Walter Gehring (1939–2014)

I arrived in Basel, Switzerland, in 1982 wearing sunglasses and a Hawaiian print shirt and was nervous about my first encounter with Walter Gehring. He was stern and serious and strangely unmoved by the neurotic Jewish humor of a lowly rookie postdoc. As a prank, I used a charcoal-activated straw to drink the tap water. Walter was not amused. This antipathy turned to near rage when he found the butt of my brand of cigarette inside the eyepiece of his coveted Zeiss microscope (I think I was framed). So, it is fair to say that Walter and I were oil and water, but it is nonetheless my privilege to write this memorial on the sad occasion of his untimely death on 29 May following a traffic accident in Greece. Walter studied zoology at the University of Zurich where he received his Ph.D. in 1965. He trained in the laboratory of the great developmental geneticist Ernst Hadorn where he worked on the development of antennae in the fruit fly Drosophila and distinguished himself as a brash scientific talent. The Hadorn lab studied transdetermination of Drosophila imaginal discs, a process whereby disc cells can undergo wholesale changes in identity to produce a different adult appendage. The lab featured a star-studded cast of future fly immortals that also included geneticists Antonio Garcia-Bellido and Gerold Schubiger (who sadly died in 2012). Hadorn himself had trained with Fritz Baltzer and Curt Stern, and thereby represented a rare fusion of classical genetics and experimental developmental biology. Walter went on to conduct postdoctoral research at Yale University with my Ph.D. advisor, Alan Garen, one of the pioneers of bacterial molecular genetics and an early practitioner of Drosophila molecular biology. Between his Ph.D. and postdoctoral training, Walter obtained a broad exposure to molecular genetics and classical developmental biology. His keen sense for interesting developmental processes positioned Walter on the fast track of discovery. As a postdoc, he and Lily Chan (a graduate student in the Garen lab) obtained evidence that the fate map of the adult fruit fly was already established in the early embryo. His obvious abilities led to rapid advancement to an independent faculty position at the Yale Medical School in 1969. Walter recruited future Nobelist Eric Wieschaus as his first graduate student, and hence began the long string of talented scientists who trained in the Gehring lab over a span of about 40 years. ![Figure][1] PHOTO: BIOZENTRUM UNIVERSITY OF BASEL After a few years, Walter moved from Yale to the University of Basel at the newly established Biozentrum. In the late 1970s to early 1980s, his lab was among the first to combine the emerging tools of molecular biology with classical Drosophila genetics to isolate and characterize genes such as Antennapedia , which promotes the formation of legs and suppresses the development of antennae in the thorax. During the 1980s and 1990s, the Gehring lab produced a dizzying array of discoveries: the homeobox, a 180–base pair sequence that encodes a DNA binding domain regulating a variety of developmental processes; the enhancer trap, a valuable technique in molecular biology for identifying tissue-specific regulatory sequences (enhancers) that control gene expression; and eyeless (encoded by PAX6 in human), a key regulatory gene for eye development whose misexpression dramatically induces fly eyes to grow on wings, legs, and antennae. Walter was a naturalist at heart. He was a bird watcher and amateur marine biologist. He quoted Darwin and recognized the implications of his research in the broad context of evolution. Perhaps his greatest talent was his intuitive sense for interesting research problems, combined with a remarkable ability to explain the most complex data sets as a simple story with a clear punch line. These syntheses were often accompanied by fanciful embellishments, but in the process he unlocked the mysteries of highly specialized information and rendered them plain and accessible to everyone. It is largely due to these efforts that the homeobox is widely known and taught in biology classes around the world. Walter's talents won him many awards, including the Kyoto Prize for Basic Science (2000) and the Balzan Prize for Developmental Biology (2002). He was elected a foreign member of the U.S. National Academy of Sciences and the Royal Society of London. An amazing group of students and postdocs was attracted to the Gehring lab over the years: Eric Wieschaus (Nobelist), Christianne Nusslein-Volhard (Nobelist), David Ish-Horowicz, Spyros Artavanis-Tsakonas, Paul Schedl, Alex Schier, Georg Halder, Hugo Bellen, and Markus Affolter, to mention just a few. I worked closely with two of my future lifelong friends and colleagues: Ernst Hafen and Bill McGinnis. The lab was an absolute blast, but a strange mix of anarchy and oppression. Walter permitted considerable independence, but was hardly laissez-faire. He could be confrontational, and did not hesitate to call us out (particularly me) when he felt we were misbehaving. I found Walter to be a complicated character. He had the mannerisms of an authoritative Herr Doktor Professor, but was also folksy and unaffected and always ready to laugh and joke. He sometimes felt competitive with his students and postdocs, but was also highly supportive and proud of our independent careers. In short, I believe the key to Walter's success was his yin and yang embodiment of old-world scholar and modern competitive scientist. He was able to exude charm and empathy, but nothing we did seemed to be quite good enough. In other words, tough love, possibly the perfect prescription for eliciting the very best efforts from his students and postdocs. [1]: pending:yes