Embryo development starts when a single egg cell is fertilized and starts dividing continuously. Initially a chaotic cluster, it gradually evolves into a highly organized structure. Scientists have ...

Shelby is an assistant editor for The Scientist. She earned her PhD from West Virginia University in immunology and microbiology and completed an AAAS Mass Media fellowship. View full profile. Learn ...

During embryonic stem cell (ESC) development, pluripotent stem cells transition from a naïve state into a primed state before they take their first steps toward a lineage commitment. Jacob Hanna, a ...

A discovery upends decades of assumptions regarding DNA replication. The study show that DNA replication in early embryos is different from what past research has taught, and includes a period of ...

President Bush, saying he wanted to “proceed with great care,” announced in a national address on August 9 that he would allow federal funding of an existing 60 stem-cell lines but would not permit ...

Stem cells from adults and embryos both show enormous promise for treating an array of diseases but at this early stage, cells from days-old embryos appear to offer certain key advantages, according ...