Joseph G. Gall Staff Member Department of Embryology, Carnegie Institution of Washington Adjunct Professor Department of Biology CMDB Graduate Program Faculty B.S. Yale University Ph.D. Yale University

[Research Interests] [Representative Publications]

RESEARCH INTERESTS

Many molecular processes in the cytoplasm take place in or on subcellular organelles, such as the mitochondria, Golgi vesicles, and endoplasmic reticulum. The same is probably true for the nucleus, although, except for the chromosomes and nucleoli, subnuclear organelles have been poorly defined. Our studies concern the role of nuclear organelles in the synthesis and processing of RNA. We concentrate on a structure in the nucleus called the Cajal body, so named because it was first described 100 years ago by the Spanish neurobiologist and Nobel laureate Ramon y Cajal. Until recently very little was known about the Cajal body, but modern microscopical techniques, particular immunofluorescent staining, in situ hybridization, labeling of proteins with green fluorescent protein, and confocal microscopy have brought rapid progress. We now know that Cajal bodies contain many factors involved in transcribing and modifying both pre-messenger RNA and pre-ribosomal RNA. Since neither of these processes itself takes place in the Cajal body, we think that the Cajal body is a site for assembly of factors required for transcription and RNA processing.

We study Cajal bodies in the fruitfly Drosophila and in the giant nucleus, or germinal vesicle (GV), of the amphibian oocyte. In the fly we can study mutations that affect Cajal body organization in various tissues and at different stages of development. In the amphibian oocyte we take advantage of the large size of the nucleus and its organelles to carry out biochemical and microscopical studies that are not possible in the smaller cells of the fly.

The general lesson from our studies is that complex molecular events in the nucleus, like those in the cytoplasm, occur in or on organelles that may be large enough to study by conventional light microscopy. Exactly where these events take place and how the structure of the nucleus contributes to their regulation are important aspects of nuclear physiology.

REPRESENTATIVE PUBLICATIONS

Liu, J-L., and Gall, J. G. (2007). U bodies are cytoplasmic structures that contain uridine-rich small nuclear ribonucleoproteins and associate with P bodies. Proc. Natl. Acad. Sci.104,11655–11659.

Liu, J.-L., Murphy, C., Buszczak, M., Clatterbuck, S., Goodman, R., and Gall, J. G. (2006). The Drosophila melanogaster Cajal body. J. Cell Biol. 172, 875-884.

Handwerger, K. E., Cordero, J. A., and Gall, J. G. (2005). Cajal bodies, nucleoli, and speckles in the Xenopus oocyte nucleus have a low density, sponge-like structure. Mol. Biol. Cell. 16, 202-211.

Deryusheva, S., and Gall, J. G. (2004). Dynamics of coilin in Cajal bodies of the Xenopus germinal vesicle. Proc. Natl. Acad. Sci. 101, 4810-4814.

Handwerger, K.E., Murphy, C., and Gall, J.G. 2003. Steady-state dynamics of Cajal body components in the Xenopus germinal vesicle. J. Cell Biol. 160, 495-504.

Gall, J.G. (2003). The centennial of the Cajal body. Nature Rev. Mol. Cell Biol. 4, 975-980.