With improved resolution, tissue-specific molecular markers and precise timing, University of Oregon biologist James A. Weston and colleagues have possibly overturned a long-standing assumption about the origin of embryonic cells that give rise to connective and skeletal tissues that form the base of the skull and facial structures in back-boned creatures from fish to humans.

Researchers have uncovered how embryonic livers accumulate an important energy molecule even though they lacks the key enzyme responsible.

When researchers at Cornell, the University of Bonn and the University of Pittsburgh transplanted living embryonic heart cells into cardiac tissue of mice that had suffered heart attacks, the mice became resistant to cardiac arrhythmias, thereby avoiding one of the most dangerous and fatal consequences of heart attacks.

Muscle fibers are large cells that contain many nuclei. They begin, like all animal cells, as naive embryonic cells. These cells differentiate, producing intermediate cells called myoblasts that are now destined to become muscle. New myoblasts then seek out other myoblasts, and when they find each other, they stick together like best friends.