Gene expression in human oocytes and preimplantation embryos

Global gene activation occurs at the 4 to 8 cell stage in human embryos. Prior to this, the initial stages of cleavage divisions are dependent on proteins accumulated in the oocytes during oogenesis. Appropriate gene expression is vital for the regulation of metabolic pathways and key developmental events. Examination of both global and specific gene expression enablesus to investigate the process of normal human preimplantationdevelopment. This is also of clinical significance, becauseof the possibility of identifying embryos that are viable for IVF-embryotransfer.


  1. The main objective of this project is to investigate whether the gene expression pattern of certain genes may be used as predictive indicator to guide the selection of healthy oocytes and embryos with the potential for implantation.
  2. The candidate genes known to play critical roles in early embryo development such as cytokines and growth factors, proteases and protease inhibitors, cell survival and also genes involved in apoptosis and hypoxia in the follicle will be investigated.


Donated unfertilized human oocytes and spare embryos following IVF/PGD treatment will be used for this project. Initially, well established techniques such as Quantitative RT-PCR and immunofluorescence assays will be performed to detect the presence of specific gene expression in preimplantation embryos. The second phase of the study will be to develop reliable microarray techniques to detect gene transcripts at the single cell level.

Principal Investigator: Asangla Ao, PhD  profile
Other researchers: Li Zhang, PhD; Xaio Yun Zhang, MSc; Ahmet Yilmaz, PhD