Fig. 8.
H2AX is associated with DSB of ENs and transcriptional silencing. (A)
H2AX domains (red) are associated with the foci (yellow) before synapsis and, when the cores synapse to form an SC (green), the
H2AX domains are minimal, which is possibly an indication that DSBs are no longer detectable. (B) At pachytene, histone H2AX of the X-Y sex chromatin is transcriptionally silenced by phosphorylation (FITC, green). As well, there are autosomal
H2AX domains (FITC, green) that do not appear to be associated with TNs (red foci) and may represent transcriptional silencing of autosomal loci. (C)
H2AX chromatin modification of the sex body and laggards (L). A further indication that pachytene chromatin modification (yellow) may be unrelated to DSBs. Typically, cores (red) that fail to synapse (laggards, L), acquire
H2AX domains in association with ATR and TOPBP1 on the unpaired cores. (D) In prematurely separated lateral elements (green) caused by okadaic acid treatment, some of the
H2AX domains (yellow) are paired (matched arrows), suggesting silencing of autosomal sites.