This longitudinal study is focused on neurodevelopmental problems in young children with XXY, XXX and XYY, aged 1 to 6 years.

All crested and marbled newts (the genus Triturus) suffer from an unusual genetic abnormality, called a balanced lethal system, that kills exactly half of their offspring. How can a trait so disadvantageous have survived millions of years of natural selection?

The programme of the 3rd International Workshop on Klinefelter Syndrome, Trisomy X, and XYY. International Workshop theme: 'A life-course perspective'

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Promotores: H. Schiessel, G.T. Barkema

How do balanced lethal systems originate and persist in nature?

The relative simplicity of the bacterial cell, short generation times and well defined and inexpensive culturing conditions have significantly contributed to our understanding of many complex biological systems. Yet the workings of the bacterial genome, seemingly impossibly compressed within a tiny…

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My PhD project studies how the temporally sequential Hox gene expression is regulated during head-tail patterning of the frog embryo.

Nucleoid associated proteins maintain the architecture of the bacterial chromosome and regulate gene expression, hinting that their role as transcription factors may involve local three-dimensional chromosome re-modelling.

The role of language in self-regulation and social behavior in children with an extra X chromosome

Chromatin is an ubiquitous protein-DNA complex that forms the structural basis of DNA condensation in all eukaryotic organisms.

The CIGR brings together a diverse range of unique expertise in genome research rooted in biology, chemistry and physics. Members of the CIGR investigate genome folding and genome transactions. An important aspect is direct as well as long term relevance for medicine. The available expertise extends…

Our group operates at the cross-roads of different disciplines: molecular and cellular microbiology, biochemistry, structural biology and biophysics. The group harbors expertise in a multitude of molecular and cellular approaches including:

We warmly welcome late abstracts for Poster Communications! Late abstracts submission closes on the 1st of August 2022.

The group Theoretical Physics of Life Processes, led by Helmut Schiessel, focuses on the physics of chromatin, the DNA-protein complex that fills the nuclei of eukaryotic cells.

Brain development in children with an extra X chromosome as compared to children with autism: evidence from MRI

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

The CMCB brings together a diverse range of unique expertise in microbial cell biology. Members of the CMCB investigate both model and non-model organisms, bacteria and archaea, pathogens and non-pathogens.

Thirty years ago, mutations in the BRCA1 gene were first linked to hereditary breast and ovarian cancer, establishing a genetic basis for cancer development.

The programme group Clinical Neurodevelopmental Sciences is one of the six groups within the Institute of Child and Education Studies at Leiden University. The group participates in all stages of the education programme: the bachelor's, master's and research master's programme.  The group is particularly…

Research in the group Clinical Neurodevelopmental Sciences is focused on understanding and influencing developmental mechanisms in children and adolescents.

TRIXY is a national Center of Expertise, in which clinical professionals and expert researchers work together to improve knowledge and clinical care for children with X and Y chromosome trisomies.

The Leiden Institute of Education and Child Studies aims to conduct high-quality research that addresses major social issues. This inspires its BSc, MSc and PhD programmes.

Actinobacteria are Gram-positive bacteria that have a complex multicellular life cycle and are well known for their ability to produce a wide range of bioactive natural products (NPs).

PhD defence

The CIGR comprises research groups from the Leiden Institute of Chemistry (LIC), the Leiden Academic Centre for Drug Research (LACDR) and the Leiden Institue of Physics (LION).

On this page the programme and sessions can be found.

Key research articles, reviews and books of the Chromatin group.

Mapping of bacterial genomes to combat infectious diseases

Ben Wielstra strives to unravel the evolution of balanced lethal systems. On 1 February he started his own lab at the Institute of Biology Leiden. Wielstra is one of five researchers at Leiden University who has been awarded an ERC Starting Grant in 2018 by the European Research Council. ERC Starting…

The CMCB comprises research groups from the Institute of Biology Leiden (IBL), the Leiden Institute of Chemistry (LIC) and the Leiden University Medical Center (LUMC).

The researchers at the Institute of Education and Child Studies focus on child rearing and the development of children and adolescents with and without developmental and other problems, in biological and non-biological families, childcare, education and care institutions.

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…

There is greater variety in the size of men’s brains than of women’s. This could help explain why some psychiatric disorders such as ADHD and autism are more prevalent in boys. Leiden brain researcher Lara Wierenga has published an article about this in the international journal Cerebral Cortex.

Producing offspring of a crop without sowing and that is even bigger than the parent plant. According to Leiden researchers this can be achieved by overstimulating a single gene that rejuvenates cells, including bringing them back to the embryonic phase.

Within the same species of butterfly many different wing patterns can occur. How is this possible? According to researchers Ben Wielstra and Emma Berdan, of the Institute of Biology Leiden (IBL), the answer lies within supergenes. A supergene is a part of a chromosome that contains many strongly linked…

With the aid of physics and a minuscule magnet, researchers have discovered a new structure of telomeric DNA. Telomeres are sometimes seen as the key to living longer. They protect genes from damage but get a bit shorter each time a cell divides. If they become too short, the cell dies. The new discovery…

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.

Ben Wielstra studies balanced lethal systems, in which half of the offspring die before birth. In the journal Current Biology, he explains in an accessible way how such a disadvantage can originate in nature.

An evolutionary 'trap' that has haunted crested and marbled newts for 25 million years: Leiden researchers have uncovered a mysterious DNA error that should not be able to arise – yet persists all the same. How is that possible? PhD candidate James France found new clues.

For the first time, it was shown in living cells how the bacterium E. coli regulates genes that help it survive in a new environment. Biochemist Fatema Zahra Rashid managed to do this using a technique she fine-tuned. Her research into changes in 3-dimensional chromosome structure offers clues for ways…

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,…

We investigate the processes underlying the patterns. We aim to explain biodiversity by investigating the distribution, function, development, and evolution of body forms, as well as physiological and behavioural variety among species. We collaborate with those specialized in describing, archiving,…

Ben Wielstra and his team have received a ENW-M-1 grant. This grant of 354.000 euros is awarded by NWO, and will enable the researchers of the Institute of Biology Leiden and Naturalis to continue their evolutionary newt research.

Leiden scientists are the main applicants for five projects that have been awarded a Science Groot grant of up to 3 million euros in the Science Domain. In addition, several Leiden scientists are involved in other projects that have been awarded funding.