Transcript analysis identifies differential uterine gene expression profile beyond the normal implantation window in mice

- The receptive state of the uterus is defined as a limited time period when the uterine milieu is favorable for blastocyst implantation.
- It is generally considered as day 4 of pregnancy in mice.
- The uterine status beyond the normal implantation window is unfavorable for implantation and subsequent development.
- Microarray analysis was performed to explore the molecular basis that distinguishes the normal and defective uterine receptivity.
- Approximate 229 genes were differentially expressed, and a large amount were epithelial-expressed and responsive to progesterone signaling.

Uterine receptivity is defined as a state when the uterine milieu is favorable for blastocyst implantation and it can only last for a limited time period. In this study, by utilizing the embryo transfer model, it was observed that a portion of blastocysts could initiate implantation even when transferred beyond the timing of normal uterine receptivity, while their mid-gestational embryo development exhibited severe retardation, suggesting that the uterine status beyond the normal implantation window is unconducive for normal implantation. We further performed microarray analysis to explore the molecular basis that distinguishes the normal and defective uterine receptivity. A total of 229 genes was found to be differentially expressed, and a large amount of them were epithelium-expressing genes and responsive to progesterone signaling.