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 research presented in this thesis explores the chemotherapeutic potential of metal-based compounds as chemotherapy agents, with an initial focus on the synthesis and DNA interaction studies of platinum and palladium compounds utilizing the [Pt(bapbpy)]2+ scaffold. The study identifies intercalation…

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.

Every organisms in the tree of life faces the same challenge: the length of its DNA exceeds the volume of the cell it needs to fit in. Several strategies have evolved to solve this problem, one of them being the expression of proteins that bind and organize the DNA.

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

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.

Schneider

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…

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.

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 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.

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.

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.

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.

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

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.

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

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.

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

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.

On October 26, the Dutch Embassy in Berlin celebrated the opening of a new research network for Dutch academics in Germany. Dutch minister of Education, Culture and Science Robbert Dijkgraaf gave the starting signal for this new initiative.

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.

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.

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.

Ever since its foundation, Leiden University has turned its gaze outwards to other cultures, languages and forms of academic practice. It is only natural, therefore, that we as a university have four institutes abroad: the Royal Netherlands Institute of Southeast Asian and Caribbean Studies (KITLV-KNAW)…

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?

There is a need for alternative methods to replace, reduce and refine (3R) animal experimentation. Combining experimental data from high-throughput in vitro studies with in silico modeling is a promising approach to unravel the effect of chemicals on living cells and to gain a better understanding of…

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

Dynamics of material, social and ideological relationships in the pre-Columbian insular Caribbean

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.