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| image credit: discoveringsomethingnewtoday.blogspot.com |
We all start out as a clump of identical cells. As these cells divide and multiply, they gradually take on distinct identities, acquiring the traits necessary to form, for instance, muscle tissue, bone, or nerves. A recent study from Rockefeller scientists offers new insight into how these cellular identities are cultivated over the course of development.
According to the study, published in eLife, cells retain a memory of the chemical signals to which they are exposed. And, the researchers show, embryos that fail to form these memories remain a clump of clones, never realizing their unique biological potential.
According to the study, published in eLife, cells retain a memory of the chemical signals to which they are exposed. And, the researchers show, embryos that fail to form these memories remain a clump of clones, never realizing their unique biological potential.
Activating embryos
Over 25 years ago, Ali H. Brivanlou demonstrated that the protein Activin causes embryonic frog cells to take on traits specific to certain tissue types, a process called differentiation. For decades now, Activin has been thought to instigate the transition from homogenous clump to specialized cells.
“Activin was the textbook definition of a molecule that is necessary and sufficient for differentiation,” says Brivanlou, the Robert and Harriet Heilbrunn Professor. “Researchers had shown that the dose of the protein determines cellular fate. At a very high dose, for example, you get gut and muscle; and at a very low dose, you get nerve tissue.”
