DNA double strand break repair, chromosome synapsis and transcriptional silencing in meiosis.

Chromosome pairing and synapsis during meiotic prophase requires the formation and repair of DNA double-strand breaks (DSBs) by the topoisomerase-like enzyme SPO11. Chromosomes, or chromosomal regions, that lack a pairing partner, such as the largely heterologous X and Y chromosomes, show delayed meiotic DSB repair and are transcriptionally silenced. Herein, we review meiosis-specific aspects of DSB repair in relation to homology recognition and meiotic silencing of heterologous regions. We propose a dynamic interplay between progression of synapsis and persistent meiotic DSBs. Signaling from these persistent breaks could inhibit heterologous synapsis and stimulate meiotic silencing of the X and Y chromosomes.