Control of functional complexity by trans-splicing in Drosophila

• Applicant: Dr. Rainer Dorn
• Subject Area: General Genetics and Functional Genome Biology
• Term: from 2006 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 25514918

The complex locus modifier of mdg4, mod(mdg4), in Drosophila is a model system to understand functional complexity generated by the process of mRNA trans-splicing in higher eukaryotes. mod(mdg4) encodes a protein family of 31 isoforms, which are involved in chromatin structure and function. We have demonstrated that all mod(mdg4) isoforms contain a common N-terminal, but variable isoform specific C-terminal protein parts, which mediate isoform specific targeting in chromatin. Genetic and immunocytological analyses indicate specific functions of individual isoforms in control of insulator elements, interband organisation, chromosome pairing and telomere structure. A large collection of genetic material and antibodies will be used to analyse the differential control of chromatin organisation by mod(mdg4) protein isoforms. The complexity of mod(mdg4) is resolved by alternative mRNA trans-splicing, a process identified in a growing number of organisms. We will use a sensitised in vivo assay system to systematically identify and dissect genetic factors involved in trans-splicing. This analysis should provide general insights into the mechanism of alternative trans-splicing, which is expected to play an important role for increasing protein diversity in higher eukaryotes.

• DFG Programme: Research Grants