Albrecht Sippel - A geneticist with a philosophical touch
Where do humans come from? How do we function? What makes us so special? These are the questions that absorbed Prof. Albrecht Sippel at the University of Freiburg during his time as a biology student. And the same questions have remained on a backburner throughout his exciting career as a researcher. After years of directing his focus more on the molecular processes in the development of different cell types, he has gone back to his roots. Despite his retirement six months ago, Sippel started to actively participate in the search for human genes in the faculties of thought and speech that distinguish us from our animal relatives.
When Albrecht Sippel, who was born in 1942, finished his secondary education there were two main factors to consider. One was his interest in human origin, the other was his desire to become a civil engineer. At school, he had always had an affinity with geometric structures and had always dreamed of building bridges, roads or airports. He finally came to a decision after a period of work experience in motorway construction. “It was then that I realised that civil engineers do not have an easy life,” laughs Sippel who retired from his post as genetics professor at the University of Freiburg last year. “For months, the engineers were housed in tiny, overheated orange boxes”. Instead, Sippel turned his attention to the human question and therefore to biology. He discovered that he was even more fascinated by the geometrical nano-worlds of the cell than the organisational structures of transportation systems.
He wanted to know how humans and life in general work. Back in 1962, molecular biology did not yet exist at any German university, and it was only ever referred to as a footnote in German textbooks. Sippel therefore managed to get hold of American-published books. And as he was the only one of his fellow students who wanted to become a researcher rather than a biology teacher, he became the first 'Diplom' biologist at the University of Würzburg. In 1967, he finally decided to write his diploma thesis under Professor Guido Hartmann who had just returned from a research visit in the USA, a stroke of luck as Hartmann had imbibed the latest trends in molecular biology research in the USA and was aiming to develop these further in Germany.
From Würzburg to Harvard
It took Sippel only three years to complete his diploma and doctoral theses. He investigated the transcription process in great detail, the first step occurring during the translation of DNA into proteins. Even American professors took notice of his work. “They all flocked to our small laboratory in Würzburg,” Sippel recalls. “I was offered a number of postdoctoral positions, including one at Harvard University in the laboratory of James Watson who received the Nobel Prize for the discovery of the double helix in 1962.” And this was the post he accepted. “In America, I learned how research is done,” says Sippel. “In America, nothing was impossible if you had enough self-confidence as well as the strength and ability to assert your own ideas.”
This was followed by informative and particularly innovative years at the Columbia University Medical School in New York. Sippel concentrated on research into the mechanisms of hormone action and was the first to show that thyroxine from the thyroid gland regulates the transcription process. These were the formative years of molecular genetics, and he was at the forefront. In 1975, he returned to Germany to the Max Planck Institute of Molecular Genetics in Berlin and did research into the genes of chicken egg-white proteins that are regulated by steroids. In 1979, he took over as head of an independent research group at the Institute of Genetics at the University of Cologne. In 1983, he co-founded the Centre for Molecular Biology (ZMBH) at the University of Heidelberg, which enabled him to have a major influence on the development of molecular genetics and genetic engineering in Germany.
By now his research had achieved worldwide acclaim. He was the first to discover a protein (transcription factor) in organisms with real nuclei that interacts with specific DNA sequences and thus controls their transcription rate. This protein regulates the gene for the enzyme lysozyme that is active, amongst other places, in the macrophages of the immune system. Lysozyme helps the macrophages to dissolve bacterial intruders. “But I found it difficult to work on this subject effectively at the ZMBH,” says Sippel. “As founding director I had a lot of administrative work to do, and we also had many opponents who virtually demonised genetic engineering.” There were bomb threats as well as aggression at panel discussions, and this additionally hindered creative research.
Back to the major questions
After Sippel had attracted numerous excellent scientists to the ZMBH, no permanent professorship remained for him. “I was completely spent,” he admits. “All this feuding with the public delayed my research. I could have returned to the United States; the German government did far too little to help German basic researchers in this feud.” In 1990, he left Heidelberg and became professor of genetics at the University of Freiburg. He continued to do research into the lysozyme gene through the study of the elementary molecular mechanisms in the development of blood cells. He also worked with embryonic stem cells of mice, long before this kind of research became popular. And finally, he also returned to his original questions. As dean of the Faculty of Biology between 1995 and 1997, he was increasingly involved in interdisciplinary projects. Together with a partner in the humanities, he established the seminar series “Language and Brain” which involved linguists, geneticists and neurobiologists.
“But I achieved my biggest dream when I retired from my position as genetics professor at Freiburg University last year,” says Sippel. He joined Svante Päabo’s group at the Max Planck Institute for Evolutionary Anthropology in Leipzig as visiting researcher. Päabo’s group is researching the genetic particularities of humans, in particular the FOXP2 gene that is implicated in the development of language skills. The human FOXP2 gene differs from that of all other animals and is taken to be a prerequisite for the highly developed speech faculties of humans. In Leipzig, Sippel looked for other genetic factors that make humans unique. He examined around one tenth of all human genes, especially those connected to neurological or cognitive diseases such as depression, schizophrenia and autism and compared their sequences to those of different mammals. He discovered several nucleotide exchanges that are unique to humans and that could be a basis for our special thought processes. Some of these sequence differences are now being examined in more detail in Leipzig.
Sippel himself is gradually withdrawing from the world of active research. “I have much to look back on,” he says. “These are the thoughts that occupy me most at the moment.” He is satisfied with his research career. And he finally has more time for philosophy.
mn – 23.06.08
© BIOPRO Baden-Württemberg GmbH
Prof. Dr. Albrecht E. Sippel
Institute of Biology III
University of Freiburg