embryos

Bits of human brain tissue no larger than a pea are forcing scientists to think about questions as large as the nature of consciousness.

These clusters of living brain cells are popularly known as minibrains, though scientists prefer to call them cerebral organoids. At the moment, they remain extremely rudimentary versions of an actual human brain and are used primarily to study brain development and disorders like autism.

An Ohio fertility clinic said that the remote alarm system on its storage tank was turned off, so it didn't know that the temperature had fluctuated, and that the consequences were worse than it initially thought — all 4,000 eggs and embryos in the cryofreezer are likely nonviable.

A San Francisco fertility clinic says that a problem with the liquid nitrogen in one of its storage tanks may have damaged thousands of frozen eggs and embryos, triggering calls and letters to more than 400 concerned patients of the Pacific Fertility Center.

For the first time, scientists have edited the DNA in human embryos to make a fundamental discovery about the earliest days of human development.

By modifying a key gene in very early-stage embryos, the researchers demonstrated that a gene plays a crucial role in making sure embryos develop normally, the scientists say.

The news that U.S. scientists have successfully cloned a human embryo seems almost certain to rekindle a political fight that has raged, on and off, since the announcement of the creation of Dolly the sheep in 1997.