The Sox2 protein is an early marker of neural tissue. Imagine a researcher removes a region of cells from an area of a gastrulating embryo he believes to be neural-specified, and places them in neutral culture medium; however, he doesn't observe any Sox2 expression after several days, and the cells do not take on a neuron-like appearance. What could be an explanation for this?
| A. |
The removed cells are not specified, but rather determined to form neurons. |
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| B. |
The removed cells have already differentiated into neurons, and no longer express any neural-specific proteins. |
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| C. |
The removed cells have to be exposed to a variety of “non-neutral” proteins, in order to demonstrate neural specification. |
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| D. |
The removed cells are not neural-specified, but are instead to fated form some other cell type, like intestinal cells |
Answer c. The removed cells have to be exposed to a variety of “non-neutral” proteins, in order to demonstrate neural specification.
Various signaling molecules play an important role in converting stem cells into neuron. Hence, the stem cell removed from the embryo will not differentiate into embryo until exposed to specific signaling proteins.
The Sox2 protein is an early marker of neural tissue. Imagine a researcher removes a region...