DNA methylation at CG sites is important for gene regulation and embryonic development. In mouse oocytes. de novo CG methylation requires preceding transcription-coupled histone mark H3K36me3 and is mediated by a DNA methyltransferase DNMT3A. DNMT3A has a PWWP domain. https://www.roneverhart.com/Traditional-Karate-Do-Okinawa-Goju-Ryu-Book-1-The-Fundamental-Techniques-by-Morio-Higaonna-Preowned/