Fig. 2.

DNA damage analysis using gamma-H2Ax assay. (a, b) Gamma-H2Ax assay using a zygote fertilized with freeze-dried sperm preserved for one day with or without trehalose. Images show male and female pronuclei stained with 4′6-diamidino-2-phenylindole in blue (upper left), female pronuclei labeled with anti-H3K9 me2 antibody in green (upper right), gamma-H2Ax signals indicating double-stranded DNA breaks in red (lower left), and merged images (lower right). (c, d) The brightness of each male pronucleus derived from FD sperm preserved for 1 day (c) and 3 months (d) was plotted. Circle dots indicate no trehalose treatment, whereas square dots indicate trehalose treatment.