Mammals develop in the uterus of its mother, forming from one cell into trillions. Researchers have found a new method to observe the development of mice embryos without have to cut open the mother's womb. A "glass embryo" was created by using a beaker filled with a nutrient rich solution, an environment identical to a female mouse's uterus. The embryo survived for 11 out of the usual 20 days it takes for the embryo to fully develop.
Although the pup did not survive the entire time, researchers were able to observe the development of multiple systems. This could lead the way to observing development in other organisms. The new method is pretty special and it must be amazing to see the development of a lab-grown embryo.