Stem Cells

Researchers Get Closer to Making Functional Human Sperm in the Lab

Stanford researchers found that simply by producing stem cells from adult male skin cells and putting them in the sperm-making tubes of mice, they could obtain partly developed germ cells, the cells that produce sperm. The researchers hypothesized that if the cells had been placed in human testes, with their distinct and roomier topography, they would likely have resulted in functional sperm.

Aging Reversed in the Heart, Brain, and Muscles of Mice Thanks to Blood Factor

The idea that blood is the basic stuff of life dates back to well before the scientific method. Yet, in a pair of new studies, researchers have found that blood — and specifically a growth factor in it known as GDF-11 — spurs the brains, muscles, skeletons and hearts of older mice to look and perform like those of younger mice.