Differential DNA methylation reprogramming of various repetitive sequences in mouse preimplantation embryos.
Genome-wide changes of DNA methylation by active and passive demethylation processes are typical features during preimplantation development. Here we provide an insight that epigenetic reprogramming of DNA methylation is regulated in a region-specific manner, not a genome-wide fashion. To address this hypothesis, methylation states of three repetitive genomic regions were monitored at various developmental stages in the mouse embryos. Active demethylation was not observed in the IAP sequences whereas methylation reprogramming of the satellite sequences was regulated only by the active mechanism. Etn elements were actively demethylated after fertilization, passively demethylated by the 8-cell stage, and de novo methylated at the morular and blastocyst stages, showing dynamic epigenetic changes. Thus, our findings suggest that the specific genomic regions or sequences may spatially/temporally have their unique characteristics in the reprogramming of the DNA methylation during preimplantation development.
Kim
Seok-Ho
SH
Laboratory of Development and Differentiation, Korea Research Institute of Bioscience and Biotechnology (KRIBB), P.O. Box 115, Yuseong, Daejeon 305-600, Republic of Korea.
Kang
Yong-Kook
YK
Koo
Deog-Bon
DB
Kang
Man-Jong
MJ
Moon
Seung-Ju
SJ
Lee
Kyung-Kwang
KK
Han
Yong-Mahn
YM
D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009865:Oocytes / Q000502:physiology; D011247:Pregnancy; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D013094:Spermatozoa / Q000502:physiology