Figure 5.

H1 restricts the assembly of prereplication complexes on sperm chromatin. Xenopus sperm chromatin was incubated at 1 ng DNA/μl in extract containing biotinylated dUTP and H1 (H1) or without H1 (Control) for up to 90 min. After 15, 30, 45, and 90 min in extract, the samples were processed as described in MATERIALS AND METHODS. XOrc2 (A), XCdc6 (B), and XMcm3 (C) were visualized by indirect immunofluorescence, and biotin incorporation was detected with fluorescent streptavidin (C). Samples were examined by confocal microscopy.