Morgan Koepke Axon Path-finding in the Central Nervous System of Drosophila melanogaster: Determining Enhancers of the trio Mutant Phenotype from a Random Mutational Screen Division Sciences Department Biology Year 2004 Advisor Eric Liebl

The development of the central nervous system (CNS) through a process known as axon pathfinding involves the correlation of several biochemical signaling pathways.  Elucidation of pathway components can be performed through the use of second-site mutagenesis, creating random mutations to genes in a background already containing a known mutation and looking for enhanced or suppressed phenotypes indicative of an interaction.  The role of Trio, a guanine nucleotide exchange factor which interacts with GTPases during axonogenesis in Drosophila, is still being uncovered.  In this study, a preliminary genetic screen for enhancement was performed on trio mutant background Drosophila which had undergone second-site mutagenesis through exposure to gamma-ray radiation.  Three of the stocks were found to be new alleles of previously characterized trio enhancers.  Initial phenotypic observation does indicate at least two potentially novel enhancers of the trio mutant phenotype which are worthy of further investigation.