Increased H2AX phosphorylation in the GCs of Dnmt1 hypomorphic mice. (A) The number of phosphoH2AX positive cells per GC was counted in WT or Dnmt1N/⁺ mice at day 10 after immunization with SRBC based on immunofluorescent staining of splenic sections (B) Representative images from the immunofluorescent staining of WT and Dnmt1N/⁺ hypomorphic mice using a nuclear stain (green) and anti-phosphoH2AX monoclonal antibody (red), (top: overlay; middle: anti-phosphoH2AX antibody; and bottom: nuclear stain only).