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

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

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.

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.

Promotor: R.D. Gill, F. Taroni

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

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.

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.

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

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

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).

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

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.

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.

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.

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…

Schneider

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.

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.

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…

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…

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…

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.

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

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.

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.

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.

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

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.

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.

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.

Rapid developments in DNA techniques allow researchers to find out more and more about human genetics. An international group of scientists has drawn up five ethical guidelines to ensure that this DNA research is better regulated. Leiden archaeologist Marie Soressi – one of the signatories - explains…

Campus The Hague has forged its own identity: alongside interdisciplinarity, interaction with the city is its defining feature. ‘The campus is now a young adult. It is well beyond puberty,’ says campus chair Erwin Muller. An ambitious new strategy reveals this.

From 14 to 29 PhD candidates, seven actively involved faculties and, above all, lots of innovative interdisciplinary research, all with data science as the common denominator. The university’s Data Science Research Programme (DSO) has proven so successful that after five years on a start-up grant it…

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.

Large carnivores and humans, along with their livestock, have co-existed for thousands of years. However, human population growth and an increase in economic activities are modifying the landscape for large carnivores and their prey.

How do our cells keep DNA stored away? To find out, biochemist Remus Dame received a 3 million euro Science-Groot grant. Leiden University will share the grant with TU Delft, VU Amsterdam and the Hubrecht Institute.

In the largest study of ancient DNA ever conducted, an international team of scientists has revealed the complex story behind one of the defining periods in European prehistory. The study is published this week in the journal Nature.

How is Pol θ responsible for T-DNA integration, and how do other DNA double-strand break repair pathways interact with Pol θ? How may we manipulate T-DNA integration to stimulate error-free integration at a predetermined genomic site?

PhD Defence

Promotor: J.N. Kok, P.E. Slagboom Co-promotor: J.F.J. Laros

In prehistoric times there was a huge wave of migration, from the steppes in Russia and Ukraine to West Europe. The newcomers’ genes began to dominate. Archaeology research in Leiden into burial mounds in the Veluwe and Utrechtse Heuvelrug areas of the Netherlands yielded this spectacular conclusion.…