Ndj1, a Telomere-Associated Protein, Promotes Meiotic Recombination in Budding Yeast

Abstract

Dynamic telomere repositioning is a prominent feature of meiosis. Deletion of a telomere-associated protein, Ndj1, results in the failure of both attachment and clustering of telomeres at the nuclear envelope and delays several landmarks of meiosis I, such as pairing, synaptonemal complex formation, and timing of the meiosis I division. We explored the role of Ndj1 in meiotic recombination, which occurs through the formation and repair of programmed double-strand breaks. The ndj1Δ mutation allows for the formation of the first detectable strand invasion intermediate (i.e., single-end invasion) with wild-type kinetics; however, it confers a delay in the formation of the double-Holliday junction intermediate and both crossover and noncrossover products. These results challenge the widely held notion that clustering of telomeres in meiosis promotes the ability of homologous chromosomes to find one another in budding Saccharomyces cerevisiae. We propose that an Ndj1-dependent function is critical for stabilizing analogous strand invasion intermediates that exist in two separate branches of the bifurcated pathway, leading to either noncrossover or crossover formation. These findings provide a link between telomere dynamics and a distinct mechanistic step of meiotic recombination that follows the homology search.

We thank Burgess Lab members, Elizabeth Blackburn, JoAnne Engebrecht, Neil Hunter, Nancy Kleckner, Scott Keeney, and Michael Lichten, for discussion. We especially thank Neil Hunter for strains and advice on protocols. We thank JoAnne Engebrecht, Joshua Chang Mell, and Scott Keeney for critical reading of the manuscript.

This work was supported by the American Cancer Society RSG-01-053-01-CCG award to S.M.B.

There are no conflicts of interest.