WASHINGTON (AP) — For the first time, scientists have used human cells to make structures that mimic the earliest stages of fetal development. The work potentially opens up new avenues for research — and new ethical questions. Two papers published Wednesday in the journal Nature detail how two teams of scientists independently made such structures. They stressed that the work is only for research, not reproduction. The two teams used different methods of making balls of cells that resemble one of the earliest stages of human development. These balls form a few days after an egg has been fertilized but before the cells become an embryo.
Pre-embryos made in lab could spur research, ethics debates
