The study investigates the dynamics of genome-wide DNA methylation reprogramming in mouse primordial germ cells (PGCs). It presents data on global methylation profiling, promoters with slow demethylating kinetics, resistance to demethylation, and the local effect of IAPs on methylation resistance. The research also explores resistant CGIs in various datasets, hairpin phasing analysis of the LINE1Tf consensus sequence, passive demethylation pathways, and correlations between transcription and DNA methylation. The study includes detailed experimental procedures for DNA/RNA purification, annotations, BS-Seq and RNA-Seq analyses, and functional enrichment analysis. The findings reveal that methylation levels change dynamically during PGC development, with certain regions showing resistance to demethylation. IAPs are associated with increased methylation resistance, and the study highlights the role of DNA methylation in gene regulation and development. The research provides insights into the mechanisms underlying DNA methylation reprogramming in PGCs and its implications for germline development and epigenetic inheritance. The study is supported by a range of datasets and references to previous research on DNA methylation and gene regulation.The study investigates the dynamics of genome-wide DNA methylation reprogramming in mouse primordial germ cells (PGCs). It presents data on global methylation profiling, promoters with slow demethylating kinetics, resistance to demethylation, and the local effect of IAPs on methylation resistance. The research also explores resistant CGIs in various datasets, hairpin phasing analysis of the LINE1Tf consensus sequence, passive demethylation pathways, and correlations between transcription and DNA methylation. The study includes detailed experimental procedures for DNA/RNA purification, annotations, BS-Seq and RNA-Seq analyses, and functional enrichment analysis. The findings reveal that methylation levels change dynamically during PGC development, with certain regions showing resistance to demethylation. IAPs are associated with increased methylation resistance, and the study highlights the role of DNA methylation in gene regulation and development. The research provides insights into the mechanisms underlying DNA methylation reprogramming in PGCs and its implications for germline development and epigenetic inheritance. The study is supported by a range of datasets and references to previous research on DNA methylation and gene regulation.