Resistance of IAPs to methylation reprogramming may provide a mechanism for epigenetic inheritance in the mouse.
Genome-wide epigenetic reprogramming by demethylation occurs in early mouse embryos and primordial germ cells. In early embryos many single-copy sequences become demethylated both by active and passive demethylation, whereas imprinted gene methylation remains unaffected. In primordial germ cells single-copy and imprinted sequences are demethylated, presumably by active demethylation. Here we investigated systematically by bisulphite sequencing the methylation profiles of IAP and Line1 repeated sequence families during preimplantation and primordial germ cell development. Whereas Line1 elements were substantially demethylated during both developmental periods, IAP elements were largely resistant to demethylation, particularly during preimplantation development. This may be desirable in order to prevent IAP retrotransposition, which could cause mutations. In turn, this can result in the transgenerational inheritance of epigenetic states of IAPs, which could lead to heritable epimutations of neighbouring genes through influencing their transcriptional states.
Lane
Natasha
N
Laboratory of Developmental Genetics and Imprinting, The Babraham Institute, Cambridge, UK.
Dean
Wendy
W
Erhardt
Sylvia
S
Hajkova
Petra
P
Surani
Azim
A
Walter
Jörn
J
Reik
Wolf
W
D000483:Alleles; D000818:Animals; D015139:Blotting, Southern; D018899:CpG Islands; D019175:DNA Methylation; D005260:Female; D007426:Genes, Intracisternal A-Particle; D016678:Genome; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008957:Models, Genetic; D013447:Sulfites / Q000494:pharmacology; D013997:Time Factors; D014158:Transcription, Genetic
D013447:Sulfites