Assessment of 'one-step' versus 'sequential' embryo culture conditions through embryonic genome methylation and hydroxymethylation changes.

Study Question: In comparison to in vivo development, how do different conditions of in vitro culture ('one step' versus 'sequential medium') impact DNA methylation and hydroxymethylation in preimplantation embryos?

Summary Answer: Using rabbit as a model, we show that DNA methylation and hydroxymethylation are both affected by in vitro culture of preimplantation embryos and the effect observed depends on the culture medium used.

What Is Known Already: Correct regulation of DNA methylation is essential for embryonic development and DNA hydroxymethylation appears more and more to be a key player. Modifications of the environment of early embryos are known to have long term effects on adult phenotypes and health; these probably rely on epigenetic alterations.