Scientists have been aware of two types of pluripotent stem cells. However, Juan Carlos Izpisua Belmonte, a developmental biologist at the Salk Institute for Biological Studies in La Jolla, California, and his team discovered a third type of stem cell, which they have named region-selective pluripotent stem cells (rsPSCs). While attempting to graft human stem cells into mouse embryos, they found that a particular type of PSC was easier to grow than the others when injected into a specific part of the embryo. Interestingly, the researchers found that rsPSCs were easier to edit using DNA-cutting enzymes than other PSCs. Belmonte and his team believes that these newly discovered cells could be used to develop human organs in animals for research. However, the anatomical and ethical constraints could make it difficult to create human-animal hybrids.
Read more in Nature.