Juliane Glaser is the newest group leader at MPI in Freiburg
The French scientist studies epigenetic mechanisms of embryonic development with a focus on “jumping genes”
Meet Juliane Glaser who has joined the Max Planck Institute of Immunobiology and Epigenetics in Freiburg as a group leader. Her research focuses on the role of transposable elements in embryonic development, employing advanced techniques to explore their impact on gene regulation and disease mechanisms. Learn more about her research and her career path in this article and interview.
The Max Planck Institute of Immunobiology and Epigenetics (MPI-IE) is pleased to announce the arrival of Dr. Juliane Glaser who started her new independent research group in June 2025 in Freiburg. The Glaser lab will investigate the impact of transposable elements (TEs) on embryonic development in mammals.
Nearly half of all human DNA consists of transposable elements, mobile genetic sequences often called “jumping genes.” Many of these are remnants of ancient viral infections that have become embedded in our genome. The potential impact of these sequences was first recognized by Barbara McClintock, who discovered transposable elements in maize in 1948 and proposed that they act as “controlling elements” of the genome. Although her insights were initially met with skepticism and these sequences were long considered functionless “genetic parasites,” research over time confirmed their importance, and McClintock was awarded the Nobel Prize in 1983. Today, it is well established that transposable elements, which can repeatedly copy themselves and move to different parts of the genome, play critical roles in gene regulation, development, and disease.
INTERVIEW with Juliane Glaser
Could you describe your current area of expertise and discuss how it has evolved over the past few years?
My lab is interested in the genetic and epigenetic control of embryonic development, with a focus on transposable elements. I trained as a molecular biologist and geneticist, and early on became passionate about developmental biology and never stopped being amazed by the fact that a single fertilised cell differentiates into a multitude of specialised cell types and organs. My first lab experience got me interested in mouse development and gene regulation. During my Ph.D at the Institute Curie, I studied the mechanism of genomic imprinting, a fascinating process by which a gene gets expressed by only one of the two parental alleles. I gained expertise in epigenetics, genome engineering and continued working with the mouse model. For my postdoc, I wanted to pursue studying developmental mechanisms in the context of pathological phenotypes and gain expertise in the field of 3D genome organisation. This is also where I started to study transposable elements and realised how amazing they are! Most of my PhD lab was working on transposons, so I was constantly surrounded by this topic, even if it wasn’t my focus at the time. Then, in my postdoc lab, no one was working on transposons – except me! But that turned out to be beneficial for me to build my niche within my postdoc lab, and I could draw on the expertise and inspiration I had absorbed from my previous colleagues.
You focus your research on mobile genetic elements and their influence on development. In your most recent study soon to be published in Nature Genetics (preprint), you show how the activation of a single, normally silenced retroviral element, in the mouse genome can lead to developmental abnormalities. What fascinates you about these topics and what are your future plans in Freiburg?
When I started to work on this developmental malformation caused by a transposable element (TE), we hypothesised that it was influencing 3D genome organisation and gene expression. This was a logical explanation as TEs were shown to impact gene regulation in different contexts. But we rapidly realised that it was not the cause of the observed pathological phenotype and started to explore other hypotheses. This is where I realised how diverse the impact TEs can have in a cell! One of the hypotheses was that, since this specific TE is inherited from a virus and has retained similar sequences, it could produce a toxic viral-like particle. Back then, I thought this idea might be a bit too crazy… but absolutely not, it ended up being exactly the mechanism. That is what is amazing with research on TE, it never stops surprising you! Here in Freiburg, we will explore similar and other mechanisms by which de-silencing retroviral elements can affect development or even be an integral part of physiological developmental processes.
Speaking of Freiburg: You did your PhD in Paris, your Postdoc in Berlin and now as a MAX Planck free-floater you decided to go to Max Planck in Freiburg. What made you choose Freiburg and the MPI-IE?
People often get surprised when I say that I moved from Paris and Berlin to Freiburg! I’ve always considered myself “a big city person” – I was even born in Paris. So, at first, I was unsure about how I would like living in a smaller city like Freiburg. But after visiting a few times, I really came to appreciate it. Freiburg is a dynamic city, I enjoy the fact that I can bike everywhere, and the nature around is beautiful. More importantly, I chose Freiburg because I felt the MPI-IE would be the best place for me to start my lab. The scientific expertise, the facilities and the diversity at the institute inspired me. I was also very excited that three other Independent Group Leaders were starting around the same time as it created a sense of community and momentum that I still see as a key strength.
Which research technologies and model organisms do you use for your studies?
Although developmental biology can be studied in various model organisms, I have spent my entire career working with mice. Much of my work is conducted in vivo as I aim to understand how specific genomic sequences influence physiology and phenotypes. We use mouse embryonic cells, which we modify using CRISPR/Cas9 technologies, and subsequently generate mouse embryos through the tetraploid complementation technique. This method produces embryos entirely derived from the edited stem cells, facilitating the study of developmental phenotypes without the need to generate adult animals. In parallel, we will also differentiate embryonic stem cells into embryo-like structures, such as gastruloids, which model, in vitro, the first steps of post-implantation development. Finally, we combine these tailored stem cell and in vivo mouse models with omics and imaging technologies.
What inspired you to pursue a career in science?
To be honest, I did not had a clear plan or always knew that science was what I wanted to do. Back in school, I didn’t particularly enjoy most classes and wasn’t exactly an amazing student. I chose to study biology somewhat by default – since it was the subject in school I liked the most – or disliked the least (laughs). It wasn’t until university that I fell in love with biology and realised I wanted to pursue a career in science. For the first time, I enjoyed sitting in class and I had some great teachers who not only taught us the theory but also gave us a glimpse of what it means to be a researcher and the kind of questions they ask and how they go about answering them. I really liked this part, and liked it even more once I got to work in a research lab myself. I found it deeply satisfying to tackle a biological question by designing the best experiments for it, putting results into context and bringing new knowledge to the field. I also discovered how much I enjoy mentoring students in the lab and helping them grow as scientists.
What is the most valuable piece of advice you have received related to your scientific career, and how has it influenced your approach to research?
When choosing a place to work, the environment and your colleagues are almost as important as the scientific topic. The research we do is done in a team, and being surrounded by good colleagues can, at least to me, change everything in your career and your general well-being. I was lucky to be surrounded by fantastic people, and I value having a cohesive and diverse team of people to work with.
Studying the dual nature of transposable elements
“We are fascinated by these elements. The central challenge lies in the dual nature of transposable elements,” says Juliane Glaser. “While their mobility can trigger insertional mutations that can lead to disease or severe developmental abnormalities, many have been co-opted by the genome to serve essential physiological functions. They play key roles in gene regulation and influence cell states; in fact, they can be an integral part of normal developmental processes.”
This delicate balance, particularly during early development, is maintained by epigenetic mechanisms. The Glaser lab aims to investigate these mechanisms and wants to uncover how transposable elements contribute to a later phase of mammalian embryo formation. The new group’s primary goals are to characterize novel disease mechanisms associated with the reactivation of transposable elements, explore their role in embryonic cells’ fate decisions, and decipher the regulatory networks controlling their expression.
From Paris to Berlin to Freiburg
To achieve this, the lab will employ a state-of-the-art approach combining CRISPR/Cas9 genome engineering in mouse embryonic stem cells with the generation of highly specific transgenic mouse models. These models will be analyzed using advanced technologies, including single-cell sequencing and high-resolution imaging, to dissect the molecular and morphological impact of transposable elements during development.
Juliane Glaser is a molecular biologist who joins Freiburg with a strong background in epigenetics, genome engineering, and developmental biology. Her scientific journey from a PhD in Paris focused on genomic imprinting to a postdoctoral fellowship in Berlin investigating the non-coding genome in the context of developmental diseases has provided her with a unique perspective on the complex roles of transposable elements and embryogenesis.
Welcome, Juliane!
CV Juliane Glaser
Juliane Glaser studied Molecular Biology and Genetics at Paris-Cité University in France and continued a with a Ph.D. at the Institut Curie in Paris, where she investigated the epigenetic regulation and physiological impact of genomic imprinting under the supervision of Deborah Bourc’his. Her doctoral research demonstrated that transient transcription during early mammalian development can epigenetically program the activation of an imprinted gene critical for postnatal feeding and growth.
Juliane then secured independent postdoctoral funding from the Human Frontier Science Program (HFSP) and joined the lab of Stefan Mundlos at the Max Planck Institute for Molecular Genetics in Berlin. There, she focused her research on understanding the role of the non-coding genome in developmental disorders. She investigated how structural genomic variations, including inversions, duplications, and the insertion of transposable elements, impact gene regulation during development and contribute to disease.
In 2024, Juliane was appointed as a Group Leader at the Max Planck Institute of Immunobiology and Epigenetics (MPI-IE) and officially launched her lab in June 2025.
