[4] After realizing that she preferred genetics and mathematics to ecology, she connected with Gerold Schubiger, a geneticist studying fruit fly development in Seattle, Washington where she learned classical developmental biology.
As Nüsslein-Volhard was moving to an independent position at the European Molecular Biology Laboratory in Heidelberg, which was not associated with a graduate program, she referred Lehmann to José Campos-Ortega, a researcher at Freiburg University studying the neurobiology of Drosophila [5].
[6] Lehmann then moved to the Skirball Institute of Biomolecular Medicine at New York University in 1996 as the Laura and Isaac Perlmutter Professor of Cell Biology.
[3] She was also named a Howard Hughes Medical Institute Investigator and was elected to the American Academy of Arts and Sciences, as well as the European Molecular Biology Organization.
[13][14] Lehmann published her first paper in 1981 under her Fulbright Fellowship mentor Campos-Ortega, detailing her study of early neurogenesis in Drosophila and the effects of lethal mutations on neural and epidermal cell precursors.
[16][17] Using molecular cloning techniques, she discovered that oskar and nanos RNA transcripts regulate gene expression and germ cell formation by localizing at the posterior embryonic pole.
[18][19] Her later work continues to build on this discovery by analyzing modification mechanisms of RNA transcript production and how they affect germ cell differentiation and localization in Drosophila.
She played a substantial role in the discovery of germ cell migratory pathways (namely those involving gap junctions, G protein-coupled receptors like Tre-1, and isoprenoids), particularly those concerning migration into the ovaries and testis.