PathwayStep4766 PathwayStep4764 PathwayStep4765 PathwayStep4761 PathwayStep4763 PathwayStep4762 Recruitment of ATR Kinase to Unsynapsed Regions ATR Phosphorylates Histone H2A.X at Unsynapsed Regions Formation of Axial/Lateral Elements of Synaptonemal Complex Formation of the telomere bouquet Synapsis Recruitment of BRCA1 to Unsynapsed Regions Meiotic Synapsis Authored: May, B, 2011-02-25 Edited: May, B, 2011-02-25 Meiotic synapsis is the stable physical pairing of homologous chromosomes that begins in leptonema of prophase I and lasts until anaphase of prophase I. First, short segments of axial elements form along chromosomes. Telomeres then cluster at a region of the inner nuclear membrane and axial elements extend and fuse along the length of the chromosomes. Subsequent to the initiation of recombination transverse filaments of SYCP1 link axial/lateral elements to a central element containing SYCE1 and SYCE2, thus forming the synaptonemal complex (reviewed in Yang and Wang 2009).<br>Unsynapsed regions are silenced during pachynema by recruitment of BRCA1 and ATR, which phosphorylates histone H2AX (reviewed in Inagaki et al. 2010). Pubmed18948708 Pubmed20364103 Reactome Database ID Release 431221632 Reactome, http://www.reactome.org ReactomeREACT_75792 Reviewed: Bolcun-Filas, E, 2011-02-25 Reviewed: Cohen, PE, 2011-02-04 Reviewed: Holloway, JK, 2011-02-04 Reviewed: Lyndaker, A, 2011-02-25 Reviewed: Schimenti, JC, 2011-02-04 Reviewed: Strong, E, 2011-02-25