Abstract: Series 101, Lecture 2
The Harvey Lectures Series 101 (2005—2006)
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Lecture #2: Wednesday, November 16, 2005 — Time and Location
Germ Cells Are Forever
Ruth Lehmann, PhD
Julius Raynes Professor of Developmental Genetics
Investigator, Howard Hughes Medical Institute
Skirball Institute of Biomolecular Medicine
Howard Hughes Medical Institute, New York University School of Medicine
New York, New York
In most organisms, primordial germ cells (PGCs) are set-aside early during embryogenesis. Subsequently, PGCs migrate through the embryo, associate with somatic gonadal cells where they eventually mature into egg and sperm. While PGCs seem highly specialized, their products are the ultimate stem cells that generate a complete organism generation after generation. Our long-term goal is to functionally dissect the germ cell life cycle in Drosophila. So far our genetic studies indicate that germ cell specification requires transcriptional silencing of the future germ cell nucleus and repression of the somatic cellularization program. We find that lipid signaling plays a critical role during PGC migration. Lipid distribution within the embryo and lipid uptake by PGCs provides timing and directionality to migrating PGCs. Finally, our studies support the idea that there is a surprising equivalence among the gene functions that control stem cell potential in PGCs and adult germ line stem cells, providing further means for the functional dissection of the “germ genomeâ€.