Fig. 5.

Age-related increase in the levels of methylated CpG1, examined by COBRA, in spermatozoa obtained from a Holstein bull (H1–H5, Fig. 3) and three Japanese Black bulls (JD, JE, and JF). Each lane of the three DNA bands was measured by densitometry and is shown as percentages. ++: 101–112 bp (indicated by a black arrow in Fig. 3A), +: 140–151 bp (indicated by a gray arrow in Fig. 3A), –: 181 bp (indicated by a white arrow in Fig. 3A). Age (months) of bulls at the time of semen collection is indicated below each bull number.