16 May 2018
What led you to work on mammalian meiosis?
My path towards studying meiosis in oocytes started when I studied biochemistry at the University of Bayreuth in Germany. I did my Diploma thesis with Christian Lehner and Stefan Heidmann. Using confocal microscopy, I investigated how centromeres are propagated in Drosophila embryos. I very much enjoyed using quantitative microscopy to tackle biological problems. I therefore decided to apply to Jan Ellenberg’s lab at the European Molecular Biology Laboratory in Heidelberg for a PhD position, as Jan was a pioneer in the live cell imaging field.
At that time, there were no high-resolution studies of mammalian oocytes, so I felt that it would have lots of potential to develop microscopy methods for live mouse oocytes. Jan gave me a chance to establish these methods, and luckily this worked out nicely. Later, as a group leader at the MRC Laboratory of Molecular Biology, I extended our work to human oocytes.
What particularly fascinated you about microscopy?
I especially like microscopy as an approach because it can be used to observe live and in great detail how a cell works. By combining multi-colour imaging with quantitative image analysis and loss-of-function assays, we can address many of the pressing questions related to oocyte meiosis. Biochemical assays are very challenging in this system, as oocytes are only available in very small numbers. Live cell microscopy is ideally suited to study these rare cells, and to extract as much information from a single cell as possible.
What questions do you try to answer in your lab now?
We are investigating how mammalian eggs develop and why they frequently carry an abnormal number of chromosomes, a condition referred to as aneuploidy. Aneuploidy in eggs is a leading cause of pregnancy loss and several genetic disorders including Down syndrome.
More recently, my lab has started to investigate meiosis and chromosome segregation also in live human oocytes. This has not been possible before and is a new direction of research in my lab that I am very excited about.
To do this work, I set up a small satellite lab in the world’s first in-vitro fertilization clinic, Bourn Hall Clinic, in Cambridge, UK. This clinic was founded by Robert Edwards and Patrick Steptoe, who pioneered in-vitro fertilization for humans. We have set up a light sheet imaging system there that we use to study how chromosome segregation errors arise directly in human oocytes.
Another important topic that we are interested in is why the quality of human eggs declines so dramatically as women get older. Aneuploidy in eggs increases as women get older – this also explains why it becomes more and more difficult for women to conceive as they approach their early 40s. We want to understand the mechanisms behind the decline in egg quality with advancing maternal age.
What drives your passion for research?
For me it’s the ability to discover something new that no one has seen or known before. I also really enjoy the freedom to work on whatever you find most interesting and meaningful.
Of course, I also hope that in the longer term our work will help couples who are finding it difficult to conceive. Infertility is an increasing problem in our society that affects many couples. If we want to improve fertility treatments, we need to know more about why in-vitro fertilization often fails and why it becomes more difficult for women to conceive as they approach their 40s.
What does receiving the EMBO Gold Medal mean to you?
It is an absolute honour to be amongst so many excellent colleagues who received the EMBO Gold Medal in previous years. But the award should really go to the many outstanding postdocs and students I have had the pleasure to work with. None of our work would have been possible without their enthusiasm and dedication to understanding the biology of mammalian eggs and the causes of the maternal age effect.
You were an EMBO Young Investigator and are an EMBO Member. How has that influenced your career?
The Young Investigator Programme is an excellent network for young scientists in Europe. You get to know and exchange with many scientists who are in a similar career stage, and this has been very helpful for my career. As an EMBO member, you continue to be part of this great family, and I look forward to the many more years to come as a member of this wonderful research network.