Objective: To find valuable implantation-related genes associated with endometrial receptivity by scanning the complete genome array of endometrium at the luteal phase of superovulation cycle and the natural cycle.
Methods: Twenty endometrial samples were obtained from patients who were to undergo invitro fertilization and embryo transfer because of the ovarian or male factors, underwent real-time quantitative PCR (QPCR) to confirm the differentially expressed genes and pathological examination to confirm the stages. Five of the 20 endometrial samples from days of LH + 4, LH + 7, or HCG + 7 underwent HU133 plus2.0 microarray scanning. The other 15 samples were divided into 2 groups: 7 samples were taken on the day LH + 7, and 8 samples taken on the day HCG + 7.
Results: 581 genes were expressed differentially in the LH + 7 and LH + 4 samples: 395 were up-regulated and 186 were down-regulated. 320 genes were expressed differentially in the HCG + 7 and LH + 7 samples: 175 genes were up-regulated, and 145 genes were down-regulated. QPCR test showed that the expression levels of some up-regulated genes were much lower on the day HCG + 7 than on the day LH + 7, such as PAEP, S100P, SOD and GDF15.
Conclusion: Microarray scanning provides a global gene expression spectrum of human endometrium at different phases. A set of genes are active at the implantation window phase of endometrium. These genes don't show adequate expression after superovulation, which may lead to the change of endometrial receptivity.