Bernard Roelen studied Biology at Utrecht University and subsequently performed a PhD study at the Hubrecht Institute (Utrecht) under the supervision of Christine Mummery. After obtaining his PhD degree he was appointed junior researcher at the same institute. Afterwards he worked as a postdoctoral fellow at Massachusetts General Hospital/ Harvard Medical School in Boston (USA). After returning to the Netherlands he worked as a postdoctoral researcher at the Netherlands Cancer Institute in Amsterdam. In 2003 he became Assistant professor and in 2010 Associate professor at the Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University in Utrecht, the Netherlands. His research is focused on mammalian germ cells, early embryos stem cells and. He is author of >70 scientific publications.
Together with Christine Mummery and Anja van de Stolpe he wrote the book ‘Stamcellen’ (in Dutch) published by Veen. In 2011 together with Christine Mummery, Anja van de Stolpe and Ian Wilmut he wrote an English updated version of this book ‘Stem Cells’ that was published by Elsevier. In the same year the book was awarded the ‘Medical Book Award’ by the British Medical Association. Renewed and updated editions of this book, written by Christine Mummery, Anja van de Stolpe, Hans Clevers and Bernard Roelen were published in 2014 and 2021.
Current Research:
Life of all placental mammals starts with an oocyte (egg) that is ovulated from the ovary and subsequently fertilized. Before the oocyte can be fertilized it has to mature from a diploid ‘ primordial germ cell’ to a haploid cell that is ready to receive the sperm cell. This includes a specific type of cell division (meiosis) during which homologous recombination occurs and the number of chromosomes is reduced to one set (haploid). In oocytes meiosis is extremely asymmetrical and leads to only one functional cell and three polar bodies. Although during embryonic development millions of oocytes are formed and stored in the ovaries, only hundreds (in women max ~500) of oocytes are ovulated and have a chance to be fertilized while the large majority degenerates in the ovaries. In my lab the process of oocyte maturation is studied in order to understand how oocyte developmental competence is acquired.
The fertilized egg, called zygote, is a ‘totipotent’ cell’ meaning that it will give rise to the entire organism including extra-embryonic structures such as the embryonic part of the placenta. During the first cleavage divisions the newly formed cells differentiate and lose their developmental competence. At the time of implantation the embryo, called blastula, is composed of trophectoderm, primitive endoderm (hypoblast), and an inner cells mass (epiblast). Only the cells of the inner cell mass can give rise to the fetus, these cells ‘pluripotent’. The other cells form extra-embryonic structures. When cells from the inner cell mass are cultured in vitro they can form pluripotent embryonic stem cells. In my lab we try to understand how cells of early embryos lose, acquire or maintain developmental potency. This includes research on stem cells.
Collaborations:
Prof dr Susana Chuva de Sousa Lopes
Leiden University Medical Center, Leiden, the Netherlands
Prof dr Rene Ketting
Institute of Molecular Biology, Mainz, Germany
Prof dr Andras Dinnyes
Biotaletum, Gödöllö, Hungary
Dr Gabriela Rodrigues
DR Solveig Thorsteinsdottir
Faculty of Sciences, Lisbon University, Lisbon, Portugal
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