In these two two-cell mouse embryos, the surface of the embryos is outlined in orange, the DNA in the nucleus is indicated in blue and the activity of the LINE-1 gene is indicated via bright red spots.
Kathy Niakan, a developmental biologist at the Francis Crick Institute in London, used the CRISPR gene editing technique to find out how a gene affects the growth of human embryos.
Courtesy of The Francis Crick Institute
The genes in mitochondria, which are the powerhouses in human cells, can cause fatal inherited disease. But replacing the bad genes may cause other health problems.
Getty Images/Science Photo Library
In 2010, scientists plopped the genetic material of one Mycoplasma bacterium into another type to create the self-replicating cells shown above. Six years later, they've come out with an even simpler synthetic organism that has fewer genes.
Thomas Deerinck, NCMIR/Science Source