Magic embryology: how stem cells follow genetic instructions (Introduction)

by David Turell , Friday, November 08, 2019, 19:36 (1842 days ago) @ David Turell

It is all automatic:

https://www.sciencedaily.com/releases/2019/11/191107122638.htm

"All cells in the body contain the same genetic material. The difference between cells therefore depends solely on which genes are expressed or 'turned on'. Now, researchers have gained new insights into how genes are turned on and off and how the cells ''forget their past'' while developing into a specific cell in the body. This new knowledge will be crucial for stem cell therapy and potentially treating people with cancer.

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"'We previously thought that transcription factors drive the process that determines whether a gene is expressed and subsequently translated into the corresponding protein. Our new results show that transcription factors may be more analogous to being the memory of the cell. As long as the transcription factors are connected to a gene, the gene can be read (turned on), but the external signals received by the cells seem to determine whether the gene is turned on or off. As soon as the transcription factors are gone, the cells can no longer return to their point of origin," explains Josh Brickman, Professor and Group Leader, DanStem, University of Copenhagen.

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"The researchers developed a stem cell model to mimic a cell's response to signaling and used it to, for first time, precisely determine the sequence of the events involved in a gene being turned on and off in response to a signal in stem cells. The researchers were able to describe how genes are turned on and off and under what circumstances a cell can develop in a certain direction but then elect to return to the starting-point.

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"'Transcription factors are still a key signal, but they do not drive the process, as previously thought. Once they are there, the gene can be read, and they remain in place for a while after the gene is read. And when they are gone, the window in which the gene can be read can be closed again. You can compare it with the vapour trails you see in the sky when an airplane has passed. They linger for a while but slowly dissipate again," explains first author, William Hamilton, Assistant Professor at DanStem."

Comment: All an automatic process, which is the way cells work