Promotor: M. Ubbink, Co-Promotor: R. T. Dame

The genetic information of all living organisms is contained in their DNA. Cells modify the degree of DNA compaction by epigenetics, which largely determines what genes are read out and which genes are transcriptionally silent.

All life on earth contains DNA, which is used to store biological information. Organisms compact their DNA in order for it to fit inside their cell(s).

Promotores: J.N. Kok, H.J. Hoogeboom

Our DNA molecules are packaged by proteins in compact structures. The aim of this project is to understand how modern gene editing techniques nevertheless get access to their target in the DNA.

Identification and characterization of components of DNA repair pathways and their role in Agrobacterium T-DNA integration and repair of CRISPR/Cas induced DSBs.

Promotor: D. Bouwmeester, Co-promotor: D. Kraft

The type-IV secretion system (T4SS) is a machinery able to transfer DNA and proteins between bacteria and in certain cases also to eukaryotic cells.

Promotor: R.D. Gill, F. Taroni

Promotor: P. J. J. Hooykaas Co-promotor: B. S de Pater

Leiden physicist Maarten Kruithof has discovered how our DNA is infallibly able to fold itself and to unfold again. In his dissertation he demonstrates how DNA is folded in a single long, very flexible spiral.

Compact Cinematics challenges the dominant understanding of cinema to focus on the various compact, short, miniature, pocket-sized forms of cinematics that have existed from even before its standardization in theatrical form, and in recent years have multiplied and proliferated, taking up an increasingly…

What is the most effective way to eliminate tumour cells? The DNA repair mechanism could play an important role in increasing the effectiveness of chemotherapy in the fight against cancerous cells. If we are to influence this mechanism, we need fundamental knowledge about how the mechanism works.

In an Advance Online Publication biophysicist John van Noort and others show using magnetic tweezers that DNA is folded in compliant helices of chromatin. This allows enzymes access to the DNA needed for gene expression. Van Noort's research group made the discovery in close partnership with researchers…

Promotor: Prof.dr. T. Schmidt, Co-promotor: Dr. ir. S. J.T. van Noort

Inactivating mutations in BRCA1 or BRCA2 genes predispose to several types of cancer.

Bacteria often experience external challenges, such as changes in environmental conditions or attacks by bacteriophages.

Promotores: H. Schiessel, G.T. Barkema

DNA carries various forms of information. Out of these forms of information the most well-known is classical genetic information.

Single-celled organisms have stiffer DNA than multicellular lifeforms like humans and rice. Theoretical physicists managed to simulate the folding in full genomes for the first time to reach this conclusion. Publication in Biophysical Journal on February 7.

This project aims to assess the risk of spread of antimicrobial resistance genes in the environment derived from currently used synthetic biology approaches in the field of drug discovery.

Theoretical physicist Helmut Schiessel receives an NWO Projectruimte grant of 390,000 euro. He will use this budget to hire a postdoc and a PhD student to continue his research on flexibility of double stranded DNA.

Schneider

The four possible segments A, T, C and G that link together to form DNA molecules, and with their ordering encode genetic information, are not only different in name, but also in their physical and chemical properties.

Dutch researchers have developed a new tool to label DNA for studying chromosomes in live cells. The tool is non-invasive and can be applied in culture but also in living organisms, such as zebrafish embryos. The team published their findings in the journal Nucleic Acids Research.

The Dutch Public Prosecution Service (OM) and the Netherlands Forensic Institute (NFI) want to use private DNA databases in an effort to solve deadlocked murder cases. Bart Custers, Professor of Law & Data Science at eLaw, Center for Law and Digital Technologies, expects that this is permissible from…

Researching DNA material for genetic disorders using the most powerful apparatus. This is what GenomeScan, a company on the Leiden Bio Science Park, does. Master's student Konstantina Konstantinopoulou is doing an internship there. 'It's a world where developments happen really rapidly so it's a fantastic…

John van Noort

The main purpose of DNAmarkerpoint is to better understand the ecology, evolution and biodiversity through the study of ancient- and modern DNA.

A group of single-celled organisms organises its DNA in a similar way to higher organisms such as plants, animals, and fungi. However, the way packaged DNA is read out differs between the two related groups, Bram Henneman discovered. PhD defence on 5 December.

In human cells, a meter-long DNA is condensed inside a micrometer-sized cell nucleus. Simultaneously, the genetic code must remain accessible for its replication and transcription to functional proteins.

According to the LUMC, patients experience 30% fewer serious side effects when medication doses are tailored to their DNA.

Why do opposites attract? According to Karin van der Tuin, researcher at Leiden University Medical Center (LUMC), it could be because of your DNA. The more you differ from one another, the better. She will be testing her ideas at the Lowlands festival Lowlands, where she will subject visitors to DNA…

The DNA of young people is regulated to express the right genes at the right time. With the passing of years, the regulation of the DNA gradually gets disrupted, which is an important cause of ageing. A study of over 3,000 people shows that this is not true for everyone: there are people whose DNA appears…

Self-assembly is an abundant process in nature and is vital to many processes in living organisms.

Throughout all domains of life, from bacteria and archaea to eukaryotes, genomes adopt well-organized three-dimensional structures that can change in space and time to accommodate preferred transcriptional programs for environmental adaptation, the maintenance of cellular identity and differentiation…

Leiden and Jülich researchers discovered an elegant and simple approach to improve the sensitivity of graphene biosensors. These so-called ‘next generation graphene electronic biochemical sensor devices’ are able to detect very low amounts of HIV DNA thanks to their very low electronic noise.

Key research articles and book chapters of the Chromatin group.

The genomic DNA of every organism is organized and compacted in order to fit inside the cell. This is achieved by the joint action of numerous architectural proteins that aid in folding the genome. Genome folding is tightly interconnected with transcription, with genes in certain regions being silenced,…

The Public Prosecutor's Office (OM) and the Netherlands Forensic Institute (NFI) want to use private DNA databases for genealogical research in criminal investigations. The method could be used in serious criminal cases that have stalled and it is already being used in investigations abroad. Whether…

Freshwater is an important resource, but at a great risk of species decline due to habitat loss, pollution and over-exploitation, and invasive alien species.

Leiden theoretical physicists have proven that not only the genetic information in DNA determines who we are, but also DNA’s mechanics. Helmut Schiessel and his group simulated many DNA sequences and found a correlation between mechanical cues and the way DNA is folded. Publication in PLoS One.

The way DNA folds, largely determines which genes are read out. John van Noort and his group have quantified how easily rolled-up DNA parts stack. This costs less energy than previously assumed. Publication in Biophysical Journal.

You pour a scoop of ditch water in the DNA scanner, and voilà: you know exactly which plants and animals the ditch accommodates. Well, it is not that simple yet, but according to PhD candidate Kevin Beentjes, we can already use DNA techniques to monitor the quality of freshwater. For his PhD research,…

PhD student Willem Noteborn has investigated supramolecular structures. These can be useful for the loading of medicines and signalling molecules regarding, for example, cellular differentiation. In his thesis, he describes the functioning of these structures.

What are the principles of genome folding and dynamics in bacteria?

Researchers from Biomon have used DNA-techniques to find 40 different species of fish in the river Dommel. This technique is capable of detecting more species than conventional methods of measuring.

How do forensic scientists deal with complex DNA-evidence found at crime scenes? Giulia Cereda developed new statistical models to analyse them. PhD defense 12 January.

According to a new study by an international team of researchers from the Caribbean, Europe and North America, the Caribbean was settled by several successive population dispersals that originated on the American mainland.