Methylation status in gametes. (A) Nonparental methylation of CGIs 4 and 5 in sperm. (Top) Schematic structure of CGIs 4 and 5 in and around p57^Kip2 . The bent arrow indicates a transcriptional start site; the open box on the line representsp57^Kip2 . The gray boxes below the line represent CGIs 4 and 5. The methylation status of sperm genomic DNA is presented. (B) Nonparental methylation of CGI10 in sperm. The methylation status of sperm genomic DNA is presented in Tssc4 promoter. (C) Gametic methylation of CGI8 in oocyte but not in sperm. The methylation status of CGIs 8a and 8b is shown in sperm and oocyte. In oocyte, clones are grouped by separate PCRs. The schematic presentation is the same as shown in Fig. 2. However, the first 11 and first 16 CpGs are presented in CGI8a and CGI8b, respectively. These were analyzed by bisulphite sequencing in BPF₁.