Characterization ofSpo11-dependent and independent phospho-H2AX foci during meiotic prophase I in the male mouse

• DOI: 10.1242/jcs.004945
• Publication Date: 2007-04-25T02:08:54Z
• Authors: Alexandra Chichep...; Jacqueline Bernar...; Bernard de Massy; Bernard Dutrillaux
• Keywords: Synaptonemal complex; Spermatocyte

Meiotic DNA double strand breaks (DSBs) are indicated at leptotene by the phosphorylated form of histone H2AX (γ-H2AX). In contrast to previous studies, we identified on both zygotene and pachytene chromosomes two distinct types γ-H2AX foci: multiple small (S) foci located along autosomal synaptonemal complexes (SCs) larger signals chromatin loops (L-foci). The S-foci number gradually declined throughout pachytene, in parallel with repair DSBs monitored proteins suggesting that mark DSB events. We validated this interpretation showing absence Spo11–/– spermatocytes. By contrast, L-foci was very low through pachytene. Based analysis labeling after irradiation spermatocytes, formation clearly induced formation. Upon repair, these appear be processed lead above mentioned S-foci. presence wild-type diplotene could therefore reflect delayed or unregulated Interestingly, their distribution different Spo11+/– spermatocytes compared Spo11+/+ where might differently regulated as a response homeostatic control crossing-over. raises interesting possibility yet uncharacterized alterations chromosome structure cells.