Title: Characterizing mei-9 and mus-309 in Drosophila

(Research Advisor: Dr. Jeff Sekelsky, Mentor: Sarah Radford)

Kim Baxter

My work focuses on characterizing the role of the gene mei-9 in fruit flies. It is known that this gene encodes a DNA endonuclease and is part of the nucleotide excision pathway, by which damaged DNA is repaired . We're proposing that mei-9 resolves Holliday junctions - structural intermediates that occur in the process of recombination. I'm trying to rescue defects caused by a mei-9 mutation by inserting into flies a gene from bacteria that is known to resolve Holliday junctions. We also propose that the gene mus-309 facilitates a secondary repair pathway involving the detangling of replication forks during embryonic development. I'm creating a stock of flies with a mutation in mus-309 that contain a fluorescent protein histone - this will allow me to watch real time chromosome dynamics during development to test my hypothesis.