1 and 100 μg/L antibiotic mixtures (15 of the most commonly detected antibiotics) for 150 days, all 15 assessed antibiotics were detected in the F1 eggs, indicating the cross-generational transfer of antibiotics. Global mRNA-miRNA sequencing functional analysis predicted cardiotoxicity in the F1 generation by using the F1 whole fish. Consistent with canonical pathway analyses, significant cardiotoxicity was observed in F1 larvae, as well as the apoptosis of cardiac cells. Furthermore, let-7a-5p regulated the cardiac hypertrophy signaling pathway, suggesting mechanisms of miRNA of let-7 family mediating cross-generational cardiotoxicity of antibiotics in zebrafish. This study lays some groundwork for developing interventions to prevent parental exposure to environmental pollutants such as antibiotics from adversely affecting offspring development.

Relationship between CYP2C19 Polymorphism and Clopidogrel Resistance in Patients with Coronary Heart Disease and Ischemic Stroke in China

Objective

Clopidogrel is widely used for preventing ischemic complications related to cardiovascular diseases. However, many patients experience clopidogrel resistance (CR). The polymorphisms of CYP2C19 have been implicated in CR, but CYP2C19 polymorphism considerably varies with both ethnic group and geographical location. This study aimed to investigate the association between CYP2C19 polymorphisms and clopidogrel resistance (CR) in patients with coronary heart disease and ischemic stroke among Han and Tibetan populations in Qinghai Province, China.

Methods

From June 2019 to January 2020, patients who were diagnosed with coronary heart disease or cerebral infarction in internal medicine of Qinghai Provincial People's Hospital and had taken dual antiplatelet drugs were included in this study. Blood was collected and routine items were completed. Whole exome sequencing was performed for CYP2C19 genetic polymorphisms of CYP2C19∗2 (rs4244285), CYP2C19∗3 (rs4986893), and CYP2C19∗17 (rs12248560).

Results

A total of 91 patients with coronary heart disease or cerebral infarction (67 Han people (65.99 ± 12.25 years old) and 24 Tibetan (63.6324 Tib years old)) including 52 cases with CR and 39 cases with non-CR were enrolled in this study. For the Han population, the differences in age, glycosylated hemoglobin, activated partial thromboplastin time (APTT), gender, aspirin resistance, and diabetes were significant between the CR and non-CR groups. For the Tibetan population, the two groups showed no significant difference in all indicators. There was no significant difference between CR and non-CR groups for all genotypes (CYP2C19 ∗2, ∗3, and ∗17) in either Han or Tibetan populations. For the Han populations, age, APTT, and aspirin resistance were significantly correlated with CR.

Conclusion

The present study indicated that CYP2C19∗2, CYP2C19∗3, and CYP2C19∗17 alleles were not correlated with CR for both Han and Tibetan populations in Qinghai Province, while age, APTT, and aspirin resistance were independent risk factors of CR in this region.

A Comprehensive Characterization of Small RNA Profiles by Massively Parallel Sequencing in Six Forensic Body Fluids/Tissue

Body fluids/tissue identification (BFID) is an essential procedure in forensic practice, and RNA profiling has become one of the most important methods. Small non-coding RNAs, being expressed in high copy numbers and resistant to degradation, have great potential in BFID but have not been comprehensively characterized in common forensic stains. In this study, the miRNA, piRNA, snoRNA, and snRNA were sequenced in 30 forensic relevant samples (menstrual blood, saliva, semen, skin, venous blood, and vaginal secretion) using the BGI platform. Based on small RNA profiles, relative specific markers (RSM) and absolute specific markers (ASM) were defined, which can be used to identify a specific body fluid/tissue out of two or six, respectively. A total of 5204 small RNAs were discovered including 1394 miRNAs (including 236 novel miRNA), 3157 piRNAs, 636 snoRNAs, and 17 snRNAs. RSMs for 15 pairwise body fluid/tissue groups were discovered by differential RNA analysis. In addition, 90 ASMs that were specifically expressed in a certain type of body fluid/tissue were screened, among them, snoRNAs were reported first in forensic genetics. In brief, our study deepened the understanding of small RNA profiles in forensic stains and offered potential BFID markers that can be applied in different forensic scenarios.

Vaginal microbiota and personal risk factors associated with HPV status conversion—A new approach to reduce the risk of cervical cancer?

Vaginal microbiota (VMB) is associated with changes in Human papilloma virus (HPV) status, which consequently influences the risk of cervical cancer. This association was often confounded by personal risk factors. This pilot research aimed to explore the relationship between vaginal microbiota, personal risk factors and their interactions with HPV status conversion to identify the vaginal microbiota that was associated with HPV clearance under heterogeneous personal risk factors. A total of 38 women participated by self-collecting a cervicovaginal mucus (CVM) sample that was sent for metagenomics sequencing. Most of the participants also filled in personal risk factors questionnaire through an eHealth platform and authorized the use of their previous HPV genotyping results stored in this eHealth platform. Based on the two HPV results, the participants were grouped into three cohorts, namely HPV negative, HPV persistent infection, and HPV status conversion. The relative abundance of VMB and personal factors were compared among these three cohorts. A correlation investigation was performed between VMB and the significant personal factors to characterize a robustness of the panel for HPV status change using R programming. At baseline, 12 participants were HPV-negative, and 22 were HPV-positive. Within one year, 18 women remained HPV-positive, 12 were HPV-negative and 4 participants showed HPV clearance. The factors in the eHealth questionnaire were systematically evaluated which identified several factors significantly associated with persistent HPV infection, including age, salary, history of reproductive tract infection, and the total number of sexual partners. Concurrent vaginal microbiome samples suggest that a candidate biomarker panel consisting of Lactobacillus gasseri, Streptococcus agalactiae, and Timona prevotella bacteria, which may be associated with HPV clearance. This pilot study indicates a stable HPV status-related vaginal microbe environment. To establish a robust biomarker panel for clinical use, larger cohorts will be recruited into follow-up studies.

Integrated Full-Length Transcriptome and MicroRNA Sequencing Approaches Provide Insights Into Salt Tolerance in Mangrove (Sonneratia apetala Buch.-Ham.)

MicroRNAs (miRNAs) are small RNA molecules that serve as key players in plant stress responses. Although stress-regulated miRNAs have been explored in various plants, they are not well studied in mangroves. Herein, we combined PacBio isoform sequencing (Iso-Seq) with BGISEQ short-read RNA-seq to probe the role of miRNAs in the salt stress response of the mangrove plant, Sonneratia apetala Buch.-Ham. A total of 1,702,463 circular consensus sequencing reads were generated that produced 295,501 nonredundant full-length transcripts from the leaves of a 1-year-old S. apetala. After sequencing nine small RNA libraries constructed from control and 1- and 28-day 300 mM NaCl treatments, we identified 143 miRNAs (114 known and 29 novel) from a total of >261 million short reads. With the criteria of |log2FC| ≥ 1 and q-value < 0.05, 42 and 70 miRNAs were differentially accumulated after 1- and 28-day salt treatments, respectively. These differential accumulated miRNAs potentially targeted salt-responsive genes encoding transcription factors, ion homeostasis, osmotic protection, and detoxificant-related proteins, reminiscent of their responsibility for salinity adaptation in S. apetala. Particularly, 62 miRNAs were Sonneratia specific under salt stress, of which 34 were co-expressed with their 131 predicted targets, thus producing 140 miRNA-target interactions. Of these, 82 miRNA-target pairs exhibited negative correlations. Eighteen miRNA targets were categorized for the 'environmental information processing' during KEGG analysis and were related to plant hormone signal transduction (ko04075), MAPK signaling pathway-plant (ko04016), and ABC transporters (ko02010). These results underscored miRNAs as possible contributors to mangrove success in severe environments and offer insights into an miRNA-mediated regulatory mechanism of salt response in S. apetala.

Benchmarking of ATAC Sequencing Data From BGI’s Low-Cost DNBSEQ-G400 Instrument for Identification of Open and Occupied Chromatin Regions

Background: Chromatin falls into one of two major subtypes: closed heterochromatin and euchromatin which is accessible, transcriptionally active, and occupied by transcription factors (TFs). The most widely used approach to interrogate differences in the chromatin state landscape is the Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq). While library generation is relatively inexpensive, sequencing depth requirements can make this assay cost-prohibitive for some laboratories.

Findings: Here, we benchmark data from Beijing Genomics Institute’s (BGI) DNBSEQ-G400 low-cost sequencer against data from a standard Illumina instrument (HiSeqX10). For comparisons, the same bulk ATAC-seq libraries generated from pluripotent stem cells (PSCs) and fibroblasts were sequenced on both platforms. Both instruments generate sequencing reads with comparable mapping rates and genomic context. However, DNBSEQ-G400 data contained a significantly higher number of small, sub-nucleosomal reads (>30% increase) and a reduced number of bi-nucleosomal reads (>75% decrease), which resulted in narrower peak bases and improved peak calling, enabling the identification of 4% more differentially accessible regions between PSCs and fibroblasts. The ability to identify master TFs that underpin the PSC state relative to fibroblasts (via HOMER, HINT-ATAC, TOBIAS), namely, foot-printing capacity, were highly similar between data generated on both platforms. Integrative analysis with transcriptional data equally enabled direct recovery of three published 3-factor combinations that have been shown to induce pluripotency.

Conclusion: Other than a small increase in peak calling sensitivity for DNBSEQ-G400 data (BGI), both platforms enable comparable levels of open chromatin identification for ATAC-seq library sequencing, yielding similar analytical outcomes, albeit at low-data generation costs in the case of the BGI instrument.

Nano2NGS-Muta: a framework for converting nanopore sequencing data to NGS-liked sequencing data for hotspot mutation detection

Nanopore sequencing, also known as single-molecule real-time sequencing, is a third/fourth generation sequencing technology that enables deciphering single DNA/RNA molecules without the polymerase chain reaction. Although nanopore sequencing has made significant progress in scientific research and clinical practice, its application has been limited compared with next-generation sequencing (NGS) due to specific design principle and data characteristics, especially in hotspot mutation detection. Therefore, we developed Nano2NGS-Muta as a data analysis framework for hotspot mutation detection based on long reads from nanopore sequencing. Nano2NGS-Muta is characterized by applying nanopore sequencing data to NGS-liked data analysis pipelines. Long reads can be converted into short reads and then processed through existing NGS analysis pipelines in combination with statistical methods for hotspot mutation detection. Nano2NGS-Muta not only effectively avoids false positive/negative results caused by non-random errors and unexpected insertions-deletions (indels) of nanopore sequencing data, improves the detection accuracy of hotspot mutations compared to conventional nanopore sequencing data analysis algorithms but also breaks the barriers of data analysis methods between short-read sequencing and long-read sequencing. We hope Nano2NGS-Muta can serves as a reference method for nanopore sequencing data and promotes higher application scope of nanopore sequencing technology in scientific research and clinical practice.

Mechanism of Sugarbeet Seed Germination Enhanced by Hydrogen Peroxide

Seed germination is a critical first stage of plant development but can be arrested by factors including dormancy and environmental conditions. Strategies to enhance germination are of interest to plant breeders to ensure the ability to utilize the genetic potential residing inside a dormant seed. In this study, seed germination in two sugarbeet (Beta vulgaris ssp. vulgaris L.) lines F1004 and F1015 through incubating seeds in hydrogen peroxide (H₂O₂) solution was improved over 70% relative to germinating seeds through water incubation. It was further found that low germination from water incubation was caused by physical dormancy in F1015 seeds with initial seed imbibition blocked by the seed pericarp, and physiological dormancy in F1004 seeds with germination compromised due to the physiological condition of the embryo. To identify genes that are differentially expressed in response to cellular activities promoted by H₂O₂ during overcoming different type of dormancies, an RNA-Seq study was carried out and found H₂O₂ treatment during germination accelerated the degradation of seed stored mRNAs that were synthesized before or during seed storage to provide protections and maintain the dormant state. Comparison of transcripts in H₂O₂-treated seeds between the two sugarbeet lines identified differentially expressed genes (DEGs) that were higher in F1004 for alleviating physiological dormancy were known to relative to gene expression regulation. The research established that H₂O₂ overcomes both physical and physiological dormancies by hastening the transition of seeds from dormancy into germination. More DEGs related to gene expression regulation were involved in relieving physiological dormancy which provides new knowledge about the role of exogenous H₂O₂ as a signaling molecule for regulating gene activities during germination. Moreover, the protocol using H₂O₂ to promote germination will be useful for rescuing plant germplasms with poor germination.

Safflower oil body nanoparticles deliver hFGF10 to hair follicles and reduce microinflammation to accelerate hair regeneration in androgenetic alopecia

Androgenetic alopecia (AGA) affects physical and mental health with limited therapeutic options. Novel materials and delivery methods have considerable potential to improve the current paradigm of treatment. In this study, we used a novel plant nanoparticle of safflower oil body (SOB) loaded with human fibroblast growth factor 10 (hFGF10) to target hair follicles and accelerate hair regeneration in AGA mice with few adverse effects. Our data revealed that the average particle size of SOB-hFGF10 was 226.73 ± 9.98 nm, with a spherical and uniform structure, and that SOB-hFGF10 was quicker to preferentially penetrate into hair follicles than hFGF2 alone. Using a mouse model of AGA, SOB-hFGF10 was found to significantly improve hair regeneration without any significant toxicity. Furthermore, SOB-hFGF10 inhibited dihydrotestosterone (DHT)-induced TNF-α, IL-1β, and IL-6 overproduction in macrophages in relation to hair follicle microinflammation, thereby enhancing the proliferation of dermal papilla cells. Overall, this study provides an applicable therapeutic method through targeting hair follicles and reducing microinflammation to accelerate hair regeneration in AGA.

System analysis of the sequencing quality of human whole exome samples on BGI NGS platform

Human exome sequencing is a classical method used in most medical genetic applications. The leaders in the field are the manufacturers of enrichment kits based on hybridization of cRNA or cDNA biotinylated probes specific for a genomic region of interest. Recently, the platforms manufactured by the Chinese company MGI Tech have become widespread in Europe and Asia. The reliability and quality of the obtained data are already beyond any doubt. However, only a few kits compatible with these sequencers can be used for such specific tasks as exome sequencing. We developed our own solution for library pre-capture pooling and exome enrichment with Agilent probes. In this work, using a set of the standard benchmark samples from the Platinum Genome collection, we demonstrate that the qualitative and quantitative parameters of our protocol which we called "RSMU_exome" exceed those of the MGI Tech kit. Our protocol allows for identifying more SNV and indels, generates fewer PCR duplicates, enables pooling of more samples in a single enrichment procedure, and requires less raw data to obtain results comparable with the MGI Tech's protocol. The cost of our protocol is also lower than that of MGI Tech's solution.

Evaluation of the MGISEQ-2000 Sequencing Platform for Illumina Target Capture Sequencing Libraries

Illumina is the leading sequencing platform in the next-generation sequencing (NGS) market globally. In recent years, MGI Tech has presented a series of new sequencers, including DNBSEQ-T7, MGISEQ-2000 and MGISEQ-200. As a complex application of NGS, cancer-detecting panels pose increasing demands for the high accuracy and sensitivity of sequencing and data analysis. In this study, we used the same capture DNA libraries constructed based on the Illumina protocol to evaluate the performance of the Illumina Nextseq500 and MGISEQ-2000 sequencing platforms. We found that the two platforms had high consistency in the results of hotspot mutation analysis; more importantly, we found that there was a significant loss of fragments in the 101-133 bp size range on the MGISEQ-2000 sequencing platform for Illumina libraries, but not for the capture DNA libraries prepared based on the MGISEQ protocol. This phenomenon may indicate fragment selection or low fragment ligation efficiency during the DNA circularization step, which is a unique step of the MGISEQ-2000 sequence platform. In conclusion, these different sequencing libraries and corresponding sequencing platforms are compatible with each other, but protocol and platform selection need to be carefully evaluated in combination with research purpose.

Control of osteocyte dendrite formation by Sp7 and its target gene osteocrin

Some osteoblasts embed within bone matrix, change shape, and become dendrite-bearing osteocytes. The circuitry that drives dendrite formation during "osteocytogenesis" is poorly understood. Here we show that deletion of Sp7 in osteoblasts and osteocytes causes defects in osteocyte dendrites. Profiling of Sp7 target genes and binding sites reveals unexpected repurposing of this transcription factor to drive dendrite formation. Osteocrin is a Sp7 target gene that promotes osteocyte dendrite formation and rescues defects in Sp7-deficient mice. Single-cell RNA-sequencing demonstrates defects in osteocyte maturation in the absence of Sp7. Sp7-dependent osteocyte gene networks are associated with human skeletal diseases. Moreover, humans with a SP7R316C mutation show defective osteocyte morphology. Sp7-dependent genes that mark osteocytes are enriched in neurons, highlighting shared features between osteocytic and neuronal connectivity. These findings reveal a role for Sp7 and its target gene Osteocrin in osteocytogenesis, revealing that pathways that control osteocyte development influence human bone diseases.

Characterization and target gene analysis of microRNAs in the antennae of the parasitoid wasp Microplitis mediator

MicroRNAs (miRNAs), a class of non-coding single-strand RNA molecules encoded by endogenous genes, are about 21-24 nucleotides long and are involved in the post-transcriptional regulation of gene expression in plants and animals. Generally, the types and quantities of miRNAs in the different tissues of an organism are diverse, and these divergences may be related to their specific functions. Here we have identified 296 known miRNAs and 46 novel miRNAs in the antennae of the parasitoid wasp Microplitis mediator by high-throughput sequencing. Thirty-three miRNAs were predicted to target olfactory-associated genes, including odorant binding proteins (OBPs), chemosensory proteins, odorant receptors (ORs), ionotropic receptors (IRs) and gustatory receptors. Among these, 17 miRNAs were significantly highly expressed in the antennae, four miRNAs were highly expressed both in the antennae and head or wings, while the remaining 12 miRNAs were mainly expressed in the head, thorax, abdomen, legs and wings. Notably, miR-9a-5p and miR-2525-3p were highly expressed in male antennae, whereas miR-1000-5p and novel-miR-13 were enriched in female antennae. The 17 miRNAs highly expressed in antennae are likely to be associated with olfaction, and were predicted to target one OBP (targeted by miR-3751-3p), one IR (targeted by miR-7-5p) and 14 ORs (targeted by 15 miRNAs including miR-6-3p, miR-9a-5p, miR-9b-5p, miR-29-5p, miR-71-5p, miR-275-3p, miR-1000-5p, miR-1000-3p, miR-2525-3p, miR-6012-3p, miR-9719-3p, novel-miR-10, novel-miR-13, novel-miR-14 and novel-miR-28). These candidate olfactory-associated miRNAs are all likely to be involved in chemoreception through the regulation of chemosensory gene expression in the antennae of M. mediator.

Differential RNA packaging into small extracellular vesicles by neurons and astrocytes

BACKGROUND

Small extracellular vesicles (sEVs) mediate intercellular communication by transferring RNA, proteins, and lipids to recipient cells. These cargo molecules are selectively loaded into sEVs and mirror the physiological state of the donor cells. Given that sEVs can cross the blood-brain barrier and their composition can change in neurological disorders, the molecular signatures of sEVs in circulation can be potential disease biomarkers. Characterizing the molecular composition of sEVs from different cell types is an important first step in determining which donor cells contribute to the circulating sEVs.

METHODS

Cell culture supernatants from primary mouse cortical neurons and astrocytes were used to purify sEVs by differential ultracentrifugation and sEVs were characterized using nanoparticle tracking analysis, transmission electron microscopy and western blot. RNA sequencing was used to determine differential expression and loading patterns of miRNAs in sEVs released by primary neurons and astrocytes. Motif analysis was conducted on enriched miRNAs in sEVs and their respective donor cells.

RESULTS

Sequencing total cellular RNA, and miRNAs from sEVs isolated from culture media of postnatal mouse cortical neurons and astrocytes revealed a distinct profile between sEVs and their corresponding cells. Though the total number of detected miRNAs in astrocytes was greater than neurons, neurons expressed more sEV-associated miRNAs than astrocytes. Only 20.7% of astrocytic miRNAs were loaded into sEVs, while 41.0% of neuronal miRNAs were loaded into sEVs, suggesting differences in the cellular sorting mechanisms. We identified short RNA sequence motifs, or EXOmotifs, on the miRNAs that were differentially loaded or excluded from sEVs. A sequence motif GUAC was enriched in astrocytic sEVs. miRNAs preferably retained in neurons or astrocytes had a similar RNA motif CACACA, suggesting a cell-type-independent mechanism to maintain cellular miRNAs. mRNAs of five RNA-binding proteins associated with passive or active RNA sorting into sEVs were differentially expressed between neurons and astrocytes, one of which, major vault protein was higher in astrocytes than in neurons and detected in astrocytic sEVs.

CONCLUSIONS

Our studies suggest differences in RNA sorting into sEVs. These differences in miRNA signatures can be used for determining the cellular sources of sEVs altered in neurological disorders. Video abstract.

A SNP of HD-ZIP I transcription factor leads to distortion of trichome morphology in cucumber (Cucumis sativus L.)

BACKGROUND

Trichomes are excellent model systems for the analysis of cell differentiation and play essential roles in plant protection. From cucumber inbred line 'WD1', we identified an EMS-induced trichome abnormally developing mutant, nps, which exhibited smaller, denser and no pyramid-shaped head trichomes.

RESULTS

Using F₂ and BC₁ populations constructed from a cross between nps and '9930', the genetic analysis showed that the nps trait is controlled by a single recessive nuclear gene. We identified CsNps by map-based cloning with 576 individuals of the F₂ population generated from the cross of nps and inbred line '9930'. The CsNps was located at a 13.4-kb genomic region on chromosome 3, which region contains three predicted genes. Sequence analysis showed that only one single nucleotide mutation (C → T) between 9930 and nps was found in the second exon of Csa3G748220, a plant-specific class I HD-Zip gene. The result of allelism test also indicated that nps is a novel allelic mutant of Mict (Micro-trichome). Thus, nps was renamed mict-L130F. By comparing the transcriptome of mict-L130F vs WD1 and 06-2 (mict) vs 06-1 (wildtype, near-isogenic line of 06-2), several potential target genes that may be related to trichome development were identified.

CONCLUSIONS

Our results demonstrate that Mict-L130F is involved in the morphogenesis of trichomes. Map-based cloning of the Mict-L130F gene could promote the study of trichome development in cucumber.

Distinct miRNA Signatures and Networks Discern Fetal from Adult Erythroid Differentiation and Primary from Immortalized Erythroid Cells

MicroRNAs (miRNAs) are small non-coding RNAs crucial for post-transcriptional and translational regulation of cellular and developmental pathways. The study of miRNAs in erythropoiesis elucidates underlying regulatory mechanisms and facilitates related diagnostic and therapy development. Here, we used DNA Nanoball (DNB) small RNA sequencing to comprehensively characterize miRNAs in human erythroid cell cultures. Based on primary human peripheral-blood-derived CD34+ (hCD34+) cells and two influential erythroid cell lines with adult and fetal hemoglobin expression patterns, HUDEP-2 and HUDEP-1, respectively, our study links differential miRNA expression to erythroid differentiation, cell type, and hemoglobin expression profile. Sequencing results validated by reverse-transcription quantitative PCR (RT-qPCR) of selected miRNAs indicate shared differentiation signatures in primary and immortalized cells, characterized by reduced overall miRNA expression and reciprocal expression increases for individual lineage-specific miRNAs in late-stage erythropoiesis. Despite the high similarity of same-stage hCD34+ and HUDEP-2 cells, differential expression of several miRNAs highlighted informative discrepancies between both cell types. Moreover, a comparison between HUDEP-2 and HUDEP-1 cells displayed changes in miRNAs, transcription factors (TFs), target genes, and pathways associated with globin switching. In resulting TF-miRNA co-regulatory networks, major therapeutically relevant regulators of globin expression were targeted by many co-expressed miRNAs, outlining intricate combinatorial miRNA regulation of globin expression in erythroid cells.

The Setup and Application of Reference Material in Sequencing-Based Noninvasive Prenatal Testing

INTRODUCTION

The sequencing-based noninvasive prenatal testing (NIPT) has been successfully integrated into clinical practice and facilitated the early detection of fetal chromosomal anomalies. However, a comprehensive reference material to evaluate and quality control NIPT services from different NIPT providers remains unavailable.

METHODS

In this study, we established a set of NIPT reference material consisting of 192 simulated samples. Most of the potential factors influencing the accuracy of NIPT, such as fetal fraction, mosaicism, and interfering substances, were included in the reference material. We compared the performance of chromosomal abnormalities detection on 3 widely used sequencers (NextSeq 500, BGISEQ-500, and Ion Proton) based on the reference material.

RESULTS

All 3 sequencers provided highly accurate and reliable results to samples with ≥3.5% fetal fractions and high percentage of mosaicism.

CONCLUSIONS

The established reference material can serve as a universal standard quality control for the current and new-coming NIPT providers based on various sequencers.

Efficient and stable metabarcoding sequencing data using a DNBSEQ-G400 sequencer validated by comprehensive community analyses

Metabarcoding is a widely used method for fast characterization of microbial communities in complex environmental samples. However, the selction of sequencing platform can have a noticeable effect on the estimated community composition. Here, we evaluated the metabarcoding performance of a DNBSEQ-G400 sequencer developed by MGI Tech using 16S and internal transcribed spacer (ITS) markers to investigate bacterial and fungal mock communities, as well as the ITS2 marker to investigate the fungal community of 1144 soil samples, with additional technical replicates. We show that highly accurate sequencing of bacterial and fungal communities is achievable using DNBSEQ-G400. Measures of diversity and correlation from soil metabarcoding showed that the results correlated highly with those of different machines of the same model, as well as between different sequencing modes (single-end 400 bp and paired-end 200 bp). Moderate, but significant differences were observed between results produced with different sequencing platforms (DNBSEQ-G400 and MiSeq); however, the highest differences can be caused by selecting different primer pairs for PCR amplification of taxonomic markers. These differences suggested that care is needed while jointly analyzing metabarcoding data from differenet experiments. This study demonstrated the high performance and accuracy of DNBSEQ-G400 for short-read metabarcoding of microbial communities. Our study also produced datasets to allow further investigation of microbial diversity.

Exosome-mediated pyroptosis of miR-93-TXNIP-NLRP3 leads to functional difference between M1 and M2 macrophages in sepsis-induced acute kidney injury

Sepsis is a systemic inflammatory response syndrome caused by infection, resulting in organ dysfunction. Sepsis-induced acute kidney injury (AKI) is one of the most common potential complications. Increasing reports have shown that M1 and M2 macrophages both take part in the progress of AKI by influencing the level of inflammatory factors and the cell death, including pyroptosis. However, whether M1 and M2 macrophages regulate AKI by secreting exosome remains unknown. In the present study, we isolated the exosomes from M1 and M2 macrophages and used Western blot and enzyme-linked immunosorbent assay (ELISA) to investigate the effect of M1 and M2 exosomes on cell pyroptosis. miRNA sequencing was used to identify the different miRNA in M1 and M2 exosomes. Luciferase reporter assay was used to verify the target gene of miRNA. We confirmed that exosomes excreted by macrophages regulated cell pyroptosis in vitro by using Western blot and ELISA. miRNA sequencing revealed the differentially expressed level of miRNAs in M1 and M2 exosomes, among which miR-93-5p was involved in the regulation of pyroptosis. By using bioinformatics predictions and luciferase reporter assay, we found that thioredoxin-interacting protein (TXNIP) was a direct target of miR-93-5p. Further in vitro and in vivo experiments indicated that exosomal miR-93-5p regulated the TXNIP directly to influence the pyroptosis in renal epithelial cells, which explained the functional difference between different phenotypes of macrophages. This study might provide new targets for the treatment of sepsis-induced AKI.

Developmental validation of the MGIEasy Signature Identification Library Prep Kit, an all-in-one multiplex system for forensic applications

Analyzing genetic markers in nuclear and mitochondrial genomes is helpful in various forensic applications, such as individual identifications and kinship analyses. However, most commercial kits detect these markers separately, which is time-consuming, laborious, and more error-prone (mislabelling, contamination, ...). The MGIEasy Signature Identification Library Prep Kit (hereinafter "MGIEasy identification system"; MGI Tech, Shenzhen, China) has been designed to provide a simple, fast, and robust way to detect appropriate markers in one multiplex PCR reaction: 52 autosomal STRs, 27 X-chromosomal STRs, 48 Y-chromosomal STRs, 145 identity-informative SNPs, 53 ancestry-informative SNPs, 29 phenotype-informative SNPs, and the hypervariable regions of mitochondrial DNA (mtDNA). Here, we validated the performance of MGIEasy identification system following the guidelines of the Scientific Working Group on DNA Analysis Methods (SWGDAM), assessing species specificity, sensitivity, mixture identification, stability under non-optimal conditions (degraded samples, inhibitor contamination, and various substrates), repeatability, and concordance. Libraries prepared using MGIEasy identification system were sequenced on a MGISEQ-2000 instrument (MGI Tech). MGIEasy-derived STR, SNP, and mtDNA genotypes were highly concordant with CE-based STR genotypes (99.79%), MiSeq FGx-based SNP genotypes (99.78%), and Sanger-based mtDNA genotypes (100%), respectively. This system was strongly human-specific, resistant to four common PCR inhibitors, and reliably amplified both low quantities of DNA (as low as 0.125 ng) and degraded DNA (~ 150 nt). Most of the unique alleles from the minor contributor were detected in 1:10 male-female and male-male mixtures; some minor Y-STR alleles were even detected in 1:1000 male-female mixtures. MGIEasy also successfully directly amplified markers from blood stains on FTA cards, filter papers, and swabs. Thus, our results demonstrated that MGIEasy identification system was suitable for use in forensic analyses due to its robust and reliable performance on samples of varying quality and quantity.

Sharing genetic variants with the NGS pipeline is essential for effective genomic data sharing and reproducibility in health information exchange

Genetic variants causing underlying pharmacogenetic and disease phenotypes have been used as the basis for clinical decision-making. However, due to the lack of standards for next-generation sequencing (NGS) pipelines, reproducing genetic variants among institutions is still difficult. The aim of this study is to show how many important variants for clinical decisions can be individually detected using different pipelines. Genetic variants were derived from 105 breast cancer patient target DNA sequences via three different variant-calling pipelines. HaplotypeCaller, Mutect2 tumor-only mode in the Genome Analysis ToolKit (GATK), and VarScan were used in variant calling from the sequence read data processed by the same NGS preprocessing tools using Variant Effect Predictor. GATK HaplotypeCaller, VarScan, and MuTect2 found 25,130, 16,972, and 4232 variants, comprising 1491, 1400, and 321 annotated variants with ClinVar significance, respectively. The average number of ClinVar significant variants in the patients was 769.43, 16.50% of the variants were detected by only one variant caller. Despite variants with significant impact on clinical decision-making, the detected variants are different for each algorithm. To utilize genetic variants in the clinical field, a strict standard for NGS pipelines is essential.

CoolMPS: evaluation of antibody labeling based massively parallel non-coding RNA sequencing

Results of massive parallel sequencing-by-synthesis vary depending on the sequencing approach. CoolMPS™ is a new sequencing chemistry that incorporates bases by labeled antibodies. To evaluate the performance, we sequenced 240 human non-coding RNA samples (dementia patients and controls) with and without CoolMPS. The Q30 value as indicator of the per base sequencing quality increased from 91.8 to 94%. The higher quality was reached across the whole read length. Likewise, the percentage of reads mapping to the human genome increased from 84.9 to 86.2%. For both technologies, we computed similar distributions between different RNA classes (miRNA, piRNA, tRNA, snoRNA and yRNA) and within the classes. While standard sequencing-by-synthesis allowed to recover more annotated miRNAs, CoolMPS yielded more novel miRNAs. The correlation between the two methods was 0.97. Evaluating the diagnostic performance, we observed lower minimal P-values for CoolMPS (adjusted P-value of 0.0006 versus 0.0004) and larger effect sizes (Cohen's d of 0.878 versus 0.9). Validating 19 miRNAs resulted in a correlation of 0.852 between CoolMPS and reverse transcriptase-quantitative polymerase chain reaction. Comparison to data generated with Illumina technology confirmed a known shift in the overall RNA composition. With CoolMPS we evaluated a novel sequencing-by-synthesis technology showing high performance for the analysis of non-coding RNAs.

Trypanosoma cruzi Modulates PIWI-Interacting RNA Expression in Primary Human Cardiac Myocytes during the Early Phase of Infection

Trypanosoma cruzi dysregulates the gene expression profile of primary human cardiomyocytes (PHCM) during the early phase of infection through a mechanism which remains to be elucidated. The role that small non-coding RNAs (sncRNA) including PIWI-interacting RNA (piRNA) play in regulating gene expression during the early phase of infection is unknown. To understand how T. cruzi dysregulate gene expression in the heart, we challenged PHCM with T. cruzi trypomastigotes and analyzed sncRNA, especially piRNA, by RNA-sequencing. The parasite induced significant differential expression of host piRNAs, which can target and regulate the genes which are important during the early infection phase. An average of 21,595,866 (88.40%) of clean reads mapped to the human reference genome. The parasite induced 217 unique piRNAs that were significantly differentially expressed (q ≥ 0.8). Of these differentially expressed piRNAs, 6 were known and 211 were novel piRNAs. In silico analysis showed that some of the dysregulated known and novel piRNAs could target and potentially regulate the expression of genes including NFATC2, FOS and TGF-β1, reported to play important roles during T. cruzi infection. Further evaluation of the specific functions of the piRNAs in the regulation of gene expression during the early phase of infection will enhance our understanding of the molecular mechanism of T. cruzi pathogenesis. Our novel findings constitute the first report that T. cruzi can induce differential expression of piRNAs in PHCM, advancing our knowledge about the involvement of piRNAs in an infectious disease model, which can be exploited for biomarker and therapeutic development.

RNA-seq identifies circulating miRNAs as potential biomarkers for plaque rupture in patients with ST-segment elevation myocardial infarction

BACKGROUND

Plaque rupture (PR) and plaque erosion (PE) are the two major pathological phenotypes in acute coronary syndrome. Since microRNAs have been found to be involved in the mechanisms of PR and PE, we investigated the diagnostic utility of microRNAs in differentiating between patients with PR and patients with PE.

METHODS

MicroRNA sequencing was performed on plasma from 21 patients with PR, 20 patients with PE and 17 healthy control subjects (HCs). 24 miRNAs were selected for validation in 20 PR patients and 20 PE patients and 8 miRNAs were further validated in an independent replication cohort (82 patients with PR, 84 patients with PE and 59 HCs) by applying quantitative real-time polymerase chain reaction. Then we analyzed pathways associated with significant miRNAs in PR.

RESULTS

MiR-744-3p, miR-324-3p and miR-330-3p were significantly upregulated in the PR group compared with the PE group (Log₁₀miR-744-3p: 0.26[--0.28-1.57] versus -0.41[-0.83--0.03], p_adj < 0.001; Log₁₀miR-324-3p: 0.40[-0.09-0.84] versus -0.12[-0.53-0.29], p_adj < 0.001; Log₁₀miR-330-3p: 0.34[0.08-0.93] versus -0.07[-0.65-0.22], p_adj < 0.001), The area under the receiver operating characteristic curve for the combination of these three miRNAs in distinguishing between PR from PE in training and test set was 0.764 (0.679-0.850, sensitivity = 86.2%, specificity = 54.4%, P < 0.001) and 0.768 (0.637-0.898, sensitivity,65.4%, specificity:80.0%, P = 0.001), respectively.

CONCLUSION

A set of circulating microRNAs (miR-744-3p, miR-330-3p, and miR-324-3p) is associated with PR and has clinical utility as a diagnostic marker for distinguishing the plaque phenotype in STEMI patients.

Common diseases alter the physiological age-related blood microRNA profile

Aging is a key risk factor for chronic diseases of the elderly. MicroRNAs regulate post-transcriptional gene silencing through base-pair binding on their target mRNAs. We identified nonlinear changes in age-related microRNAs by analyzing whole blood from 1334 healthy individuals. We observed a larger influence of the age as compared to the sex and provide evidence for a shift to the 5' mature form of miRNAs in healthy aging. The addition of 3059 diseased patients uncovered pan-disease and disease-specific alterations in aging profiles. Disease biomarker sets for all diseases were different between young and old patients. Computational deconvolution of whole-blood miRNAs into blood cell types suggests that cell intrinsic gene expression changes may impart greater significance than cell abundance changes to the whole blood miRNA profile. Altogether, these data provide a foundation for understanding the relationship between healthy aging and disease, and for the development of age-specific disease biomarkers.

Unexpected variations in posttranscriptional gene silencing induced by differentially produced dsRNAs in tobacco cells

In plants, posttranscriptional gene silencing (PTGS) is induced by small RNAs (sRNAs) generated from various dsRNA precursors. To assess the impact of dsRNA origin, we compared downregulation of GFP expression triggered by inverted repeat (IR), antisense (AS) and unterminated sense (UT) transcripts transiently expressed from the estradiol-inducible promoter. The use of homogeneously responding tobacco BY-2 cell lines allowed monitoring the onset of silencing and its reversibility. In this system, IR induced the strongest and fastest silencing accompanied by dense DNA methylation. At low induction, silencing in individual cells was binary (either strong or missing), suggesting that a certain threshold sRNA level had to be exceeded. The AS variant specifically showed a deviated sRNA-strand ratio shifted in favor of antisense orientation. In AS lines and weakly induced IR lines, only the silencer DNA was methylated, but the same target GFP sequence was not, showing that DNA methylation accompanying PTGS was influenced both by the level and origin of sRNAs, and possibly also by the epigenetic state of the locus. UT silencing appeared to be the least effective and resembled classical sense PTGS. The best responding UT lines behaved relatively heterogeneously possibly due to complexly arranged T-DNA insertions. Unlike IR and AS variants that fully restored GFP expression upon removal of the inducer, only partial reactivation was observed in some UT lines. Our results pointed out several not yet described phenomena and differences between the long-known silencer variants that may direct further research and affect selection of proper silencer variants for specific applications.

Next Generation Sequencing and Bioinformatics Analysis of Family Genetic Inheritance

Mendelian and complex genetic trait diseases continue to burden and affect society both socially and economically. The lack of effective tests has hampered diagnosis thus, the affected lack proper prognosis. Mendelian diseases are caused by genetic mutations in a singular gene while complex trait diseases are caused by the accumulation of mutations in either linked or unlinked genomic regions. Significant advances have been made in identifying novel diseases associated mutations especially with the introduction of next generation and third generation sequencing. Regardless, some diseases are still without diagnosis as most tests rely on SNP genotyping panels developed from population based genetic analyses. Analysis of family genetic inheritance using whole genomes, whole exomes or a panel of genes has been shown to be effective in identifying disease-causing mutations. In this review, we discuss next generation and third generation sequencing platforms, bioinformatic tools and genetic resources commonly used to analyze family based genomic data with a focus on identifying inherited or novel disease-causing mutations. Additionally, we also highlight the analytical, ethical and regulatory challenges associated with analyzing personal genomes which constitute the data used for family genetic inheritance.

miRSwitch: detecting microRNA arm shift and switch events

Arm selection, the preferential expression of a 3′ or 5′ mature microRNA (miRNA), is a highly dynamic and tissue-specific process. Time-dependent expression shifts or switches between the arms are also relevant for human diseases. We present miRSwitch, a web server to facilitate the analysis and interpretation of arm selection events. Our species-independent tool evaluates pre-processed small non-coding RNA sequencing (sncRNA-seq) data, i.e. expression matrices or output files from miRNA quantification tools (miRDeep2, miRMaster, sRNAbench). miRSwitch highlights potential changes in the distribution of mature miRNAs from the same precursor. Group comparisons from one or several user-provided annotations (e.g. disease states) are possible. Results can be dynamically adjusted by choosing from a continuous range of highly specific to very sensitive parameters. Users can compare potential arm shifts in the provided data to a human reference map of pre-computed arm shift frequencies. We created this map from 46 tissues and 30 521 samples. As case studies we present novel arm shift information in a Alzheimer’s disease biomarker data set and from a comparison of tissues in Homo sapiens and Mus musculus. In summary, miRSwitch offers a broad range of customized arm switch analyses along with comprehensive visualizations, and is freely available at: https://www.ccb.uni-saarland.de/mirswitch/.

Differences in small noncoding RNAs profile between bull X and Y sperm

The differences in small noncoding RNAs (sncRNAs), including miRNAs, piRNAs, and tRNA-derived fragments (tsRNAs), between X and Y sperm of mammals remain unclear. Here, we employed high-throughput sequencing to systematically compare the sncRNA profiles of X and Y sperm from bulls (n = 3), which may have a wider implication for the whole mammalian class. For the comparison of miRNA profiles, we found that the abundance of bta-miR-652 and bta-miR-378 were significantly higher in X sperm, while nine miRNAs, including bta-miR-204 and bta-miR-3432a, had greater abundance in Y sperm (p < 0.05). qPCR was then used to further validate their abundances. Subsequent functional analysis revealed that their targeted genes in sperm were significantly involved in nucleosome binding and nucleosomal DNA binding. In contrast, their targeted genes in mature oocyte were significantly enriched in 11 catabolic processes, indicating that these differentially abundant miRNAs may trigger a series of catabolic processes for the catabolization of different X and Y sperm components during fertilization. Furthermore, we found that X and Y sperm showed differences in piRNA clusters distributed in the genome as well as piRNA and tsRNA abundance, two tsRNAs (tRNA-Ser-AGA and tRNA-Ser-TGA) had lower abundance in X sperm than Y sperm (p < 0.05). Overall, our work describes the different sncRNA profiles of X and Y sperm in cattle and enhances our understanding of their potential roles in the regulation of sex differences in sperm and early embryonic development.

A novel forensic panel of 186-plex SNPs and 123-plex STR loci based on massively parallel sequencing

The MiSeq® FGX Forensic system and the HID-Ion AmpliSeq Panel were previously developed for massively parallel sequencing (MPS) for forensic casework. Among the three major sequencing platforms, BGISEQ-500^TM, which is based on multiple PCRs, is still lacking in forensics. Here, a novel forensic panel was constructed to detect 186 single-nucleotide polymorphisms (SNPs) and 123 short tandem repeats (STRs) with MPS technology on the BGISEQ-500™ platform. First, the library preparation, sequencing process, and data analysis were performed, focusing on the average depth of coverage and heterozygote balance. We calculated the allelic frequencies and forensic parameters of STR and SNP loci in 73 unrelated Chinese Han individuals. In addition, performance was evaluated with accuracy, uniformity, sensitivity, PCR inhibitor, repeatability and reproducibility, mixtures, degraded samples, case-type samples, and pedigree analyses. The results showed that 100% accurate and concordant genotypes can be obtained, and the loci with an abundance in the interquartile range accounted for 92.90% of the total, suggesting reliable uniformity in this panel. We obtained a locus detection rate that was higher than 98.78% from 78 pg of input DNA, and the optimal amount was 1.25-10 ng. The maximum concentrations of hematin and humic acid were 200 and 100 μM, respectively (the ratios of detected loci were 96.52% and 92.41%), in this panel. As a mixture, compared with those of SNPs, minor-contributor alleles of STRs could be detected at higher levels. For the degraded sample, the ratio of detected loci was 98.41%, and most profiles from case-type samples were not significantly different in abundance in our studies. As a whole, this panel showed high-performance, reliable, robust, repeatable, and reproducible results, which are sufficient for paternity testing, individual identification, and use for potentially degraded samples in forensic science.

Hypoxic gene expression in chronic hepatitis B virus infected patients is not observed in state-of-the-art in vitro and mouse infection models

Hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma (HCC) worldwide. The prolyl hydroxylase domain (PHD)-hypoxia inducible factor (HIF) pathway is a key mammalian oxygen sensing pathway and is frequently perturbed by pathological states including infection and inflammation. We discovered a significant upregulation of hypoxia regulated gene transcripts in patients with chronic hepatitis B (CHB) in the absence of liver cirrhosis. We used state-of-the-art in vitro and in vivo HBV infection models to evaluate a role for HBV infection and the viral regulatory protein HBx to drive HIF-signalling. HBx had no significant impact on HIF expression or associated transcriptional activity under normoxic or hypoxic conditions. Furthermore, we found no evidence of hypoxia gene expression in HBV de novo infection, HBV infected human liver chimeric mice or transgenic mice with integrated HBV genome. Collectively, our data show clear evidence of hypoxia gene induction in CHB that is not recapitulated in existing models for acute HBV infection, suggesting a role for inflammatory mediators in promoting hypoxia gene expression.

Metabolome and transcriptome analyses reveal chlorophyll and anthocyanin metabolism pathway associated with cucumber fruit skin color

BACKGROUND

Fruit skin color play important role in commercial value of cucumber, which is mainly determined by the content and composition of chlorophyll and anthocyanins. Therefore, understanding the related genes and metabolomics involved in composition of fruit skin color is essential for cucumber quality and commodity value.

RESULTS

The results showed that chlorophyll a, chlorophyll b and carotenoid content in fruit skin were higher in Lv (dark green skin) than Bai (light green skin) on fruit skin. Cytological observation showed more chloroplast existed in fruit skin cells of Lv. A total of 162 significantly different metabolites were found between the fruit skin of the two genotypes by metabolome analysis, including 40 flavones, 9 flavanones, 8 flavonols, 6 anthocyanins, and other compounds. Crucial anthocyanins and flavonols for fruit skin color, were detected significantly decreased in fruit skin of Bai compared with Lv. By RNA-seq assay, 4516 differentially expressed genes (DEGs) were identified between two cultivars. Further analyses suggested that low expression level of chlorophyll biosynthetic genes, such as chlM, por and NOL caused less chlorophylls or chloroplast in fruit skin of Bai. Meanwhile, a predicted regulatory network of anthocyanin biosynthesis was established to illustrate involving many DEGs, especially 4CL, CHS and UFGT.

CONCLUSIONS

This study uncovered significant differences between two cucumber genotypes with different fruit color using metabolome and RNA-seq analysis. We lay a foundation to understand molecular regulation mechanism on formation of cucumber skin color, by exploring valuable genes, which is helpful for cucumber breeding and improvement on fruit skin color.

Mapping a mammalian adult adrenal gland hierarchy across species by microwell-seq

Recently, single-cell RNA-seq technologies have been rapidly updated, leading to a revolution in biology. We previously developed Microwell-seq, a cost-effective and high-throughput single cell RNA sequencing(scRNA-seq) method with a very simple device. Most cDNA libraries are sequenced using an expensive Illumina platform. Here, we present the first report showing combined Microwell-seq and BGI MGISEQ2000, a less expensive sequencing platform, to profile the whole transcriptome of 11,883 individual mouse adult adrenal gland cells and identify 18 transcriptionally distinct clusters. Moreover, we performed a single-cell comparative analysis of human and mouse adult adrenal glands to reveal the conserved genetic networks in these mammalian systems. These results provide new insights into the sophisticated adrenal gland hierarchy and provide a benchmark, low-cost strategy for high-throughput single-cell RNA study.

Transcriptomics reveal high regulatory diversity of drought tolerance strategies in a biennial oil crop

Spring droughts are expected to become more frequent in Central Europe as a result of climate change. Their coincidence with flowering of biennial crops like winter oilseed rape (Brassica napus) can cause major impact for yield development. However, no data is available on the diversity of genetic regulation of drought tolerance during this stage under realistic conditions. Here, we assessed the phenotypic plasticity of drought response for eight diverse B. napus accessions under field-like conditions and linked their stress response to gene and miRNA expression during early and late stress. We observed highly diverse responses, both on the phenotypic and on the gene expression level. Our data suggest that drought tolerant accessions have more effective molecular protection mechanisms like ROS scavenging, source/sink ratio and regulation of developmental timing, compared to otherwise phenotypically similar accessions. Bna.MAP3K13.C05 expression was found to be protective independently of the tolerance mechanism, indicating cross-talk to nitrogen signaling. Moreover, we identified putative miRNA genes in the B. napus genome which respond to stress and may also be involved in protective mechanisms, representing possible breeding targets.

A FAK/HDAC5 signaling axis controls osteocyte mechanotransduction

Osteocytes, cells ensconced within mineralized bone matrix, are the primary skeletal mechanosensors. Osteocytes sense mechanical cues by changes in fluid flow shear stress (FFSS) across their dendritic projections. Loading-induced reductions of osteocytic Sclerostin (encoded by Sost) expression stimulates new bone formation. However, the molecular steps linking mechanotransduction and Sost suppression remain unknown. Here, we report that class IIa histone deacetylases (HDAC4 and HDAC5) are required for loading-induced Sost suppression and bone formation. FFSS signaling drives class IIa HDAC nuclear translocation through a signaling pathway involving direct HDAC5 tyrosine 642 phosphorylation by focal adhesion kinase (FAK), a HDAC5 post-translational modification that controls its subcellular localization. Osteocyte cell adhesion supports FAK tyrosine phosphorylation, and FFSS triggers FAK dephosphorylation. Pharmacologic FAK catalytic inhibition reduces Sost mRNA expression in vitro and in vivo. These studies demonstrate a role for HDAC5 as a transducer of matrix-derived cues to regulate cell type-specific gene expression.

DNB-based on-chip motif finding: A high-throughput method to profile different types of protein-DNA interactions

Here, we report a sensitive DocMF system that uses next-generation sequencing chips to profile protein-DNA interactions. Using DocMF, we successfully identified a variety of endonuclease recognition sites and the protospacer adjacent motif (PAM) sequences of different CRISPR systems. DocMF can simultaneously screen both 5' and 3' PAMs with high coverage. For SpCas9, we found noncanonical 5'-NAG-3' (~5%) and 5'-NGA-3' (~1.6%), in addition to its common PAMs, 5'-NGG-3' (~89.9%). More relaxed PAM sequences of two uncharacterized Cas endonucleases, VeCas9 and BvCas12a, were extensively characterized using DocMF. Moreover, we observed that dCas9, a DNA binding protein lacking endonuclease activity, preferably bound to the previously reported 5'-NGG-3' sequence. In summary, our studies demonstrate that DocMF is the first tool with the capacity to exhaustively assay both the binding and the cutting properties of different DNA binding proteins.

Understanding the heat resistance of cucumber through leaf transcriptomics

Heat stress is a major environmental factor limiting plant productivity and quality in agriculture. Cucumber, one of the most important vegetables among cucurbitaceae, prefers to grow in a warm environment. Until now the molecular knowledge of heat stress in cucumber remained unclear. In this study, we performed transcriptome analysis using two diverse genetic cucumber cultivars, L-9 and A-16 grown under normal and heat stress. L-9 displayed heat-tolerance phenotype with higher superoxide dismutase enzyme (SOD) enzyme activity and lower malondialdehyde (MDA) content than A-16 under heat stress. RNA-sequencing revealed that a total of 963 and 2778 genes are differentially expressed between L-9 and A-16 under normal and heat stress respectively. In addition, we found that differentially expressed genes (DEGs) associated with plant hormones signally pathway, transcription factors, and secondary metabolites showed significantly change in expression level after heat stress, which were confirmed by quantitative real-time PCR assay. Our results not only explored several crucial genes involved in cucumber heat resistance, but also provide a new insight into studying heat stress.

Knockdown of LAP2α inhibits osteogenic differentiation of human adipose-derived stem cells by activating NF-κB

BACKGROUND

Lamina-associated polypeptide 2α (LAP2α) is a nucleoplasmic protein that has been involved in the regulation of the cell cycle, gene transcription, and adult stem cell function. LAP2α down-regulation is linked to age-related osteoporosis and bone deformities; however, the underlying mechanisms remain obscure. The present study aimed to elucidate the function of LAP2α in the osteogenic differentiation of human adipose-derived stem cells (hASCs), which are attractive sources for bone tissue engineering.

METHODS

The expression of LAP2α during the osteogenic differentiation of hASCs was detected firstly. A loss of function investigation was then carried out to characterize the function of LAP2α in osteogenic differentiation of hASCs both in vitro and in vivo. Moreover, RNA-sequences, western blotting, and confocal analyses were performed to clarify the molecular mechanism of LAP2α-regulated osteogenesis.

RESULTS

We found that LAP2α expression was upregulated upon osteogenic induction. Both in vitro and in vivo experiments indicated that LAP2α knockdown resulted in impaired osteogenic differentiation of hASCs. Mechanistically, we revealed that LAP2α deficiency activated nuclear factor kappa B (NF-κB) signaling by controlling the cytoplasmic-nuclear translocation of p65.

CONCLUSIONS

Collectively, our findings revealed that LAP2α functions as an essential regulator for osteogenesis of hASCs by modulating NF-κB signaling, thus providing novel insights for mesenchymal stem cell-mediated bone tissue engineering.