Ruth Lehmann, PhD

Laura and Isaac Perlmutter Professor and Chair of Cell Biology; Director of Skirball Institute of Biomolecular Medicine; Director of Kimmel Center for Stem Cell Biology; HHMI Investigator

Lehmann Lab

Cell Biology, Skirball Institute of Biomolecular Medicine




Contact Information

540 First Avenue
Skirball Institute of Biomolecular Medicine
Floor 4, Lab 10-13
New York, NY 10016

Office Tel: (212) 263-8071
Lab Tel: (212) 263-6297
Fax: (212) 263-7760

Admin Contact

Nancy Rodriguez
Tel: (212) 263-2989

Germline Development in Drosophila

Germ cells are the stem cells of the next generation. They are not needed for the vital functions of an organism, but, as sperm or egg, they are key to reproduction. We are interested in three broad questions of germ line development and function. How is the germ cell program established and maintained, how do primordial germ cells (PGCs) interact with their environment during their migration to the somatic gonad and how do germ cells balance threats and opportunities posed by mobile elements and pathogens.

The germ cells program: In contrast to many other cell types of the body that make up the soma no conserved master transcriptional regulator has been identified that is sufficient to specify germ cells. Rather, germ cell specification requires the transcriptional repression of somatic fates and the correct expression or localization of conserved, germline-specific RNA regulators that coordinate germ line programs. Germ cells in Drosophila form within a specialized germ plasm. We are interested in how regulation of germplasm RNAs contributes to germ cell functions and how, after the initial transcriptional block, PGCs initiate a germline-specific transcriptional program.

Soma-Germline interaction. In most organisms, primordial germ cells (PGCs) are set-aside early during embryogenesis. Subsequently, PGCs migrate through the embryo, associate with somatic gonadal cells and form the embryonic gonad. Here, PGCs become germline stem cells that give rise to sperm and egg. PGCs form at the posterior pole of the Drosophila embryo and are carried inside the embryo during gastrulation in juxtaposition to the posterior midgut. From here, PGCs migrate actively toward the somatic gonadal precursors to form the embryonic gonad. We study how the migratory program is initiated, how different signals guide germ cells along the migratory route and finally how germ cells cease migration and associate with the somatic gonad.

Transgenerational defense mechanisms: Germ cells are unique as they have the opportunity to develop into sperm and egg and thereby to contribute to an entirely new generation. We are interested in the control mechanisms that prevent premature differentiation and that detect and eliminate aberrant gametes. We study how germ cells defend against endogenous threats such as transposable elements while keeping the opportunity for genetic change and evolution open. Recent projects are focusing on how germ cells entertain mutualistic interactions with pathogens like Wolbachia.