How is cell differentiation made possible?

All human cells are derived from a single cell, the zygote. Therefore, all cells contain the same genetic information. But a cell from the central nervous system is different from the respiratory epithelium, by structure and function.

How is such a differentiation made possible?

DNA

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JibrilABS
JibrilABS
1 year ago

As the zygote divides by rapid mitosis through the morula stage to gastrulation, all the so formed pluripotent cells migrate to different locations (? chemo attractants) and depending on the factors present at the location a cell finds itself, certain genes are expressed and others are not.

So while all the cells in a body contain the same genome, some genes expressed by a cell in the CNS are not expressed by the cells lining the GIT or the cornea. That’s why such different cells have different enzymes and structures therefore different functions and abilities.

In short, it all goes down to gene expression. Molecular 👌

The_TRuTH
The_TRuTH
1 year ago

The zygote is a Totipotent cell( i.e. it’s capable of forming other cells in the body)
As embryology continues the zygote begins to undergo division (cleavage)
The division called cleavage begins to form multiple cells, from morula to blastula to gastrula then the three germ layer formed
After the formation of these three germ layer. Based on the individual tissues and organ that each of these germ layers would give rise to, the cells of these germ layers will begin to undergo cellular differentiation, and this cellular differentiation would allow them gain some functions or lose some functions. Then their DNA will now become differentially expressed.
Basically in cellular differentiation some genes in the cells of the ectoderm would be expressed while some would be expressed while some would be shut off, same thing goes for other germ layer. In order words, only the genes responsible for the expression of a particular organ or a particular tissue or a particular protein for that particular germ layer would be expressed, take for example a cell that wants to become a skin Cell(skin cells are on the ectoderm) so a cell that wants to become an skin cell has the complete DNA from the zygote but only the part of the DNA that’s responsible for coding for melanin and other skin proteins would be expressed, likewise a cell that wants to differentiate into the neurons, spinal cord, the brain or nervous system in general, it has the complete genome, but only a part of the DNA responsible for Cell division or reproduction would be shut off, while the part responsible for elongation, sensitivity to electrical impulse and the likes would be turned on.
All cells in the organism contains the Same genetic material but not all the part of the genetic material is expressed the same way in every cell, the organ or tissue the cell is trying to become would determine which Gene would be turned on or shut off. This situation is what we call differential Gene expression.
Differential Gene expression makes it possible for cells from the nervous system would be different from cells in the respiratory epithelium by structure and function

Last edited 1 year ago by The_TRuTH