Drosophila Hold'em Is Required for a Subset of Meiotic Crossovers and Interacts With the DNA Repair Endonuclease Complex Subunits MEI-9 and ERCC1

Three Drosophila proteins, ERCC1, MUS312, and MEI-9, function in a complex proposed to resolve double-Holliday-junction intermediates into crossovers during meiosis. We report here the characterization of hold'em (hdm), whose protein product belongs to a single-strand-DNA-binding superfamily of proteins. Mutations in hdm result in reduced meiotic crossover formation and sensitivity to the DNA-damaging agent methyl methanesulfonate. Furthermore, HDM physically interacts with both MEI-9 and ERCC1 in a yeast two-hybrid assay. We conclude that HDM, MEI-9, MUS312, and ERCC1 form a complex that resolves meiotic recombination intermediates into crossovers.