Stem cells have the ability to transform into many different types of cells during the body's early development, embryonic stem cell research offers unique insights into how an organism grows from a single cell. For the first time, scientists have now been able to create a mouse embryo entirely artificially. Researchers have modeled a mouse embryo, here shown at 72 hours, using exclusively stem cells. Stem cells are crucial for the development of living organisms.

At the very beginnings of an embryo, these cells will form the entire organism, including the cells that form the body's vital organs and tissues, such as the heart, lungs, and skin. During its first 3 to 5 days, the human or mammalian embryo is called a blastocyst. The blastocyst is made up of embryonic stem cells (ESCs) that are generated by the egg after it has been fertilized by a sperm. The blastocyst also contains…