For the first time, scientists have created mouse embryos in the lab without using any eggs or sperm and watched them grow outside the womb. To achieve this feat, the researchers used only stem cells and a spinning device filled with shiny glass vials.
The experiment is a “game changer,” Alfonso Martinez Arias, a developmental biologist at Pompeu Fabra University in Barcelona who was not involved in the research, told The Washington Post(opens in new tab).
“This is an important landmark in our understanding of how embryos build themselves,” he said.
The breakthrough experiment, described in a report published Monday (Aug. 1) in the journal Cell(opens in new tab), took place in a specially designed bioreactor that serves as an artificial womb for developing embryos. Within the device, embryos float in small beakers of nutrient-filled solution, and the beakers are all locked into a spinning cylinder that keeps them in constant motion. This movement simulates how blood and nutrients flow to the placenta. The device also replicates the atmospheric pressure of a mouse uterus, according to a statement(opens in new tab) from the Weizmann Institute of Science in Israel, where the research was conducted.
In a previous experiment, described in the journal Nature(opens in new tab) in 2021, the team used this bioreactor to grow natural mouse embryos, which reached day 11 of development in the device. “That really showed that mammalian embryos can grow outside the uterus — it’s not really patterning or sending signals to the embryo so much as providing nutritional support,” Jacob Hanna, an embryonic stem cell biologist at the Weizmann and senior author of both studies, told STAT News