Terminal deficiency associated PEV (TDA-PEV) modifier genes and their implication in chromosome and nuclear organization in D. melanogaster

• Applicant: Dr. Patrick Heun
• Subject Area: Cell Biology
• Term: from 2001 to 2003
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5350159

Despite the growing amount of evidence that chromosome position and nuclear organization play the key role in gene expression in a wide variety of organism, surprisingly little is known about the components and mechanisms responsible for this organization. To identify the cis and trans-acting components responsible for long-distance regulation of gene expression, the Karpen laboratory has performed a genetic screen for modifiers of a position effect variegation (PEV) system in Drosophila. Based on the cis-mediated repression on a terminally-deficient minichromosome, also known as Terminal DeficientyAssociated PEV (TDA-PEV), this system putatively involves telomere behavior and chromosome position in the nucleus. The screen has succesfully identified unique mutations in genes likely involved in telomere structure and function, or other mechanisms responsible for nuclear organization. The aim of my research proposal addresses the following questions: 1) Does TDA-PEV involve nuclear positioning and 2) What are the biological functions encoded by TDA-PEV modifier genes? To study theses questions I will use fluorescence in situ hybridization (FISH) combined with general cytological analysis of endogenous chromosome behaviour in modifiers of TDA-PEV. Interesting phenotypes will be chosen for molecular cloning and studied in more detail for their normal gene function.

• DFG Programme: Research Fellowships
• International Connection: USA
• Cooperation Partner: Professor Dr. Gary H. Karpen