Stem cell scientists are continuing to turn up new information on how embryonic (and other) stem cells work. Embryonic stem cells are pluripotent, meaning they can transform into any other cell type. But what determines when and how this happens? The latest research reveals one particular process, probably out of many.
The FOXP1 gene codes for a transcription factor that regulates the expression of other genes important in embryonic development. As it turns out, very slightly different proteins can be produced from FOXP1, depending on a process, alternative splicing, that affects the derived messenger RNA. In one form of the final transcription factor, genes that maintain pluripotency are expressed: OCT4, NANOG, NR5A2, and GDF3. But in the alternative form, genes are expressed that cause the cell to differentiate into a non-pluripotent cell. The question remains as to what causes splicing to take one path or the other.
Scientists have found a control switch that regulates stem cell “pluripotency,” the capacity of stem cells to develop into any type of cell in the human body. The discovery reveals that pluripotency is regulated by a single event in a process called alternative splicing.
Alternative splicing allows one gene to generate many different genetic messages and protein products. The researchers found that in genetic messages of a gene called FOXP1, the switch was active in embryonic stem cells but silent in “adult” cells—those that had become the specialized cells that comprise organs and perform functions.