1. Ghent-Fertility and Stem Cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium.
2. Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, the Netherlands.
3. Laboratory of Pharmaceutical Biotechnology, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.
4. Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.
5. Technology and Development Team for Mammalian Genome Dynamics, RIKEN BioResource Center, Tsukuba, Japan.