This is an interesting article. This shows that mesenchymal stem cells make both muscle and skeleton during development. Presumably adult mesenchymal stem cells may retain this ability. Wise.

http://www.medicalnewstoday.com/medi...p?newsid=27800

Scientists discover stem cell origin of neck and shoulders

22 Jul 2005

Research published in Nature tomorrow (21 July) will outline for the first time the stem cell origin of the structure of the neck and shoulders in vertebrates. The scientists believe that instead of groups of stem cells creating the skeletal and muscle structure separately they actually appear to make them together as a sort of 'composite'. This could have significant implications for clinical medicine and our understanding of vertebrate evolution.

Scientists at the Wolfson Institute for Biomedical Research of University College London, part-funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and working with international collaborators, used a new genetic technique to tag embryonic stem cells and then trace them to the adult animal. They discovered that instead of homogeneous groups of stem cells making up the bones of the shoulder and neck and another making the muscles, a newly-discovered group of stem cells called mesenchymal stem cells make both the muscles and the point where it joins the skeleton.

The researchers believe their results show that the skeleton and muscles of vertebrates should not be seen as separate but instead are composites, with the boundaries between cell groups blurred around the body. For example, the stem cell group that makes the connective tissues of the swallowing/gulping muscles also makes the skeletal regions of the shoulder girdle. This sheds new light on human diseases such as Klippel-Feil syndrome where both regions are often malformed.