This study establishes an important role for the enzyme Tet1 in erasing genomic imprinting in vivo — mice with a knockout of paternal Tet1 give rise to progeny with imprinting defects and associated growth and development defects, which leads to early embryonic lethality; furthermore, analysis of the DNA methylation dynamics in reprogramming primordial germ cells (PGCs) suggests that Tet1 is required at a late stage of the reprogramming process, in the second wave of DNA demethylation in PGCs.
- Shinpei Yamaguchi
- Li Shen
- Yi Zhang
