Mechanisms of germ line genome instability.

During meiosis, numerous DNA double-strand breaks (DSBs) are formed as part of the normal developmental program. This seemingly destructive behavior is necessary for successful meiosis, since repair of the DSBs through homologous recombination (HR) helps to produce physical links between the homologous chromosomes essential for correct chromosome segregation later in meiosis. However, DSB formation at such a massive scale also introduces opportunities to generate gross chromosomal rearrangements. In this review, we explore ways in which meiotic DSBs can result in such genomic alterations.