Unsynapsed regions of chromosomes are silenced during pachytene phase by a process called Meiotic Silencing of Unsynapsed Chromatin (MSUC) and, in the case of the X and Y chromosomes, Meiotic Sex Chromosome Inactivation (MSCI). Unsynapsed meiotic chromatin recruits BRCA1 (Scully et al. 1997, Garcia-Cruz et al. 2009). In mouse, the recruitment requires SYCP3 of axial elements of the synaptonemal complex, which may remain exposed in unsynapsed regions.
Garcia Caldés, M