Supplementary dataset 1. Related to fertility assays in Figure 1I and 1J. WT mating male mice were monthly rotated between cages according to this random allocation table. Dates are presumptive. Supplementary dataset 2. Related to figure 7A-C. This excel file contains FPKM values of three WT or Gm364-KO repeats, Log2-Ave value, and Log2(Ave-Gm364-KO/ave-WT) for each genes. To avoid the illegal calculation of value “0”, we added a minimal value “0.001” to all original values (we have verified that this did not alter any differential trends). The data were arranged to the ascending order of Log 2(Ave-Gm364-KO/ave-WT) values. Supplementary dataset 3. Related to figure 7D and 7E. This excel file contains six sheets. "CPG-all info", "CHG-all info", and "CHH-all info" contain all original information for CPG, CHG, or CHH promoter regions of each genes; "CpG methyl value", "CHG methyl value", and "CHH methyl value" contain methylation values, Ave methylation values of three WT or Gm364-KO repeats, Log2-Ave value, and Log2(Ave-Gm364-KO/ave-WT) for CPG, CHG, or CHH promoter regions of each genes. To avoid the illegal calculation of value “0”, we added a minimal value “0.001” to all original values (we have verified that this did not alter any differential trends). The data were arranged to the ascending order of Log 2(Ave-Gm364-KO/ave-WT) values. Supplementary dataset 4. Related to figure 8A and 8G. This excel file contains two sheets. "RNA seq up & down top 20" contains top 20 up-regulated & down-regulated DEGs; "RRBS up & down top 20" contains top 20 up-regulated & down-regulated DMRs.