This sequence of images shows the development of embryos formed after eggs were injected with both CRISPR, a gene-editing tool, and sperm from a donor with a genetic mutation known to cause cardiomyopathy.
Image of a CAR-T cell (reddish) attacking a leukemia cell (green). These CAR-T lymphocytes are used for immunotherapy against cancer (CAR stands for chimeric antigen receptor). After the proliferation of the CAR-expressing T cells, they are transfused back into the patient and can directly detect the cancer cells carrying the antigen.
Eye of Science/Science Source
An 18th-century etching by artist John Kay depicts the extra tall Charles Byrne, the extra short George Cranstoun and three contemporaries of more conventional height. Byrne made his living as a professional spectacle and died at age 22 in 1783.
Wellcome Library, London/Wellcome Images
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
"It would be disingenuous of me not to suggest that the link between the ... recommendations and insurance coverage hasn't put an additional focus on our work," says Dr. Michael LeFevre.
Courtesy of Michael LeFevre
The U.K. could become the first country to legalize the production of a human embryo from three donors. Here, the freezing platform for an embryo, top, also known as a straw, is seen at an in vitro fertilization lab.
Oklahoma Gov. Mary Fallin issues a statement to the media after the execution of Clayton Lockett. Oklahoma Secretary of Safety and Security Michael C. Thompson stands behind her at the Oklahoma State Capitol in Oklahoma City.