More specifically I want to know how a cell transcribes the actual transcription factor protein itself and how it knows which transcription factor to transcribe? Which relates to zygote develop to full differentiated cells, so a simple guide through that development would be nice to complete my understand of this area.
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Induction is one process. Signals from another cell tell the cell of interest to produce a particular protein -- a particular transcription factor. That turns on that gene. The gene can remain on by several different processes. For example, the gene for the transcription factor can have an enhancer that binds the transcription factor itself - thus the product of the gene causes the gene to be transcribed, forming a self-reinforcing loop.
Morphogens are diffusable substances that can form concentration gradients; higher near the cells that secrete them and lower the more distant from those cells. Cells can respond differently to the same morphogen based on the concentration at their location; if the level is high, they might transcribe protein Xl if the level is intermediate, they might trasnscribe protein Y; if the concentration is low, they might transcribe neither.
That's a single morphogen gradient, but a cell can bathed in multiple ones simultaneously, since cells can be above, below, in front of, behind, to the left, and to the right of it. And a cell just a few millimeter away from it can have different concentrations of all those signals. Thus, very complex signalling can result, producing a wide variety of gene expression.
Further, a cell can become competent to respond to a signal. Earlier, it could be bathed in the morphogen and not respond at all - but once a prerequeist signal hits the cell, then it can respond. So timing, in additional to 3 dimensions of space, is also a factor.
The initial signal usually comes from the egg itself. Transcription factors can be confined to a certain region of the egg. Then when cleavage occurs, they get sequestered into only a few, specific cells. These cells secrete a morphogen, and kick off a chain reaction of cells signalling cells, causing differental gene expression.
Morphogens are diffusable substances that can form concentration gradients; higher near the cells that secrete them and lower the more distant from those cells. Cells can respond differently to the same morphogen based on the concentration at their location; if the level is high, they might transcribe protein Xl if the level is intermediate, they might trasnscribe protein Y; if the concentration is low, they might transcribe neither.
That's a single morphogen gradient, but a cell can bathed in multiple ones simultaneously, since cells can be above, below, in front of, behind, to the left, and to the right of it. And a cell just a few millimeter away from it can have different concentrations of all those signals. Thus, very complex signalling can result, producing a wide variety of gene expression.
Further, a cell can become competent to respond to a signal. Earlier, it could be bathed in the morphogen and not respond at all - but once a prerequeist signal hits the cell, then it can respond. So timing, in additional to 3 dimensions of space, is also a factor.
The initial signal usually comes from the egg itself. Transcription factors can be confined to a certain region of the egg. Then when cleavage occurs, they get sequestered into only a few, specific cells. These cells secrete a morphogen, and kick off a chain reaction of cells signalling cells, causing differental gene expression.
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DNAunion pretty much got it all.
There's cytoplasmic determinants, placed in zygote by the mother which for example in the case of the Bicoid gene, establishes the anterior region of the embryo.
Induction is another one.
Morphogens like the Apical ectodermal ridge in chicks and the Zone of polarizing activity, are hox genes and also establish body parts by relying on concentration gradients.
Hormones differentiate cells also
Hmnn...There's also environmental factors like in the case of frogs where they can be more omnivorous or carnivorous, depending on the amount of food in their habitats.
There's cytoplasmic determinants, placed in zygote by the mother which for example in the case of the Bicoid gene, establishes the anterior region of the embryo.
Induction is another one.
Morphogens like the Apical ectodermal ridge in chicks and the Zone of polarizing activity, are hox genes and also establish body parts by relying on concentration gradients.
Hormones differentiate cells also
Hmnn...There's also environmental factors like in the case of frogs where they can be more omnivorous or carnivorous, depending on the amount of food in their habitats.