[Heather Jameson (OP)]

Jon asked:

I heard about using stem cells to cure heart disease, which got me to wonder exactly how a cell knows what kind of cell it is.  That is, the genome is available to create a variety of proteins, and some pattern of enabling occurs for each type of cell, but where is the identity of the cell stored?  How does a cell know it is a muscle cell vs a skin cell?

Can you help?

[evan_au]

The identity of a cell is stored in epigenetic markers.

As cells specialise in the embryo, epigenetic markers are added to indicate what part of the body it is, and that directs further specialisation into individual tissues, with more specific epigenetic markers.

See: https://en.wikipedia.org/wiki/Epigenetics#Development

[Iluminatis]

Hey thank you for sharing