Expression of the novel gene embryo implantation factor 2 (EMO2) in the mouse uterus at the implantation sites.

OBJECTIVE

The aim of this study was to identify a novel implantation-related molecule and to examine EMO2 expression in the mouse uterus during the peri-implantation period.

DESIGN

Experimental study.

SETTING

Research laboratory.

ANIMAL(S): Adult ICR mice aged 6-8 weeks.

INTERVENTION(S): Adult female mice were mated with fertile males to achieve pregnancy. Implantation was delayed by ovariectomizing pregnant mice on day 4 and administering P during days 5-7; implantation was then initiated by administering E(2). Pseudopregnant mice were obtained by mating females with vasectomized males.

MAIN OUTCOME MEASURE(S): The tissue distribution of EMO2 mRNA was detected by reverse transcriptase-polymerase chain reaction, and the uterine expression pattern of the EMO2 protein was determined by immunohistochemistry.

RESULT(S): The full cDNA sequence of EMO2 was registered in GenBank (AY372183). EMO2 mRNA expression was observed in all mouse tissues tested. The expression of the EMO2 protein was predominately localized in decidual cells at the implantation site during days 5-6 of pregnancy, and its expression was induced by the active blastocyst and artificially induced decidualization.

CONCLUSION(S): Our data indicate that EMO2 may play a key role in the mouse embryo implantation process.