The objective of the proposed research is to ultrastructurally characterize basic eukaryotic genetic processes: Chromatin transcription, chromatin replication, nascent transcript processing, and mRNA storage and translation. As our major approach we will use a chromatin spreading technique that allows visualization of dispersed nuclear contents in the electron microscope. Biochemical approaches, such as subcellular fractionation, analytical electrophoresis, and recombinant DNA technology, will supplement our investigation.
Our first aim i s to analyze the genetic activity of specific genes. We are investigating the heat shock transcription units of Drosophila, the late transcription units of Adenovirus 2 in infected Hela cells, the expression and structure of Xenopus 5S gene-contining plasmids when incubated in Xenopus nuclei vs a Xenopus nuclear extract, and the expresion of the Herpes virus thymidine kinase gene when incorporated into a recombinant plasmid and introduced int somatic cells. Secondly, we hope to characterize the ribonucleoprotein structure of pre-messenger and messenger RNA. Specifically, we will investigate the RNP ultrastructure and composition of ascent hnRNA transcripts in Adenovirus infected Hela cells, and we will compare the protein composition of sea urichin egg mRNA to embryo mRNA with the aim of characterizing how these molecules are stored for use after fertilization. Thirdly, using both Drosophila embryos and Adenovirus genomes, we will attempt to visualize chromatin that is engaged simultaneously in replication and transcription and to analyze the result of the physical interaction of these two processes. We hope to gain new information on the transcription unit structure and activity of defined genes, the nuclear packaging and processing of hnRNA, the cytoplasmic storage and utilization of mRNA in early development, and the interaction beween transcription and replication.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM021020-10
Application #
3270211
Study Section
Molecular Cytology Study Section (CTY)
Project Start
1977-12-01
Project End
1987-11-30
Budget Start
1985-12-01
Budget End
1986-11-30
Support Year
10
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Virginia
Department
Type
Schools of Arts and Sciences
DUNS #
001910777
City
Charlottesville
State
VA
Country
United States
Zip Code
22904
O'Reilly, M M; French, S L; Sikes, M L et al. (1994) Ultrastructural in situ hybridization to nascent transcripts of highly transcribed rRNA genes in chromatin spreads. Chromosoma 103:122-8
Mougey, E B; O'Reilly, M; Osheim, Y et al. (1993) The terminal balls characteristic of eukaryotic rRNA transcription units in chromatin spreads are rRNA processing complexes. Genes Dev 7:1609-19
French, S (1992) Consequences of replication fork movement through transcription units in vivo. Science 258:1362-5
Hager, E J; Miller Jr, O L (1991) Ultrastructural analysis of polytene chromatin of Drosophila melanogaster reveals clusters of tightly linked co-expressed genes. Chromosoma 100:173-86
Gotta, S L; Miller Jr, O L; French, S L (1991) rRNA transcription rate in Escherichia coli. J Bacteriol 173:6647-9
French, S L; Miller Jr, O L (1989) Transcription mapping of the Escherichia coli chromosome by electron microscopy. J Bacteriol 171:4207-16
Osheim, Y N; Miller Jr, O L; Beyer, A L (1988) Visualization of Drosophila melanogaster chorion genes undergoing amplification. Mol Cell Biol 8:2811-21
Saffer, L D; Miller Jr, O L (1986) Electron microscopic study of Saccharomyces cerevisiae rDNA chromatin replication. Mol Cell Biol 6:1148-57
Osheim, Y N; Miller Jr, O L; Beyer, A L (1986) Two Drosophila chorion genes terminate transcription in discrete regions near their poly(A) sites. EMBO J 5:3591-6
Osheim, Y N (1985) Chorion genes in Drosophila melanogaster. Oxf Surv Eukaryot Genes 2:141-59

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