Posted on 08/20/2006 1:02:58 AM PDT by neverdem
The human body may seem to change little over the years, but beneath this deceptive calm, cells are in constant flux as old ones are discarded and new ones appear. How do the new recruits know where they are meant to go?
Biologists at Stanford University say they have discovered a coordinate system in human cells that defines their position in the body. This seems to be the first time a cell-based positioning system has been reported for the adult body of any animal, though positioning systems that guide cells in embryogenesis are well known.
The coordinate system, if confirmed, may shed light on processes like wound healing and lend some hope to the prospect of regenerating human tissues from mature cells, as happens in animals like newts and salamanders, rather than from stem cells, the goal of cell therapy.
The Stanford team, led by Howard Chang and John L. Rinn, focused on fibroblasts, a type of cell that is the mainstay of the deep skin and the surfaces that cover the inner organs. Believing that not all fibroblasts are alike, though they may look alike, the team analyzed which genes were turned on or off in fibroblasts sampled from many body sites.
They detected different subsets of genes that were active in fibroblasts from different sites, suggesting that each cell was getting three pieces of information that together would specify a location, the team reports in the current issue of the journal Public Library of Science Genetics.
In this coordinate system, the Stanford researchers propose, one bit of information tells a cell whether it is meant to be part of the body’s inner or outer surfaces. A second directs it to the body’s top or bottom half. A third specifies whether it is at the near or far point...
(Excerpt) Read more at nytimes.com ...
Anatomic Demarcation by Positional Variation in Fibroblast Gene Expression Programs
That's it! Now we finally know why some people are thinking with their derrieres - their cells got misdirected. Maybe it would even become possible to correct.
Wally had his feet up on the desk and his eyes were closed.
The Pointy-Haired Boss walked over and asked him what he was doing.
Wally said, "I may not appear to be doing much, but at the cellular level, I'm actually quite busy."
Oh yeah, this is a much needed clue to life complexity ... appreciate the post.
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