Scientists Report Creating Human Sperm from Stem Cells

Time Magazine: Scientists Create Human Sperm from Stem Cells, by Alice Park:

Researchers at Newcastle University in England report they have coaxed the first human sperm cells from embryonic stem cells, in a remarkable demonstration of how quickly the field of stem-cell science is moving.

The achievement, described in the journal Stem Cells and Development, comes just 11 years after the first human-embryonic-stem-cell line was created — an eyeblink in scientific terms — in the lab of James Thomson at the University of Wisconsin. (See the top 10 scientific discoveries of 2008.)

Although the development once again raises the specter of creating humans in a petri dish or custom-designing egg and sperm cells for reproduction, lead author Karim Nayernia says that was not his team's intention. Rather, the experiment was a proof of concept that stem cells can generate any cell in the body — not only the dozens of tissues that make up the human body but also those egg and sperm cells that may give rise to altogether new bodies.