DNA methylation reprogramming in human preimplantation development.

  • Laetitia Petrussa ((PhD) Student)

Scriptie/masterproef: Doctoral Thesis


Epigenetic marks such as DNA methylation allow for gene expression
regulation independent of the underlying DNA sequence. During the first
days of embryonic development, there is genome-wide epigenetic
reprogramming that is essential for further development. Studies on human
and various animal models indicate that this epigenetic reprogramming
might be hampered by external and environmental factors such as those
present during assisted reproductive technologies (ART).
Since most of our knowledge on reprogramming in embryos came from
animal studies and species-specific differences in DNA (de)methylation
kinetics had been suggested in literature, there was a need to investigate
DNA methylation reprogramming during human preimplantation
development. We therefore studied global DNA (de)methylation patterns
together with their regulators, the DNA methyltransferases (DNMTs), in
human oocytes, zygotes and embryos up to day 7 of in vitro preimplantation
The data obtained from human good quality fresh embryos served as
reference data in studies of poor quality embryos and in safety studies
investigating the impact of oocyte or embryo cryopreservation on DNA
methylation reprogramming.
Appropriate DNA (hydroxy)methylation reprogramming was linked with good
embryo quality up to the blastocyst stage. Global methylation patterns as
well as DNMT expression patterns were disturbed in thawed embryos. The
data that emerged from our experiments differed compared to the current
model for DNA methylation reprogramming, largely based on mouse data,
calling for an amendment of the model.
Datum Prijs23 mei 2017
Toekennende instantie
  • Vrije Universiteit Brussel
BegeleiderMartine De Rycke (Promotor), Hilde Van De Velde (Promotor), Willem Verpoest (Jury), Ellen Anckaert (Jury), Luc Leyns (Jury), Ingrid Segers (Jury), Esther Baart (Jury) & Ann Van Soom (Jury)

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