Stem cells from embryo created without sperm:

“US scientists have isolated stem cells from monkey embryos created using only an egg. They then coaxed these stem cells into taking on the characteristics of neurons, heart muscle and other tissue types.

The embryos were generated through a process called parthenogenesis, in which the egg is never fertilized, but instead duplicates one set of chromosomes. That duplication is lethal, because two maternal sets of chromosomes are incompatible. But the so-called “parthenote” that results still develops far enough so that the equivalent of embryonic stem cells can be harvested from it.” New Scientist