While growing up in the 1960s in Cologne, Germany, Ruth Lehmann developed a passion for math—one her father, an engineer, and her mother, a teacher, strongly encouraged. “My mother in particular put a lot of thought into educating my brother and me pretty equally,” she says. “The idea that I was interested in math was never a problem.” In high school, Lehmann developed a parallel interest in science after taking a biology class from a particularly inspiring teacher. “He got us excited about discovering new things, not just about learning the names of plants and things,” she recalls. When she entered the University of Tubingen in 1974, Lehmann chose biology as her major, but was disappointed in her classes. Her professors, she remembers, “were mostly just reading from their textbooks.”
Not sure of what area of science to pursue after graduation, Lehmann applied for—and received—a Fulbright scholarship to study ecology at the University of Washington in Seattle. Once there, she realized she was more interested in genetics than ecology and soon joined the lab of developmental biologist Gerold Schubiger, who was researching the developmental genetics of the fruit fly (Drosophila). “I couldn’t have been introduced to the fruit fly at a better point in time,” she recalls. “The field of fly developmental genetics was just starting to explode.” Toward the end of her fellowship, Lehmann attended a conference presentation by the developmental geneticist (and later Nobel Prize laureate) Christiane Nüsslein-Volhard on what was then known about the genetic mechanisms that give early embryos their shape and pattern. Fascinated by what she heard during that talk, Lehmann decided that developmental genetics—studying how fertilized egg develops into a multicellular organism able to transmit genetic information across generations—was the field of research she wanted to pursue.
On the advice of Nüsslein-Volhard, Lehmann returned to Germany, where she received her graduate studies and diploma degree (the equivalent of a master’s degree) under the tutelage of developmental neurobiologist Jose Campos-Ortega at the University of Freiburg. For her PhD, Lehmann went back to the University of Tubingen, with Nüsslein-Volhard, who had recently established a lab there, as her advisor. In that lab, Lehmann searched for—and found—mutations in many years and specifically pursued three genes (oskar, nanos, and pumilio) that led to defective cell fate patterns during the embryonic development of Drosophila. By studying these genes (and later others), she identified the specific role that oskar played in organizing the pathway that determined the positioning of germ plasm within the embryo and the role of Nanos and Pumilio as regulators for embryonic pattern and germ cell specification. This research contributed to the first genetic framework for the specification of germ cell fate in any organism.
Molecular tools were just becoming available to geneticists in the early 1980s. “I quickly realized I would have to become a molecular biologist,” Lehmann recalls. So, for her postdoctoral training, she went to the laboratories of Michael Wilcox and Peter Lawrence at the Medical Research Council in Cambridge, England, where she learned how to clone genes to identify their DNA sequence and determine their molecular function. Armed with these new skills, she returned to the United States, where she took a faculty position at the Massachusetts Institute of Technology and became a member of the Whitehead Institute for Biomedical Research. Eight years later, she moved her lab to the Skirball Institute of Biomolecular Medicine at New York University (NYU). In 2020, she moved back to the Whitehead Institute as its director and president. She continues to teach cell biology, both at MIT and, as an adjunct professor, at NYU’s Grossman School of Medicine.
Over the past three-plus decades, Lehmann has become an internationally recognized leader in the germline field, making many landmark discoveries. In addition to her early findings regarding the genes involved in germ plasm assembly in Drosophila, Lehmann has identified key molecular mechanisms behind the signalling pathways that regulate different stages of germ cell migration. She discovered, for example, that the translation of maternal effect genes is dependent on the localization of their messenger RNA (mRNA), which, in turn, regulates germ cell specification. She also identified the mechanisms underlying mitochondrial inheritance—specifically, that mitochondria (tiny organelles that fuel the operation of the cell) are sequestered in the posterior of the embryo where germ cells develop, ensuring the faithful transmission of mitochondria via oocytes (female germ cells). More recently, Lehmann’s lab has described the mechanism by which only the “best” mitochondria are passed on from the mother to offspring. By visualizing germline selection for the first time, her lab showed that mitochondrial fragmentation followed by mitophagy (degradation of the organelles) drives the selective removal of deleterious genomes during oogenesis and allows the most fit mitochondrial genome to make it to the next generation. These findings are helping scientists develop a better understanding of the transmission of human mitochondrial diseases.
Lehmann has received numerous honors and awards for her work, including memberships in the National Academy of Sciences and the American Academy of Arts and Sciences. She was a principal investigator of the Howard Hughes Medical Institute at MIT from 1990 to 1996 and at NYU from 1997-2020. Lehmann is a renowned mentor, having taught—and inspired—a generation of developmental geneticists, many of whom are internationally known scientists in their own right. She lives in Boston with her long-time partner, neurobiologist Steven Burden, PhD. When she’s not in her lab Lehmann enjoys hiking with her Aussie Luke in the Berkshires. “It’s a really good way of clearing and focusing your mind,” she says.