Key Step In Muscle-Fiber Formation ID'd

A key step that controls whether immature muscle cells will mature into muscle fibers has been identified by scientists at the University of California-Berkeley. Maria Divina Deato and Robert Tjian, who announced their results online Aug. 17 in Genes & Development, identified two molecules that have to stick to each other and to a specific DNA sequence for myoblasts (immature muscle cells) to fuse with each other and become myotubes (early muscle fibers).

They say proteins known as TRF3 and TAF3 have to stick together and replace another cluster of proteins that would direct the cell along alternative pathways.

The finding may prove useful in the development of treatments involving muscle stem cells.