View Program - 63rd Annual Drosophila Research Conference

During meiosis, recombination between homologous chromosomes ensures genetic diversity among haploid products, but errors in this mechanism are a major source of human infertility. Recombination events, initiated by enzymatic-directed double-stranded breaks can result in crossovers (COs), involving reciprocal exchanges between homologues, or noncrossovers (NCOs), where a portion of DNA is copied from the donor homologue without altering it. Protein complexes known as recombination nodules are thought to reside around future crossovers and promote and catalyze recombination events. Although their function has been hypothesized, its protein composition has not been elucidated, nor has the mechanism through which it facilitates recombination outcomes. Additionally, due to their insoluble nature, previous attempts at isolating recombination nodules using classical biochemical purification techniques have failed. To address these issues, I will generate several fly lines containing proximity biotin-labeling protein, APEX2, conjugates of known recombination proteins. Using these fly lines and mass spectrometry, we will be able to identify novel protein interactors and create interaction maps to elucidate the proteome that is necessary for processing recombination. Utilizing our model system, I eliminate the need to isolate recombination nodules and, instead, can reliably identify protein components and interactions to understand the mechanisms that facilitate meiotic recombination. The protein-protein interactions uncovered will also provide insight into the complex regulatory mechanisms that are required to initiate double-stranded breaks and subsequently repair them as NCOs or COs.

Identification of Meiotic Recombination Nodule Proteins Utilizing Proximity Labeling