Objective: To identify genes differentially expressed in the window of implantation and explore the molecular basis of the development of endometrial receptivity.
Methods: A subtracted cDNA library of the window of implantation was constructed by suppression subtractive hybridization (SSH) method. The screened clones of the subtracted library were sequenced and GenBank homology search was performed. The differential expression of ribosomal protein (RP) L7, RPL7 pseudogene (RPL7p), RPL19 and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta polypeptide (YWHAZ) were further confirmed by RT-PCR.
Results: After sequencing and GenBank homology search of 50 clones, 35 differentially expressed genes were detected in the window of implantation, of which 23 were known genes, and 12 were unknown genes. Some of the known genes have been proved to be associated with implantation, while others were firstly screened out by us. The results of RT-PCR confirmed that RPL7, RPL7p, RPL19 and YWHAZ were highly expressed in the window of implantation, 0.75 +/- 0.21, 1.72 +/- 0.30, 1.23 +/- 0.31, and 1.28 +/- 0.08, respectively.
Conclusions: SSH is a useful technique to detect differential expression genes and an effective method to clone novel genes. It provides a new method to investigate the molecular basis of the development of endometrial receptivity.