The experimental mice were then used to observe the relationships of the hormones and their receptors with the protein under varying conditions during the critical implantation period. In doing so, researchers determined that C/EBPb is a critical mediator of steroid hormone responsiveness in the uterus.
"This gene is expressed when the uterus is ready for embryo attachment," said co-author Indrani C. Bagchi, a professor of veterinary biosciences in the College of Veterinary Medicine at Illinois. "Its presence indicates a window for success."
If the findings are replicated in human tissue, as expected, she said, the protein's presence could become a vital gene marker for predicting uterine readiness for pregnancy.
"The success rate for the practice of in vitro fertilization currently is, on average, about 25 percent," she said. "The major problem is that the conditions occurring when the embryo is transferred often are not the best in the uterus. It's not known if the uterus is ready to accept an embryo, so often multiple embryos are transferred in hopes that one will attach. In future studies, confirmation of C/EBPb as a marker that correctly indicates uterine readiness for implantation in the human is likely to alleviate these shortcomings."
Other co-authors of the paper were doctoral student Srinivasa Raju Mantena, postdoctoral researchers Athilakshmi Kannan and Yong-Pil Cheon, and research scientist Quanxi Li, all in Indrani Bagchi's veterinary biosciences laboratory.