Identifying DNA methylation biomarkers using nanopore sequencing
Carcinogenesis is associated with changes in DNA methylation patterns, especially in CpGs islands, which are region in the human genome with an increased amount of CpG dinucleotides. Using methylation-specific PCR based on bisulfite treated DNA, these methylated cytosine loci (cytosines beeing methylated into 5-methyl cytosines, an epigenetic change occurring in the early stages of cancer already, can be used for clinical screening tests. In cooperation with oncgnostics GmbH, are using Nanopore sequencing to identify potential methylation-specific genomic cancer biomarker regions in the human genome, which can be used as targets for the develoment of methylation-specific screening tests. In the scope of this project, the tool diffoNT has been developed, which predicts genomic regions, which are suitable for methylation-specific PCR.
People involved: Daria Meyer
Collaborations: oncgnostics GmbH
Related publications:
Maximizing the potential of genomic and transcriptomic studies by nanopore sequencing Journal Article
In: bioRxiv, 2023.
Quantifying Liver Perfusion
The liver is crucial for whole-body metabolic homeostasis, handling lipid, carbohydrate, and detoxification metabolism, which are coordinated by its spatial organization and perfusion. With the rise in liver tumors and metastases, advanced surgical procedures are required, which allow for removal of up to 70% of liver volume, but leads to an increased risk of postoperative liver failure.
In cooperation with both clinicians and modellers, our aim is to understand and describe transcriptomic changes after these extended partial hepatectomy surgeries.
We analyzed data from rats, which underwent a portal vein ligation, a procedure performed before partial hepatectomy during which diseased liver lobes are ligated with the expectation that non-ligated liver-lobes increase in size. We sequenced tissue extracted at different time points (2d, 5d) from different parts (right median liver lobe, left median liver lobe) of the liver and compared the gene expression betweeen the conditions and the resulting enriched pathways.
People involved: Daria Meyer, Emanuel Barth, Manja Marz
Collaborations: Bruno Christ, Uta Dahmen, Michael Tautenhahn, Matthias König
Grants: DFG FOR 5151 QuaLiPerF / MA5082/15-1
Related publications:
Data report on gene expression after hepatic portal vein ligation (PVL) in rats Journal Article
In: Front Genet, vol. 15, pp. 1421955, 2024.
In: Front Physiol, vol. 12, pp. 733868, 2021.
VirJenDB: the virus database based in Jena
The NFDI4Microbiota consortium is a DFG-funded project involving 10 German institutions, constituting research groups with a focus on microbiology and research data management. The NFDI4Microbiota aims to be the central hub in Germany for supporting the microbiology community with FAIR and Open infrastructure, access to data, analysis services, data/metadata standards, and training. VirJenDB is a service and Use Case of the NFDI4Microbiota, funded by DFG grant number NFDI 28/1 (DFG project number 460129525) since 2021 at the Friedrich Schiller University in Jena, Germany. The website has been live since 10 February 2024 and is currently available in the beta version v0.1.
The VirJenDB team aims to provide a data analysis platform for researchers to find, access, curate, download and analyze sequences and (meta)data from all viruses. Virus sequences and metadata are ingested from repositories (INSDC) and secondary databases and knowledge resources (BV-BRC, NCBI Virus, ViralZone, ICTV), curated, harmonized and integrated into a metadata model. The website provides search, browse, download and summary functionality for the VJDB dataset. The VJDB is developed on the de.NBI cloud as an OpenStack project and uses the NFDI service Aruna Object Storage for sequence storage as well as the NFDI4Microbiota ClowM management system for workflows. Upcoming plans include the integration and visualization of sequence alignments and metagenomic sequences.
People involved: Noriko Cassman
Grants: NFDI4Microbiota
Related publications:
Navigating the Landscape: A Comprehensive Review of Current Virus Databases Journal Article
In: Viruses, vol. 15, iss. 9, no. 1834, 2023, ISBN: 1999-4915.
Signal Segmentation in Oxford Nanopore Technologies Data Using HMM Models
The goal of this project is to accurately align measured Oxford Nanopore Technologies (ONT) signals to nucleotide sequences by leveraging Hidden Markov Models (HMMs). The ONT sequencing platform generates raw signal data that needs to be segmented and mapped to the corresponding nucleotide sequences for further biological interpretation.
To achieve this, I utilize the Baum-Welch Algorithm, also known as the Forward-Backward Algorithm, which is a standard technique for training HMMs. This algorithm iteratively adjusts the model parameters to maximize the likelihood of the observed sequence data. By aligning the raw ONT signals to the nucleotide sequences, this project aims to improve the accuracy and reliability of ONT-based sequencing analysis.
The successful implementation of this approach will provide a robust framework for decoding ONT signal data, paving the way for more precise genomic studies and applications.
People involved: Jannes Spangenberg, Manja Marz
Past people involved: Christian Hoener zu Siederdissen
Detection of RNA Modifications in Oxford Nanopore Technologies Data Using Neural Networks
This project focuses on the detection of RNA modifications within Oxford Nanopore Technologies (ONT) signal data using advanced neural network models. RNA modifications play a crucial role in various biological processes, and their detection is essential for understanding gene expression regulation and other cellular mechanisms.
ONT sequencing generates complex signal data that contains information about both the nucleotide sequence and potential modifications. The challenge lies in accurately identifying these modifications amidst the noise and variability inherent in the raw signal data. In this project, I employ deep learning techniques, specifically neural networks, to analyze and classify ONT signals to detect RNA modifications.
The neural network models are trained on labeled datasets, where modified and unmodified RNA sequences are known. By learning the subtle differences in the signal patterns, the models aim to distinguish between modified and unmodified regions with high accuracy. This project has the potential to significantly enhance the understanding of RNA biology by providing a powerful tool for the detection of RNA modifications in sequencing data.
People involved: Jannes Spangenberg, Manja Marz
Past people involved: Christian Hoener zu Siederdissen
Related publications:
Maximizing the potential of genomic and transcriptomic studies by nanopore sequencing Journal Article
In: bioRxiv, 2023.
Magnipore: Prediction of differential single nucleotide changes in the Oxford Nanopore Technologies sequencing signal of SARS-CoV-2 samples Journal Article
In: bioRxiv, 2023.
Molecular genetic, metagenomic and bioinformatic studies on the endometrium and placenta
As a member of the Collaborative Research Center CEPRE (Center for Early Pregnancy and Reproductive Health), our subproject also aims to improve the understanding of possible misregulation of non-coding genes and metagenomics in infertile women. We will investigate the molecular genetic differences between infertile and fertile women before pregnancy, in the first trimester and during pregnancy. The study will mainly be conducted bioinformatically by transcriptomic analyses of the endometrium, decidua and placenta. In addition to protein-coding transcripts, the main focus will be on non-coding RNAs. In addition, we will investigate the metagenomic composition of viruses and bacteria in the uterus and their differences in infertile and fertile women.
People involved: Stephan Kastner, Manja Marz
Collaborations: Udo Markert, Ekkehard Schleußner, Diana Maria Morales Prieto, Regine Heller
Grants: BMBF – 01GR2305B CEPRE – Center for Early Pregnancy and Reproductive Health
The virome of the lung
Even today, it still happens that patients die in hospital from pneumonia or other respiratory symptoms without the exact cause being known. One possible cause could be infection with an unknown virus. To find out, our first goal is to develop a method to identify rare viruses in the superimposed human background using metagenomic approaches. The method will then be validated in microbe-positive patients. The next step will be to analyse BAL (bronchoalveolar lavage) samples from patients with respiratory symptoms but without positive clinical microbial findings to identify a possible viral cause of the disease. A correlation between the symptoms and the individual genes of the virus is expected to determine whether an identified virus is truly pathogenic.
People involved: Stephan Kastner, Noriko Cassman, Manja Marz
Past people involved: Johanna Luise Gorki
Collaborations: Susanne Lang
Grants: Digitalisierung der Lebenswissenschaften: Wege in die Zukunft
FRESCO-Phage: Longterm transfer of FRozen, Encapsulated multidonor Stool bacteriophage filtrates for active ulcerative COlitis
Inflammatory bowel disease (IBD) is a global disease of the 21st century. In the US, it is currently estimated that about 1-1.3 million people suffer from IBD. The exact etiology of IBD is unknown, however, one of the debated reasons is dysbiosis of the intestinal microbiota. Ulcerative colitis (UC) and Crohn’s disease are two main forms of IBD. The diversity of microbiota in gut of IBD patients is reduced; and multidonor intensive faecal microbiota transplantation during active UC is maintained. Kill-the-winner dynamics suggest that bacteriophages regulate the microbiome, making them an interesting target in UC. FRESCO, a BMBF research program longitudinally tracking multidonor stool transplantations in hundreds of UC patients (Prof. Stallmach, 1.6 MEUR) includes a conservative treatment for active mild to moderate UC by a) sterile faecal microbiota filtrate transplantation (SFMFT), b) classical faecal microbiota transplantation (FMT); and c) placebo in patients with active UC. As the 0.22 um filters used for SFMFT allow bacteriophages to pass, this experimental setup allows us to investigate the role of bacteriophages on the composition of the gut microbiome, and their role in UC.
In FRESCO-Phage we want to understand the role of viruses as potential regulators of the bacterial community and therefore the microbiome. For this we aim to analyze the bacterial community and separately the viruses from stool of the donor and transplant only viruses into the patients with active UC. We will analyse the microbiome (bacteria and viruses) before and after transplantation.
People involved: Stephan Kastner, Noriko Cassman, Tom Eulenfeld, Manja Marz
Past people involved: Johanna Luise Gorki
Collaborations: Andreas Stallmach
Grants: DFG EXC2051 – Balance of the Microverse
Alternative splicing and isoforms
Alternative splicing is an important process of gene regulation whereby a single gene can produce multiple mRNA isoforms with different functions. The formation of different isoforms consequently leads to protein diversity and increased functional complexity. Understanding the changes in alternative splicing patterns in response to different conditions can provide valuable insights into disease mechanisms and the identification of potential therapeutic targets. Our research investigates the role of alternative splicing and the use of different isoforms in health and disease, looking at RNA-Seq data from humans, rats, mice and fish. We want to identify genes that undergo differential splicing and use differential isoform under specific conditions, like viral infections or ageing.
People involved: Maria Schreiber
A comprehensive toxin-antitoxin atlas
The threat posed by antibiotic-resistant bacteria is considerable. However, the existence of toxin-antitoxin (TA) systems in these microbes may facilitate the development of novel treatment options. TA systems function as a kind of self-destruct mechanism with antidotes. Further research is required to ascertain their potential as a means of combating or controlling antibiotic-resistant bacteria. The next step is to identify the presence of these systems in all bacteria and archaea at different levels (primary, secondary, tertiary) and to gain a deeper understanding of their function. This will entail analysing their interactions and investigating their evolutionary development. Finally, the aim is to demonstrate in the laboratory that the systems identified are indeed functional.
People involved: Maria Schreiber, Emanuel Barth
Bioinformatics support for researchers of the FSU and associated research institutes
The Bioinformatics Core Facility Jena (BiC) provides free support for researchers of the Friedrich Schiller University and associated research institutes in Jena at all stages of bioinformatics analysis. The support we offer ranges from consultations, basic bioinformatics services, and scientific workshops to full research collaborations. For our basic bioinformatics services, we have established modern, standardized workflows for numerous tasks in the field of high-throughput analysis and related research areas, starting with data quality control up to the final visualization of the results. For special applications, where our standardized methods reach their limits or a deeper interpretation of the results is desired, we offer individually adapted solutions in the form of full research collaboration. In the end, our aim is to contribute to the interdisciplinarity and development of life science research projects in Jena. Through our still-growing network of scientific partners, we have the opportunity to work on a huge variety of different topics.
People involved: Emanuel Barth, Muriel Ritsch, Sebastian Krautwurst, Daria Meyer
Viruses in groundwater
The principle aim of the CRC AquaDiva is to increase our understanding of the links between surface and subsurface, especially how organisms inhabiting the subsurface critical zone reflect and influence their physical, ecological and geochemical environment. In project A06, we will determine the diversity of previously known viruses in groundwater by high-throughput sequencing of viral genomes. A challenge in virology is the identification of previously undetected viruses, which we will tackle with our new approach to virus assembly. We complement this approach with a comparison of different protocols for the metagenomic identification of the groundwater virom. Finally, we will determine the largely unknown virus half-lives of various viruses in groundwater in order to gain insights into their ability to reproduce even in the long-term absence of the host.
People involved: Christian Höner zu Siederdissen, Stephan Kastner, Franziska Hufsky, Janina Rahlff, Noriko Cassman, Manja Marz
Past people involved: Akash Srivastava, Sebastian Krautwurst, Muriel Ritsch, Milena Žarković
Collaborations: Kirsten Küsel, Antonis Chatzinotas, René Kallies, Christian Jogler
Grants: CRC 1076 — AquaDiva: A6: Viral Diversity, Viral de novo Assembly, and Viral Decay in Groundwater
Related publications:
Carbon fixation rates in groundwater similar to those in oligotrophic marine systems Journal Article
In: Nat Geosci, vol. 15, pp. 561–567, 2022.
The economical lifestyle of CPR bacteria in groundwater allows little preference for environmental drivers Journal Article
In: Environ Microbiome, vol. 16, no. 1, pp. 24, 2021.
Inclusion of Oxford Nanopore long reads improves all microbial and viral metagenome-assembled genomes from a complex aquifer system Journal Article
In: Environ Microbiol, vol. 22, no. 9, pp. 4000-4013, 2020.
Evaluation of Sequencing Library Preparation Protocols for Viral Metagenomic Analysis from Pristine Aquifer Groundwaters. Journal Article
In: Viruses, vol. 11, no. 6, pp. 484, 2019.
Biogeochemical regimes in shallow aquifers reflect the metabolic coupling of elements of nitrogen, sulfur and carbon. Journal Article
In: Appl Environ Microbiol, vol. 85, no. 5, pp. e02346-18, 2019.
Candidate Brocadiales dominates C, N and S cycling in anoxic groundwater of a pristine limestone-fracture aquifer Journal Article
In: J Proteomics, vol. 152, pp. 153–160, 2016.
Ecology and species barriers in emerging viral diseases
Emerging viruses existing in animal reservoirs may cause epidemic or epizootic diseases if transmitted to humans or livestock. While we understand the pathogenicity and epidemiology of prototypic emerging viral diseases, we know little about the mechanisms driving virus emergence from animal reservoirs. To move ahead, we need to generalize our view on emerging viruses, taking into consideration the ecology of viruses in their natural reservoirs. We hypothesize that small mammals, mainly bats, and rodents, constitute the most relevant virus reservoirs due to their large group sizes, population density, mixing, and turnover, as well as their exposure to arthropod vectors.
People involved: Marie Lataretu, Gabriel Lencioni Lovate, Daria Meyer
Past people involved: Martin Hölzer, Nelly Fernanda Mostajo Berrospi
Collaborations: Christian Drosten, Friedemann Weber, Stephan Becker, Martin Beer, Georg Kochs
Grants: DFG SPP 1596: Ecology and Species Barriers in Emerging Viral Diseases
Related publications:
A comprehensive annotation and differential expression analysis of short and long non-coding RNAs in 16 bat genomes Journal Article
In: NAR Genomics Bioinf, vol. 2, no. 1, pp. lqz006, 2019.
Differential transcriptional responses to Ebola and Marburg virus infection in bat and human cells Journal Article
In: Sci Rep, vol. 6, pp. 34589, 2016.
Limiting viral outbreaks with Machine Learning
Zoonosis, the natural transmission of infections from animal to human, is a far-reaching global problem, occurring more often due to globalization. In case of a virus outbreak, it is helpful to know which host organism was the original carrier of the virus, so people can be separated from these hosts. The sooner this happens, the greater the chances of limiting an outbreak.
As a fast method of predicting the original host, we are working on the ability to predict the host of a virus based on the viral genome sequence. Due to the lack of knowledge about virus adaptation, it is difficult to find practical features for machine learning methods. With this in mind, we apply deep learning methods because they do not require predefined features and are one of today’s most powerful machine learning methods.
People involved: Florian Mock
Past people involved: Adrian Viehweger
Related publications:
VIDHOP, viral host prediction with Deep Learning Journal Article
In: Bioinformatics, vol. 37, no. 3, pp. 318–325, 2020.
Viruses in host genomes
Overall, little is known about the composition of the human genome. For example, it is assumed that 50% consist of repetitive sequences, whose function is still undescribed. These include SINEs or LINEs, which are thought to be of viral origin. Another component of the genome is the rarely described Endogenous Viral Elements (EVEs). These can be divided into rarely analyzed retrotransposons and other previously undescribed viral elements. Normally, retroviruses infect somatic cells and integrate their genetic material into the host genome. Infrequently, retroviruses are integrated into germline cells, in which case the viral genome can be passed on to offspring by sexual transmission. This process of integration is called endogenization. It was assumed that only retroviral viruses could integrate into the host genome (since for these viruses, integration was a necessary step in their life cycle). Surprisingly, several non-retroviral elements have already been found in different genomes, but these are confirmed individual occurrences, and there is no detailed catalog of EVEs. Little is known about the integration of non-retroviral EVEs. It has been frequently reported that the human genome harbors 8% viral elements. However, this number refers only to retroviruses and is almost 20 years old. At that time, much less was known about viruses and their replication mechanisms. Sequencing techniques and bioinformatic programs have also evolved enormously since then. It is therefore very surprising that, despite the description of individual non-retroviral elements in the human genome, there has been no fundamental systematic revalidation of the viral elements in the human genome that has occurred.
In their project, we address three fundamental questions: (1) How many viral elements are there in the human genome? (2) Are they functional? (3) Are the viral fragments accumulated over a human lifetime, or are they essentially inherited?
People involved: Muriel Ritsch
RNA structures and functions in viruses
Non-coding RNAs (ncRNA) are known regulatory elements in organisms from all kingdoms. The secondary structure of RNA is often linked to its function. When looking at a viral genome (especially an RNA genome) it only makes sense that viruses make strong use of ncRNAs to bypass the host’s immune response, regulate their own genes, or stop the gene expression of the host genes. We are concerned with the analysis of conserved RNA structures in well-described virus families and the de novo prediction of potentially functional structural elements in less known families. We use combinations of machine learning, clustering, and homology-based methods. The identification of functional structural elements could help to develop new antiviral therapies in the future, as important replication mechanisms of the virus can be disturbed.
People involved: Kevin Lamkiewicz, Gabriel Lovate, Sandra Triebel
Related publications:
Comprehensive survey of conserved RNA secondary structures in full-genome alignment of Hepatitis C virus Journal Article
In: Scientific Reports, vol. 14, iss. 1, 2024.
RNA-Protein Interaction Prediction without High-Throughput Data: An Overview and Benchmark of in silico Tools Journal Article
In: bioRxiv, 2024.
HIV-1 lethality and loss of Env protein expression induced by single synonymous substitutions in the virus genome intronic splicing silencer Journal Article
In: J Virol, vol. 94, no. 21, 2020.
Structural and functional conservation of cis-acting RNA elements in coronavirus 5'-terminal genome regions Journal Article
In: Virology, vol. 517, pp. 44–55, 2017.
Deciphering the RNA genome packaging code of influenza A viruses
Currently, bioinformatical tools are not specifically designed for viruses. However, viruses bring unique features, which require specific bioinformatical tools to trace virus-host interaction. For example, the number of sequences in quasispecies is massively high due to their high mutation rate, but only a few interact again with the host cells. Some viruses, such as IAV or as used by AG, are segmented RNA viruses, which urgently require tools with specific features: RNA viruses should include standardized secondary structure predictions, leading to RNA-RNA interaction prediction necessary for the packaging of segmented RNA viruses.
The aims of this project are to develop a bioinformatical tool to predict RNA-RNA interactions as packaging signal for segmented viruses, such as IAV, to develop a virus-specific full genome multiple sequence alignment algorithm to track the quasispecies; and to establish RNA-RNA interaction sets and more importantly non-interaction sets.
People involved: Gabriel Lovate, Daniel Desiro, Kevin Lamkiewicz
Collaborators: Roland Marquet, Andreas Henke
Grants: HORIZON 2020 MSCA ITN — VIROINF: Understanding (harmful) virus-host interactions by linking virology and bioinformatics.
Sequential disruption of SPLASH-identified vRNA–vRNA interactions challenges their role in influenza A virus genome packaging Journal Article
In: Nucleic Acids Research, 2023, ISBN: 0305-1048.
The complexity of packaging mechanisms in segmented RNA viruses PhD Thesis
2022.
SilentMutations (SIM): a tool for analyzing long-range RNA-RNA interactions in viral genomes and structured RNAs Journal Article
In: Virus Res, vol. 260, pp. 135-141, 2018.
Virus Database, interface, and quality control
The NFDI4Microbiota consortium comprises 10 German partner institutions (including FSU Jena) and aims to build a centralized infrastructure with services for microbiome research. Viruses are a fundamental part of the microbiome and their investigation requires specialized tools and resources. Here at FSU Jena, we are building a virus genome sequence database encompassing all viruses, which will be used by virologists, viral ecologists, and others worldwide in accordance with the FAIR principles. We will do this by consulting the global network of virus experts, integrating expert knowledge and existing database structures, and incorporating international metadata standards. We plan to curate and provide an interface to access the virus genome sequences from public repositories e.g. the European Nucleotide Archive (ENA), the Sequence Read Archive (SRA), and GenBank/NCBI viruses. Further, we will offer visualization, analysis, and sharing of user-uploaded virus data, ensuring data protection for embargoed and private datasets.
People involved: Shahram Saghaei, Noriko Cassman, Sandra Triebel
Collaborations: NFDI4Microbiota
High-quality full-genome alignments of viruses
Multiple sequence alignments (MSAs) reveal homologous regions of input sequences and thus serve as a starting point for phylogenetic analyses at the molecular level. High quality MSAs can be used to assess the conservation of primary sequence and even secondary structure. In particular, alignments of viral sequences are challenging due to their high mutation rate. Our goal is to generate high-quality full-genome alignments of virus families and clades by first selecting representative genomes of a dataset via clustering. The alignment is generated by incorporating information at the amino acid, nucleotide and RNA secondary structure level using current homology-based methods and developing new methods to cope with the diversity of viral sequences. High-quality alignments of viruses can provide insights into differences and similarities at the DNA/RNA level within a virus family. At the same time, providing such information as results of codon corrections (RNA sequence to protein) or compensatory mutations (RNA sequence to RNA secondary structure) is a major challenge.
People involved: Sandra Triebel, Tom Eulenfeld, Kevin Lamkiewicz, Noriko Cassman
Related publications:
Rfam 15: RNA families database in 2025 Journal Article
In: bioRxiv, 2024.
Comprehensive survey of conserved RNA secondary structures in full-genome alignment of Hepatitis C virus Journal Article
In: Scientific Reports, vol. 14, iss. 1, 2024.
RNA-Protein interactions
RNA-protein interactions (RPIs) are ubiquitous throughout the kingdoms of life and play essential roles between and within organisms. The goal of this project is to develop computational models and algorithms to better understand the mechanisms of these interactions.
Inspired by compensatory mutations in RNAs, we calculate co-alignments between homologous RNAs and proteins of a potential RPI complex. Combined with structure information of both, RNA and protein, we aim to correlate mutations with potential interaction sites. From there, we will deduce rules and restrictions to predict other RPI complexes. Because viral RPIs are generally less well investigated, they are of particular interest.
Currently, we reviewed and evaluated available RPI prediction tools with selected RPI examples. Since the landscape of computational methods still needs improvement, we hope to contribute to developing an RPI prediction tool that will enable the reliable detection of promising novel RPIs in various organisms.
People involved: Sarah Krautwurst, Kevin Lamkiewicz
Related publications:
RNA-Protein Interaction Prediction without High-Throughput Data: An Overview and Benchmark of in silico Tools Journal Article
In: bioRxiv, 2024.
Improvement of ONT basecaller
People involved: Christian Höner zu Siederdissen, Jannes Spangenberg, Sebastian Krautwurst
Detecting RNA modifications with nanopore sequencing
RNA modifications such as the highly abundant N6-methyladenosine (m6A) are known as an important aspect of RNA biology. For example, m6A modification has been shown to be involved in the regulation of mRNA processing, but also RNA virus replication and translation. Second-generation sequencing methods for m6A detection are limited to position-only inference on known reference sequences. Nanopore direct RNA sequencing enables the assessment of modification status of individual reads at single-nucleotide resolution, but current detection models are still limited to position-only inference. We aim to use deep neural networks for de-novo modification detection on nanopore data that achieves high accuracy at single read, single-nucleotide resolution.
People involved: Christian Höner zu Siederdissen, Sebastian Krautwurst, Jannes Spangenberg
Related publications:
Maximizing the potential of genomic and transcriptomic studies by nanopore sequencing Journal Article
In: bioRxiv, 2023.
Magnipore: Prediction of differential single nucleotide changes in the Oxford Nanopore Technologies sequencing signal of SARS-CoV-2 samples Journal Article
In: bioRxiv, 2023.
Direct RNA Sequencing for Complete Viral Genomes Book Section
In: Frishman, Dmitrij; Marz, Manja (Ed.): Virus Bioinformatics, CRC Press, 2021.
In: Genome Res, vol. 29, pp. 1545-1554, 2019.
The correlation of genome size and DNA methylation rate in metazoans Journal Article
In: Theory Biosci, vol. 132, pp. 47–60, 2012.
Identifying DNA methylation biomarkers using nanopore sequencing
Carcinogenesis is associated with DNA methylation changes. Especially the methylation of 5-methylcytosine (5mC) in the context of regions with numerous 5’-cytosine-phosphate-guanine-3’ (CpG) occurrences, so-called CpG islands, plays a role here. These DNA methylation changes occur already at an early stage of cancer. Additionally, it is relatively simple to develop molecular biological tests once the regions of differential methylation are known. Therefore it is convincing to use DNA methylations for cancer screening. Nanopore sequencing makes it possible to identify DNA base modifications (e.g., 5mC) at nucleotide resolution. We aim to develop a workflow to identify DNA methylation cancer biomarkers for cancer subtypes that are not well studied yet.
People involved: Daria Meyer, Milena Žarković
Collaborations: oncgnostics GmbH
Cell-free RNA sequencing
Cell-free RNA is present in the blood of every human being as a result of vesicular secretion from the cells of the human body. Sequencing cell-free RNA has been very promising for the diagnosis of several diseases ranging from cancer to cardiovascular diseases. In contrast to protein-based biomarkers, a huge advantage of RNA is that it can be amplified. In recent years technological developments enabled the amplification and sequencing of tiny amounts of RNA even from single cells. Another advantage of RNA over DNA (which could also be amplified) is that it is continuously shed from cells. In contrast, DNA exits cells only when the cell is dying. Hence, cell-free RNA holds the promise of continuous probing of transcriptional changes in the cells of the human body. We aim to apply methods from the field of single-cell RNA sequencing to sequence cell-free RNA in different medically relevant contexts. This approach enables the sequencing of minute amounts of RNA and our expertise in sequencing very small amounts of RNA from cells or even phase-separated condensates will facilitate the detection of even the smallest amounts of RNA from the blood or other body fluids.
People involved: Damian Wollny, Julia Micheel, Aram Safrastyan, Franziska Aron
Antibiotic resistance in the Ganges river valley
Antibiotics increasingly fail to treat a growing number of medical conditions due to antimicrobial resistance. This trend is especially acute in developing countries such as India, where broad resistances are known to have emerged. It is known that densely populated cities can drive the emergence and spread of antimicrobial resistance through for example industrial production sites, wastewater management practices, and other cultural characteristics. Proximity to waterways or associated water collections seems especially relevant.
To identify controllable drivers of resistance emergence and spread we investigate two cities on the river Ganges in India – Allahabad and Kanpur. We also investigate the effect of human interference by analyzing samples before and after Kumbh Mela, which is by far the largest religious gathering in Prayagraj. This will allow us to discern naturally occurring resistance from resistance created by humans.
People involved: Akash Srivastava, Sebastian Krautwurst
Collaborations: Ziauddin Ahammad Shaikh, Adrian Viehweger
Grants: BMBF – DBT Cooperative Science Program: Development of metagenomics assisted surveillance tools for tracking antibiotic resistance in river bodies — A study in the Ganges river valley (NANOLOG)
Epigenetic profiling of aging mouse brain at base resolution
Recent studies have proven that epigenetics, especially 5-methylcytosine (5mC), plays a pivotal role in aging. Along these lines, previous studies have reported diverse epigenetic profiles among different cell types like neurons and oligodendrocytes of the same individual. Besides methylation, DNA undergoes various other types of epigenetic modification. It remains to be investigated if these modifications changes upon aging and can thus also serve as an alternative reliable molecular marker of the epigenetic age of an individual. Thus, it is essential to identify variations in other epigenetic modifications of DNA in specific cell types from the same individual. We plan to study various modifications in a single chain reaction using long-read sequencing on the MinIon platform from ONT.
People involved: Akash Srivastava
The role of non-coding RNAs in human placental development
Inside the placenta, the fetal syncytiotrophoblast forms the interface between fetus and mother, from which exosomes and microvesicles are permanently released into the maternal circulation. These particles contain fetal proteins and ncRNAs for communication with neighboring and distant maternal cells. The number, size, and content of these particles may reflect or predict placental disorders. Several severe pregnancy pathologies, including preeclampsia, are human-specific and their pathomechanisms are not yet understood.
To date, most examples of ncRNAs that have been identified to be specific for fetal tissues, such as the placenta, are members of the group of microRNAs (miRNAs). Long ncRNAs have only been marginally investigated. We need to expand the knowledge about ncRNAs in the placenta and ncRNAs released from it to revolutionize the understanding of regulation processes inside the placenta and of fetal-maternal communication.
People involved: Sebastian Krautwurst, Milena Žarković, Franziska Hufsky
Collaborations: Udo Markert, Diana Maria Morales Prieto
Grants: DFG MA 5082/9-1: Embryonale nicht-kodierende RNAs in der menschlichen Plazenta und dem mütterlichen Blutkreislauf
Related publications:
Identification of altered miRNAs and their targets in placenta accreta Journal Article
In: Front Endocrinol, vol. 14, pp. 1021640, 2023.
The Role of Non-Coding RNAs in the Human Placenta Journal Article
In: Cells, vol. 11, iss. 9, pp. 1588, 2022.
Identification of miRNAs and associated pathways regulated by Leukemia Inhibitory Factor in trophoblastic cell lines. Journal Article
In: Placenta, vol. 88, pp. 20–27, 2019.
A CRISPR activation screen identifies genes protecting from Zika virus infection Journal Article
In: J Virol, vol. 93, no. 16, 2019.
KL 5 Trophoblast-immune cell communication via microRNA transported in extracellular vesicles Journal Article
In: Pregnancy Hypertens, vol. 9, pp. 5, 2017.
Statistical modeling of genomic and transcriptomic data
In the last two decades in the biotechnological area, one revolutionary advancement was chased by another, leading the life sciences into the big data era. However, besides the availability of vast amounts of different biological data, we still lack sufficient statistical models and methods to accurately process and evaluate these data. We aim to develop specialized statistical tools in the context of genomics (e.g., fuzzy k-meres) and transcriptomics (e.g., accurate modeling of read count distributions). We work on different aspects of statistical analysis, starting from the theoretical problem formulation, to the implementation of statistical models and the appropriate visualization of results.
People involved: Emanuel Barth