Max Planck director honoured for the discovery of genomic imprinting
Davor Solter.
© Douglas Vernimmen
To the point
- Awarded: Davor Solter, Max Planck Emeritus, is receives the 2026 Paul Ehrlich & Ludwig Darmstaedter Prize together with Azim Surani for their "discovery of the phenomenon of genomic imprinting".
- Basic rule of genetics: Our genes are packed together in chromosomes in the nuclei of our cells. Each germ cell (egg or sperm) contains 23 chromosomes. Each body cell contains a double set of chromosomes. One comes from the mother's germ cell, the other from the father's germ cell. All body cells therefore contain two active copies of the same gene.
- Discovery: In 1984, Davor Solter and Azim Surani overturned this rule as they discovered independently of each other that some genes are only inherited in one active copy - either the maternal or the paternal copy is permanently deactivated.
- New field of research: With this phenomenon called "genomic imprinting", they opened the door to epigenetics. Today, it is a central pillar of biomedical research.
Davor Solter, Director at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg, now emeritus, is awarded the 2026 Paul Ehrlich & Ludwig Darmstaedter Prize. Solter received the prize together with Azim Surani, Director of the Wellcome Trust Cancer Research UK/Gurdon Institute in Cambridge, UK, for their "discovery of the phenomenon of genomic imprinting," according to the Paul-Ehrlich-Foundation in Frankfurt. The prize will be awarded on March 14, 2026 by the Chairman of the Board of Trustees of the Paul Ehrlich Foundation in Frankfurt's Paulskirche.
Solter, a physician and molecular biologist, conducted research on the development of mammals. He investigated the genetic and molecular mechanisms that ensure that genetic material is properly activated so that the embryo can develop normally. In groundbreaking experiments in the 1980s, still at the Wistar Institute in the USA at the time, he, along with Surani in Cambridge, UK, independently discovered the phenomenon of so-called genomic imprinting.
This discovery was pivotal for advancements in epigenetics and the understanding of mammalian development, as it was the first to show that parental chromosomes retain a "memory" of their origin. Solter and Surani thus opened the door to epigenetics, the field of research that demonstrates that we are not just the product of our DNA, but that our DNA is influenced and regulated by numerous other factors."This discovery was a turning point in modern genetics. It showed that our phenotype is not determined solely by our genotype, but is also influenced by epigenetic marks. This has fundamentally changed our understanding of health and disease," according to the Paul Ehrlich Foundation.
Consequently, their work also made a significant contribution to understanding various human diseases, such as Prader-Willi syndrome and Silver-Russell syndrome. Beyond developmental disease, imprinted genes also influence signaling pathways that shape health and illness. For example, later-life disruptions of genomic imprinting are seen in colorectal cancer, glioblastoma, and pediatric kidney tumors.
What is genomic imprinting?
During the reproductive process, mammalian offspring receive two copies of the majority of genes, with one copy originating from each parent. Typically, both copies are active, which allows a healthy gene copy to compensate for the effects of a harmful mutation on the gene copy inherited from the other parent. However, Solter and Surani discovered that in a few specific genes, known as "imprinted genes", this is not the case. In these instances, only one copy is active, either the paternal or maternal copy, while the other is turned off.
If the active copy of an imprinted gene is mutated, it can result in developmental disorders, malformations, or increased mortality. To date, over 200 imprinted genes in humans have been identified. Errors in imprinting have been linked to a range of developmental disorders and behavioral abnormalities.
Genomic imprinting is linked to numerous genetic and epigenetic diseases, including Beckwith-Wiedemann syndrome and Angelman syndrome. Furthermore, genomic imprinting plays a pivotal role in mammalian development, particularly during embryonic development, placenta formation, and fetal nutrient supply. Additionally, it influences other crucial areas of mammalian biology, including metabolism, brain development, and behavior. There is mounting evidence that imprinting errors can increase the risk of diseases such as obesity and cancer. Other effects include the preservation of stem cells, regulation of body temperature, and nutritional status.
How to discover an epigenetic process?
Forty years ago, Surani and Solter demonstrated in separate studies in mice that both parental genomes are necessary for mammalian offspring to be viable. A newly fertilized mouse embryo contains two pronuclei: one from the sperm and one from the egg, each containing a copy of the genome. Through the use of then groundbreaking micromanipulation techniques which Solter had previously developed and improved, the pronuclei were transferred from donor to recipient embryos to create reconstructed embryos with either two copies of the paternal genome (bipaternal) or the maternal genome (bimaternal), or with one copy of each.
The bipaternal embryos failed to develop properly, while the bimaternal embryos formed correctly but exhibited poor development of the extraembryonic tissues, which are essential for development. Only the manipulated embryos containing the chromosomes from each parent developed normally and resulted in viable and fertile offspring. The researchers concluded that maternal chromosomes contain information absent from the paternal set, and vice versa. Consequently, normal development requires the full complement of both parental genomes. However, some genes are active only when inherited from the mother, others only from the father. These were called "imprinted genes".
These experiments demonstrated that the two parental genomes are not functionally equivalent and that each copy carries specific "imprints." More details on the discovery in background essay "It takes both parents" by the Paul Ehrlich Foundation
Epigenetics - more than the sum of our genes
The discovery that maternally inherited genes function differently than paternally inherited ones revealed that, in addition to genetic information, non-genetic factors are also passed down, which affect the phenotype in different ways. The underlying cause of genomic imprinting was eventually identified as a series of epigenetic modifications. These modifications, known as methylations, are chemical markers added by the mother or father to the genes. They serve to imprint a "memory" of their origin into the parental genetic material, regulating the activation or silencing of imprinted genes throughout life. Additionally, they play a pivotal role in mammalian development, growth, behavior, and diseases.
This discovery in 1983 transformed the way scientists viewed gene regulation and inheritance, marking a pivotal moment in the development of the field of epigenetics. Today, science has identified numerous additional epigenetic mechanisms that regulate the activity of specific genomic regions and function as crucial regulators of gene expression. The manner in which these diverse layers of information interact, their impact on health and disease, and their role in shaping species evolution remain subjects of ongoing research and debate. However, their origins can be traced back to the experiments of Solter and Surani.
CV Davor Solter
Davor Solter was born in 1941 in Zagreb, Yugoslavia. He received his M.D. in 1965 and Ph.D. in 1971 from the University of Zagreb. Between 1973 and 1991, he served as a professor at The Wistar Institute of Anatomy and Biology in Philadelphia, USA, and became Wistar Professor of Biology at the University of Pennsylvania, USA in 1984. In 1991, Solter was appointed Max Planck Director at the MPI of Immunobiology and Epigenetics in Freiburg, Germany, heading the Department of Developmental Biology until 2006. From 2008 to 2013, he held a professorship at the National University of Singapore as part of a partnership with Duke University and became a Research Director of the Institute of Medical Biology at A*STAR in Singapore. Since 2014, he has been a Visiting Professor at the Faculty of Medicine of Mahidol University in Bangkok, Thailand. Davor Solter is the recipient of several international awards, including the March of Dimes Prize in Developmental Biology (1998), the Rosenstiel Award (2007) for outstanding work in Basic Medical Research by Brandeis University, Boston (USA), the Canada Gairdner International Award (2018), the Mendel Medal by the Genetics Society (2022) and the Clarivate Citation Award (2024).
Davor Solter contributed significantly to many areas of mammalian developmental biology, namely: differentiation of germ layers; the role of cell surface molecules in regulating early development; biology and genetics of teratocarcinoma; biology of embryonic stem cells; imprinting and cloning. In addition, he focused on research into the genetic and molecular mechanisms of genome reprogramming and the activation of the embryonic genome.
The emeritus Max Planck Director led the Department of Developmental Biology from 1991 until 2007. Davor Solter lives in Bar Harbor (Maine, USA).
