The long-range objectives of our research are to understand the mechanism of meiotic recombination and to determine how this process is coordinated with other events of meiotic prophase. We focus much of our attention on Spo11 (the protein that makes the DNA double-stand breaks (DSBs) that initiate recombination), the proteins that interact with Spo11, and the interactions of these proteins with meiotic chromosomes. We are also examining the mechanisms that regulate the timing, number, and location of DSB formation. Our studies of Spo11 have also provided an entry point to research on the DSBs made by the enzyme Topoisomerase II when it is inhibited by chemotherapeutic agents such as etoposide or doxorubicin.