Mapping of Crossover Sites Using DNA Microarrays

Crossovers (COs) play an essential role in promoting successful chromosome segregation during meiosis. Crossing over generates chiasmata, which are physical bridges between homologs that provide the appropriate tension to properly align chromosomes on the meiosis I spindle. Homolog pairs that fail to cross over can result in meiosis I nondisjunction, leading to aneuploid gametes. Therefore, the number and distribution of crossovers are tightly regulated to ensure that each chromosome pair receives at least one CO. Here, we describe a DNA microarray-based method to map CO distribution genome-wide, on a cell-by-cell basis, allowing for rapid and accurate analysis of multiple aspects of CO control.