Human preimplantation development starts with the fertilization of an oocyte which results in a totipotent zygote. Following fertilization, the zygote undergoes a number of cleavage divisions leading to compaction on day 4 and blastulation on day 5. Compaction is a process during which the cell-cell contacts increase. The cells also acquire apical/basal polarity. A blastocyst is composed of an outer epithelial layer of cells called the trophectoderm (TE) that encloses a fluid-filled cavity with a clump of undifferentiated cells called the inner cell mass (ICM). These two cell types represent the first differentiation during early human embryogenesis. The TE forms extra-embryonic trophoblast structures and is responsible for implantation. The ICM forms the embryo proper and is the source of human embryonic stem cells (hESCs).
Due to the scarcity of human research materials and the ethical objections regarding the use of human embryos, it remains largely unknown how these lineages are established in the human. In mice, lineage segregation is controlled by specific transcription factors and several models have been described to explain how apparently morphologically identical cells differentiate into these distinct cell types. Moreover, it has recently been demonstrated that different signalling pathways play a key role during this differentiation event.
In this project we aim to analyse transcription factors (NANOG, POU5F1, SOX2 and CDX2) and signalling pathways (WNT, BMP4, Hippo) that contribute to the first lineage differentiation in human embryos. We are also investigating models such as polarisation and the position of the cells during compaction. This study will contribute to our basic knowledge on human embryogenesis and stem cell biology.
Ongoing @ REPRODUCTION AND IMMUNOLOGY
SHARI MACKENS. PhD project: Decidualization and mesenchymal stem cells: assessing endometrial functionality
AN VERLOES. PhD project: HLA-G expression in human embryonic cells
Graduated @ REPRODUCTION AND IMMUNOLOGY
ASMA ABERKANE. Public defence 5 July 2018. PhD dissertation: Early steps of human embryo implantation mimicked in a dish. Promoter: Van de Velde H
Graduated @ REPRODUCTION AND GENETICS
CAROLINE DE PAEPE. Public defence 24 January 2018. PhD dissertation: Totipotency versus differentiation in human embryonic cells. Promoters: Van de Velde H, Geens M
LAETITIA PETRUSSA. Public defence 23 May 2017. PhD dissertation: DNA methylation reprogramming in human preimplantation development. Promoters: De Rijcke M, Van de Velde H
NEELKE DE MUNCK. Public defence 20 December 2016. PhD dissertation: Oocyte vitrification: efficiency and safety in an oocyte donation programme. Promoters: Van de Velde H, Verheyen G, Stoop D
LISBET VAN LANDUYT. Public defence 15 December 2016. PhD dissertation: Vitrification of cleavage stage embryos and blastocysts in ART practice. Promoters: Van de Velde H, Verheyen G
MARIA KRIVEGA. Public defence 3 September 2015. PhD dissertation: Balancing between totipotency and differentiation in human embryos. Promoter: Van de Velde H, Co-promoter: Mieke Geens
MIEKE GEENS. Public defence 27 May 2010. PhD dissertation: Strategies for fertility preservation and restoration in the male. Promoter: Tournaye H, Co-promoter: Van de Velde
GREET CAUFFMAN. Public defence 12 May 2009. PhD dissertation: Gene expression and cell commitment in the human preimplantation embyro. Promoter: Liebaers I, Co-promoter: Van de Velde H
Research output : Contribution to journal...
Random Mutagenesis, Clonal Events, and Embryonic or Somatic Origin Determine the mtDNA Variant Type and Load in Human Pluripotent Stem Cells
In-cycle prediction of the outcome after fresh embryo transfer in IVF/ICSI: a molecular analysis of follicular endometrial biopsies