Baarends Lab

Department                            Developmental Biology

Principal investigator            Willy Baarends

E-mail address              


Human in vitro oogenesis: bridge technology gaps, improve protocols, enhance knowledge

Supervisor: Ilse de Bruin,

Human oogenesis is hard to study in vivo, because it mostly occurs during the fetal period, bringing both technical and ethical difficulties. That’s why we focus on creating an in vitro differentiation model of human oogenesis to be able to study all aspects of egg cell development. We are culturing immature germ cells and optimizing differentiation protocols for oocyte development, while checking expression levels using qPCR and immunostaining / confocal microscopy. Furthermore, we study X chromosomal dynamics during germ cell specification, which can be analyzed by for example RNA FISH / confocal microscopy. Lastly, we analyze recombinase locations of homolog pairing during meiotic prophase I in human oocytes, using the superresolution microscopy technique dSTORM and analysis in Fiji / R.


  • IPS culture and differentiation,
  • Co-culture systems with mouse primary material
  • RNA extraction and RNA FISH
  • cDNA synthesis
  • qPCR
  • dSTORM and confocal microscopy
  • Data analysis in R
  • Immunofluorescence staining


In vitro differentiation towards the human fetal ovarian soma

Supervisor: Nina Dartée,

Development of reproductive cells (gametes), oocytes in females, relies on the support of somatic granulosa cells (GCs). GCs encapsulate premature oocytes, forming a follicle that enables the progression of oocytes through the first stages of meiosis. We aim to model in vitro gametogenesis by producing the female reproductive by combining hiPSC-derived granulosa-like cells and hiPSC-derived oocytes. My project focusses on differentiating the supporting cells in vitro. To find and understand the signals that guide granulosa cell differentiation, we are analyzing sequencing data and creating reporter cell lines for large scale condition testing. Furthermore, we are testing 2D and 3D cell culture conditions and assessing methylation and transcriptome status of pluripotent and differentiated cells in vitro and in vivo to recapitulate the fetal ovary as accurately as possible.


  • IPS culture and differentiation
  • Co-culture systems with mouse primary material
  • DNA and RNA extraction
  • cDNA synthesis
  • (q)PCR and gel electrophoresis
  • Bacterial work (e.g. transfection)
  • Confocal microscopy
  • Big data analysis (e.g. single cell and bulk RNA sequencing, methylation sequencing) in R